The charcoal from ashes found in a cave gave 7.4 14C counts per gram per minute. Wood from the outer portion of a growing tree gives a comparable count of 15.3. The half-life of 14C is 5700 years.
How old are the ashes?
A) 3245 y
B) 5700 y
C) 5970 y
D) 9220 y
E) 5437 y

Answers

Answer 1

Answer:

C) 5970 y

Explanation:

Given;

initial amount of wood, N₀ = 15.3 cpm/g

remaining amount of wood (charcoal), N = 7.4 cpm/g

half life of carbon 14, t 1/2 = 5700 years

The age of the ashes can be calculated using the following formula;

[tex]N = N_0(\frac{1}{2})^{\frac{t}{t_1_/_2} }\\\\(\frac{1}{2})^{\frac{t}{t_1_/_2} } = \frac{N}{N_0} \\\\(\frac{1}{2})^{\frac{t}{t_1_/_2} } = \frac{7.4}{15.3} \\\\(\frac{1}{2})^{\frac{t}{t_1_/_2} } = 0.48366\\\\t = t_{1/2} Log\frac{1}{2} (0.48366)\\\\t = \frac{t_{1/2}ln(0.48366)}{-ln(2)} \\\\t = t_{1/2}(1.0479)\\\\t = 5700(1.0479)\\\\t = 5973 \ years\\\\t = 5970 \ years(nearest \ ten)[/tex]

Therefore, the ashes are 5970 years


Related Questions

What is the pH of a 0.02M solution of sodium acetate (pka=4.74) to which you add HCl to a final concentration of 0.015M?

Answers

Answer:

pH = 5.22

Explanation:

As you can see, your initial concentration of sodium acetate (NaCH₃COO) is 0.02M (0.02mol /L). When you add HCl, the reaction is:

NaCH₃COO + HCl → CH₃COOH + NaCl.

If you add HCl, and final concentration of NaCH₃COO is 0.015M, the concentration of CH₃COOH is 0.005M.

You can know the pH of this solution using H-H equation:

pH = pKa + log {NaCH₃COO} / {CH₃COOH}

pH = 4.74 +  log {0.015M} / {0.005M}

pH = 5.22

What are the solutions to the quadratic equation 2x2 + 10x - 48 = 0?

Answers

Answer:

x = 3 , x= -8

Explanation:

[tex]2x^2+10x-48\\=2\left(x^2+5x-24\right)\\x^2+5x-24\\=\left(x^2-3x\right)+\left(8x-24\right)\\=x\left(x-3\right)+8\left(x-3\right)\\=\left(x-3\right)\left(x+8\right)\\=2\left(x-3\right)\left(x+8\right)\\2\left(x-3\right)\left(x+8\right)=0\\x-3=0\\x = 0+3\\x = 3\\x+8=0\\x+8-8=0-8\\x=-8\\x=3,\:x=-8[/tex]

Aluminum and oxygen react according to the following equation: 4Al + 3O2 -> 2Al2O3 In a certain experiment, 4.6g Al was reacted with excess oxygen and 6.8g of product was obtained. What was the percent yield of the reaction?

Answers

Answer:

Percent yield: 78.2%

Explanation:

Based on the reaction:

4Al + 3O₂ → 2Al₂O₃

4 moles of Al produce 2 moles of Al₂O₃

To find percent yield we need to find theoretical yield (Assuming a yield of 100%) and using:

(Actual yield (6.8g) / Theoretical yield) × 100

Moles of 4.6g of Al (Molar mass: 26.98g/mol) are:

4.6g Al × (1mol / 26.98g) = 0.1705 moles of Al.

As 4 moles of Al produce 2 moles of Al₂O₃, theoretical moles of Al₂O₃ obtained from 0.1705 moles of Al are:

0.17505 moles Al × (2 moles Al₂O₃ / 4 moles Al) = 0.0852 moles of Al₂O₃,

In grams (Molar mass Al₂O₃ = 101.96g/mol):

0.0852 moles of Al₂O₃ × (101.96g / mol) =

8.7g of Al₂O₃ can be produced (Theoretical yield)

Thus, Percent yield is:

(6.8g / 8.7g) × 100 =

78.2%

Which is one characteristic of producers?
They recycle nutrients.
They do not eat other organisms.
They break down waste for energy.
They use other organisms for energy.

Answers

Answer: They use other organisms for energy

Explanation:

Answer:

they use other organisms for energy

Explanation: d

A student mixes wants to prepare 24.1 mmol of benzamide from benzoyl chloride and NH4OH. If the student uses excess 15 M NH4OH, how many mL of Benzoyl chloride must be used

Answers

Answer:

2.81mL

Explanation:

Based on the reaction:

C₆H₃COCl + 2NH₃ → C₆H₅CONH₂ + NH₄Cl

Benzoyl chloride + ammonia → Benzamide

1 mole of benzoyl chloride in excess of ammonia produce 1 mole of Benzamide.

Thus, assuming a theoretical yield, to produce 24.1mmoles of benzamide you require 24.1mmoles of benzoyl chloride.

As molar mass of benzoyl chloride is 141g/mol, mg you require are:

mg Benzoyl chloride: 24.1mmol × (141mg / 1mmol) = 3398.1mg = 3.3981g of benzoyl chloride.

to convert this mass to mL, you require density of Benzoyl chloride (1.21g/mL). Thus, mL you need are:

3.3981g × (1mL / 1.21g) =

2.81mL

Balance this equation: __ UO2(s) + __ HF(ℓ) → __ UF4(s) + __ H2O(ℓ) Though you would not normally do so, enter the coefficient of "1" if needed. UO2(s) HF(ℓ) UF4(s) H2O(ℓ)

Answers

Answer:

The balanced equation is given below:

UO2(s) + 4HF(l) —› UF4(s) + 2H2O(l)

The coefficients are: 1, 4, 1, 2

Explanation:

UO2(s) + HF(l) —› UF4(s) + H2O(l)

The above equation can be balance as follow:

There are 2 atoms of O on the left side and 1 atom on the right side. It can be balanced by writing 2 in front of H2O as shown below:

UO2(s) + HF(l) —› UF4(s) + 2H2O(l)

There are 4 atoms of F on the right side and 1 atom on the left side. It can be balanced by writing 4 in front of HF as shown below:

UO2(s) + 4HF(l) —› UF4(s) + 2H2O(l)

Now, the equation is balanced.

The coefficients are: 1, 4, 1, 2.

If the concentration of Mg2+ in the solution were 0.039 M, what minimum [OH−] triggers precipitation of the Mg2+ ion? (Ksp=2.06×10−13.) Express your answer to two significant figures and include the appropriate units. nothing nothing

Answers

Answer:

2.30 × 10⁻⁶ M

Explanation:

Step 1: Given data

Concentration of Mg²⁺ ([Mg²⁺]): 0.039 M

Solubility product constant of Mg(OH)₂ (Ksp): 2.06 × 10⁻¹³

Step 2: Write the reaction for the solution of Mg(OH)₂

Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)

Step 3: Calculate the minimum [OH⁻] required to trigger the precipitation of Mg²⁺ as Mg(OH)₂

We will use the following expression.

Ksp = 2.06 × 10⁻¹³ = [Mg²⁺] × [OH⁻]²

[OH⁻] = 2.30 × 10⁻⁶ M

Using the Ideal Gas Law, PV = nRT and the information below, solve the question. 5.01 moles of chlorine are held in a vessel with a fixed volume of 70L. What is the pressure of the gas in atm, if its temperature is 303K. REMEMBER TO USE R=0.08206L*atm / k*mol

Answers

Answer:

1.7795 atm

Explanation:

[tex]n = 5.01\\V = 70L\\P = ?\\T = 303K\\R = 0.08206\\\\PV =nRT\\Make \:P \:Subject\:of\:the\:formula\\P = \frac{nRT}{V} \\\\P = \frac{5.01\times0.08206\times303}{70} \\\\P =\frac{124.5695}{70}\\ P = 1.7795[/tex]

Calculate the molality of a solution prepared by dissolved 19.9 g of kcl in 750ml of water

Answers

First, we find the molar mass of KCl which is AK+ACl=39+35.5=74.5g/mole

now we find out the number of moles by dividing the given mass to the molar mass n=m/M=19.9/74.5=0.26 moles. The molarity of a solution is equal to the number of moles divided by the volume of the solution. =0.26moles/0.75liters=0.346M

What is the energy change associated with 1.5 mole of D being formed? 

Answers

Answer:

–36 KJ.

Explanation:

The equation for the reaction is given below:

2B + C —› D + E. ΔH = – 24 KJ

From the equation above,

1 mole of D required – 24 KJ of energy.

Now, we shall determine the energy change associated with 1.5 moles of D.

This can be obtained as illustrated below:

From the equation above,

1 mole of D required – 24 KJ of energy

Therefore,

1.5 moles of D will require = 1.5 × – 24 = –36 KJ.

Therefore, –36 KJ of energy is associated with 1.5 moles of D.

The overall process that uptakes energy-poor molecules (CO2 and H2O) from their reservoirs in nature and converts them into energy-rich molecules is

Answers

Answer:

Photosynthesis

Explanation:

Photosynthesis is a process by  which photosynthetic organisms use the energy of captured sunlight to convert energy-poor molecules such as carbon (iv), CO₂ and water (H₂O) into energy-rich organic molecules sch as carbohydrates e.g. glucose.

Photosynthesis occurs in a variety of bacteria  and algae as well in vascular plants. The overall equation for the reaction of photosynthesis is as follows:

CO₂ + H₂O + light------->  (CH₂O) + O₂

It is a redox reaction in which  water donates electrons (as hydrogen) for the reduction of  CO₂ to carbohydrate, (CH₂O).

Carbohydrates are energy-rich molecules which serves as energy sources for many living organisms.

A student obtained a clean flask. She weighed the flask and stopper on an analytical balance and found the total mass to be 34.232 g. She then filled the flask with water and found the new mass to be 60.167 g. The temperature of the water was measured to be

Answers

Answer:

25.99mL is the volume internal volume of the flask

Explanation:

To complete the question:

The temperature of the water was measured to be 21ºC. Use this data to find the internal volume of the stoppered flask

The flask was filled with water, that means the internal volume of the flask is equal to the volume that the water occupies.

To find the volume of the water you need to find the mass and by the use of density of water at 21ºC (0.997992g/mL), you can find the volume of the flask, thus:

Mass water = Mass filled flask - Mass of clean flask

Mass water = 60.167g - 34.232g

Mass water = 25.935g of water.

To convert this mass to volume:

25.935g × (1mL / 0.997992g) =

25.99mL is the volume internal volume of the flask

Sometimes a nuclide is referenced by the name of the element followed by the:______
a. atomic number
b. mass number
c. electrical charge
d. none of the above

Answers

Answer:

The correct option is d

Explanation:

Nuclide is synonymous with groups of electrons or protons, that is, a nuclide is the grouping of nucleons.

Review the reversible reactions given, along with the associated equilibrium constant Kat room temperature. In each case, determine whether the forward or reverse reaction is favored.
CH3COOH → CH3C00^- + H^+
Ka=1.8 x 10^-5
AgCl → Ag^+ + Cl^-
Ksp=1.6 x 10^-10
Al(OH)3 → Al^3+ + 3OH^-
Ksp=3.7 x 10^-15
A+B → C
K=4.9 x 10^3

Answers

Answer:

The answers to your questions are given below

Explanation:

The following data were obtained from the question:

CH3COOH → CH3C00^- + H^+

Equilibrium constant, Ka = 1.8 x 10^-5

AgCl → Ag^+ + Cl^-

Equilibrium constant, Ksp = 1.6 x 10^-10

Al(OH)3 → Al^3+ + 3OH^-

Equilibrium constant, Ksp = 3.7 x 10^-15

A+B → C

Equilibrium constant, K = 4.9 x 10^3

When the value of the equilibrium constant is grater than 1, it shows that the concentration of product is higher than that of the reactant and it implies that the forward reaction is favored.

When the value of the equilibrium constant is 1, it shows that the the concentration of the product and reactant are the same. Therefore neither the forward nor the reverse reaction is favored.

When the value of the equilibrium constant is lesser than 1, it shows that the concentration of the reactant is higher than the concentration of the product. Therefore, the reversed reaction is favored.

Now, we shall the question given above as follow:

A. CH3COOH → CH3C00^- + H^+

Equilibrium constant, Ka = 1.8 x 10^-5

Since the value of the equilibrium constant is lesser than 1, it means that the reverse reaction is favored.

B. AgCl → Ag^+ + Cl^-

Equilibrium constant, Ksp = 1.6 x 10^-10

Since the value of the equilibrium constant is lesser than 1, it means that the reverse reaction is favored.

C. Al(OH)3 → Al^3+ + 3OH^-

Equilibrium constant, Ksp = 3.7 x 10^-15

Since the value of the equilibrium constant is lesser than 1, it means that the reverse reaction is favored.

D. A+B → C

Equilibrium constant, K = 4.9 x 10^3

Since the value of the equilibrium constant is greater than 1, it means that the forward reaction is favored.

The reaction conditions are:

A. The reverse reaction is favored.

B. The reverse reaction is favored.

C. The reverse reaction is favored.

D. The forward reaction is favored.

Chemical reaction:

A. [tex]CH_3COOH[/tex] → [tex]CH_3COO^- + H^+[/tex]

Equilibrium constant, Ka = [tex]1.8 * 10^{-5}[/tex]

B. [tex]AgCl[/tex] → [tex]Ag^+ + Cl^-[/tex]

Equilibrium constant, Ksp = [tex]1.6 * 10^{-10}[/tex]

C. [tex]Al(OH)_3[/tex] → [tex]Al^{3+} + 3OH^-[/tex]

Equilibrium constant, Ksp = [tex]3.7 * 10^{-15}[/tex]

D. A+B → C

Equilibrium constant, K = [tex]4.9 * 10^3[/tex]

Conditions for Equilibrium constant:

When the value of the equilibrium constant is greater than 1, it shows that the concentration of product is higher than that of the reactant and it implies that the forward reaction is favored.

When the value of the equilibrium constant is 1, it shows that the the concentration of the product and reactant are the same. Therefore neither the forward nor the reverse reaction is favored.

When the value of the equilibrium constant is lesser than 1, it shows that the concentration of the reactant is higher than the concentration of the product. Therefore, the reversed reaction is favored.

Thus, the reactions will be:

A. The reverse reaction is favored.

B. The reverse reaction is favored.

C. The reverse reaction is favored.

D. The forward reaction is favored.

Find  more information about Equilibrium constant here:

brainly.com/question/12858312

Which sample is most likely to experience the smallest temperature change upon observing 55KJ of heat? 

Answers

Answer:

100 g of water: specific heat of water 4.18 J/g°C

Explanation:

To know the correct answer to the question, we shall determine the temperature change in each case.

For 100 g of water:

Mass (M) = 100 g

Specific heat capacity (C) = 4.18 J/g°C

Heat absorbed (Q) = 55 KJ = 55000 J

Change in temperature (ΔT) =..?

Q = MCΔT

55000 = 100 x 4.18 x ΔT

Divide both side by 100 x 4.18

ΔT = 55000/ (100 x 4.18)

ΔT = 131.6 °C

Therefore the temperature change is 131.6 °C

For 50 g of water:

Mass (M) = 50 g

Specific heat capacity (C) = 4.18 J/g°C

Heat absorbed (Q) = 55 KJ = 55000 J

Change in temperature (ΔT) =..?

Q = MCΔT

55000 = 50 x 4.18 x ΔT

Divide both side by 50 x 4.18

ΔT = 55000/ (50 x 4.18)

ΔT = 263.2 °C

Therefore the temperature change is 263.2 °C

For 50 g of lead:

Mass (M) = 50 g

Specific heat capacity (C) = 0.128 J/g°C

Heat absorbed (Q) = 55 KJ = 55000 J

Change in temperature (ΔT) =..?

Q = MCΔT

55000 = 50 x 0.128 x ΔT

Divide both side by 50 x 0.128

ΔT = 55000/ (50 x 0.128)

ΔT = 8593.8 °C

Therefore the temperature change is 8593.8 °C.

For 100 g of iron:

Mass (M) = 100 g

Specific heat capacity (C) = 0.449 J/g°C

Heat absorbed (Q) = 55 KJ = 55000 J

Change in temperature (ΔT) =..?

Q = MCΔT

55000 = 100 x 0.449 x ΔT

Divide both side by 100 x 0.449

ΔT = 55000/ (100 x 0.449)

ΔT = 1224.9 °C

Therefore the temperature change is 1224.9 °C.

The table below gives the summary of the temperature change of each substance:

Mass >>> Substance >> Temp. Change

100 g >>> Water >>>>>> 131.6 °C

50 g >>>> Water >>>>>> 263.2 °C

50 g >>>> Lead >>>>>>> 8593.8 °C

100 g >>> Iron >>>>>>>> 1224.9 °C

From the table given above we can see that 100 g of water has the smallest temperature change.

Which Carbon is the triple bound attached to in 6-ethyl-2-octyne?
-first
-fourth
-third
-second

Answers

Answer:

-second

Explanation:

6-ethyl-2-octyne is an unsaturated compound with a triple bond.

6-ethyl-2-octyne will have a triple bound attached to the second carbon. The suffix -yne suggests that compound carry a triple bond and the number  "2" before suffix refers to the position of triple bond that is second carbon.

Hence, the correct option is  "-second ".

Identify the elements that have the following abbreviated electron configurations.
A) [Ne] 3s23p5.
B) [Ar] 4s23d7.
C) [Xe] 6s1.

Answers

Answer:

A) Chlorine (Cl)

B) Cobalt (Co)

C) Caesium (Cs)

Hope this helps.

The abbreviated electron configurations that was given in the question belongs to

Chlorine (Cl)

Cobalt (Co)

Caesium (Cs) respectively.

Electronic configurations can be regarded as the  electronic structure, which is the way an electrons is arranged in energy levels towards an atomic nucleus.

The electron configurations is very useful when  describing  the orbitals of an atom in its ground state.

To calculate an electron configuration, we can put the periodic table into sections, and this section will represent the atomic orbitals which is the  regions that house the electrons.

Groups one of the period table and two belongs to s-block, group  3 through 12 belongs to the d-block, while  13 to 18 can be attributed to p-block ,The  rows that is found at bottom are the f-block

Therefore, electron configurations  explain orbitals of an atom when it is in it's ground state.

Learn more at:https://brainly.com/question/21940070?referrer=searchResults

Calculate the pH of a buffer solution obtained by dissolving 25.025.0 g of KH2PO4(s)KH2PO4(s) and 38.038.0 g of Na2HPO4(s)Na2HPO4(s) in water and then diluting to 1.00 L.

Answers

Answer:

pH = 7.37

Explanation:

The buffer H₂PO₄⁻/HPO₄²⁻ has as pKa 7.21. To find the pH of a buffer you can use H-H equation:

pH = pKa + log₁₀ [HPO₄²⁻] / [H₂PO₄⁻]

Where [HPO₄²⁻] and [H₂PO₄⁻] are molar concentrations of each species. As volume is 1.00L, [HPO₄²⁻] and [H₂PO₄⁻] are MOLES.

Moles of 25.0g of KH₂PO₄ (Molar mass: 136.086g/mol):

25.0g KH₂PO₄ ₓ (1mol / 136.086g) = 0.1837 moles KH₂PO₄ = moles H₂PO₄⁻

Moles of 38.0g of Na₂HPO₄ (Molar mass: 141.96g/mol):

38.0g KH₂PO₄ ₓ (1mol / 141.96g) = 0.2677 moles Na₂HPO₄ = moles HPO₄²⁻

Replacing in H-H equation:

pH = pKa + log₁₀ [HPO₄²⁻] / [H₂PO₄⁻]

pH = 7.21 + log₁₀ [0.2677] / [0.1837]

pH = 7.37

The NMR spectrum of your final compound will contain extra peaks that were not present in your starting material. For what hydrogen nuclei do those peaks occur?

Answers

Answer:

The peaks are registered from tetramethyl silane (TMS)

Explanation:

Tetramethyl silane (TMS) is used as internal reference in proton nmr (H NMR) spectrometry.

Its peak is usually registered at about a 2.0 chemical shift means that the hydrogen atoms which caused that peak need a magnetic field two millionths less than the field needed by TMS to produce resonance. This is not affected by the chemical shift of the sample analysed.

I hope this helped.

Which one of the following reactions must be carried out in an electrolytic cell rather than in an electrochemical cell?

a. Zn2+ + Ca → Zn + Ca2+
b. Al3+ + 3Br– → Al + (3/2)Br2
c. 2Al + 3Fe2+ → 2Al3+ + 3Fe
d. H2 + I2(s) → 2H+ + 2I–

Answers

Answer:

b. Al3+ + 3Br– → Al + (3/2)Br2

Explanation:

If we look at this reaction closely, aluminum was reduced while bromine was oxidized. The reduction potential of aluminum is -1.66 V while that of bromine is + 1.087. Recall that the more negative the redox potential of a chemical specie, the greater its tendency to function as a reducing agent donating electrons in an electrochemical reaction.

However, in this reaction, aluminium is found to accept rather than donate electrons. Therefore, the process is non spontaneous and can only occur in an electrolytic cell, hence the answer.

b. [tex]Al^{3+} + 3 Br^{-}[/tex] → [tex]Al + \frac{3}{2} Br_{2}[/tex]

Electrolytic  Cell v/s Electrochemical Cell:

Electrochemical cells convert chemical energy into electrical energy or vice versa while an electrolytic cell is a type of electrochemical cell in which electrical energy is converted into chemical energy.Electrochemical cells consist of a cathode (+) and an anode(-) while Electrolytic cells consist of a positively charged anode and a negatively charged cathode.

Out of the given reactions, [tex]Al^{3+} + 3 Br^{-}[/tex] → [tex]Al + \frac{3}{2} Br_{2}[/tex]  is carried out in an electrolytic cell rather than in an electrochemical cell.

As we know, In electrolytic cells, like galvanic cells, are composed of two half-cells

one is a reduction half-cell, the other is an oxidation half-cell.

In the given reaction, aluminum is being reduced while bromine gets oxidized and the value of reduction potential of aluminum is -1.66 V while that of bromine is + 1.087. Therefore, the process is non spontaneous and can only occur in an electrolytic cell.

Learn more:

https://brainly.com/question/21722989

A gas of unknown identity diffuses at a rate of 155 mL/s in a diffusion apparatus in which carbon dioxide diffuses at the rate of 102 mL/s. Calculate the molecular mass of the unknown gas.

Answers

Answer:

19.07 g mol^-1

Explanation:

The computation of the molecular mass of the unknown gas is shown below:

As we know that

[tex]\frac{Diffusion\ rate\ of unknown\ gas }{CO_{2}\ diffusion\ rate} = \frac{\sqrt{CO_{2\ molar\ mass}} }{\sqrt{Unknown\ gas\ molercular\ mass } }[/tex]

where,

Diffusion rate of unknown gas = 155 mL/s

CO_2 diffusion rate = 102 mL/s

CO_2 molar mass = 44 g mol^-1

Unknown gas molercualr mass = M_unknown

Now placing these values to the above formula

[tex]\frac{155mL/s}{102mL/s} = \frac{\sqrt{44 g mol^{-1}} }{\sqrt{M_{unknown}} } \\\\ 1.519 = \frac{\sqrt{44 g mol^{-1}} }{\sqrt{M_{unknown}} } \\\\ {\sqrt{M_{unknown}} } = \frac{\sqrt{44 g mol^{-1}}}{1.519} \\\\ {\sqrt{M_{unknown}} } = \frac{44 g mol^{-1}}{(1.519)^{2}}[/tex]

After solving this, the molecular mass of the unknown gas is

= 19.07 g mol^-1

A reaction has the rate law, rate = k[A]3[B]. Which change will cause the great­est in­crease in the reaction rate?

Answers

Answer:

Increasing the concentration of A will cause the greatest change over the rate.

Explanation:

Hello,

In this case, considering the given rate law, which is third-order with respect to A, changing its concentration, the rate will be significantly modified. For instance, suppose a concentration of A and B of 1M and a symbolic rate constant (k),  this causes the rate to be:

[tex]r=k[1M]^3[1M]=1k\frac{M^4}{s}[/tex]

Then, if we change the concentration of A to 2 M holding the concentration of B in 1 M, the new rate constant will be:

[tex]r=k[2M]^3[1M]=8k\frac{M^4}{s}[/tex]

Nevertheless, if we hold the concentration of A in 1 M and the concentration of B is now 2 M (same change), the new rate constant is:

[tex]r=k[1M]^3[2M]=2k\frac{M^4}{s}[/tex]

It means that increasing the concentration of A will cause the greatest change over the rate.

Best regards.

The change in concentration of A will cause the great­est in­crease in the reaction rate.

Rate of reaction :

Given reaction has rate law ,

          [tex]rate=k[A]^{3} [B][/tex]

which is third-order with respect to concentration of A

From rate law equation, It is observed that the degree of concentration of A is three.

It means that small change in concentration of A result large change in rate of reaction.Thus, the change in concentration of A  will cause the great­est in­crease in the reaction rate.

Learn more about the rate of reaction here :

https://brainly.com/question/23637409

a. How many moles of copper equal 8.00 × 109 copper atoms?
b. How many moles of calcium equal 102.5 g calcium?
c. How many atoms of lead are present in 5.04 g lead?
d. How many aluminum atoms are present in 2.85 moles of aluminum?
e. What is the mass in grams of 1.08 × 103 moles of fluorine gas?
f. How many molecules of benzene (C6H6) are present in 0.584 g of benzene?
g. What is the mass of 5.09 × 109 atoms of hydrogen gas?
h. How many calcium atoms are present in 0.45 mol Ca3PO4?

Answers

Answer:

Explanation:

a ) one mole = 6.02 x 10²³ atoms

no of moles in given no of atoms

= 8 x 10⁹ / 6.02 x 10²³

= 1.329 x 10⁻¹⁴ moles .

b ) one mole of calcium = 40 gram

102 .5 g calcium

= 102 .5 / 40 moles

= 2.5625 moles

c )

no of moles in 5.04 g lead = 5.04 / 207

= 2.4347 x 10⁻² moles

= 2.4347 x 10⁻²x 6.02 x 10²³ no of atoms of lead

= 14.6568 x 10²¹ no of atoms .

d)  

one mole = 6.02 x 10²³ atoms

2.85 mole = 17.157 x 10²³ atoms .

e )

moles of fluorine gas = 1.08 x 10³ / 6.02 x 10²³

= .1794 x 10⁻²⁰ moles

mass in grams =  .1794 x 10⁻²⁰ x 38

= 6.8172 x 10⁻²⁰ grams

f )

no of moles in .584 g of benzene = .584 / 78

= 7.487 x 10⁻³ moles

no of molecules = 6.02 x 10²³ x  7.487 x 10⁻³

= 45.07 x 10²⁰ molecules .

g )

moles of atoms = 5.09 x 10⁹ / 6.02 x 10²³

= .8455 x 10⁻¹⁴ moles

mass in gram = .8455 x 10⁻¹⁴ x 1

=  .8455 x 10⁻¹⁴ g

h )

.45 moles of Ca₃PO₄ = .45 x 6.02 x 10²³ molecules

= 2.709 x 10²³ molecules of Ca₃PO₄

no of atoms of Ca = 3 x 2.709 x 10²³

= 8.127 x 10²³ atoms of Ca .

A volume of 30.0 mL of a 0.140 M HNO3 solution is titrated with 0.570 M KOH. Calculate the volume of KOH required to reach the equivalence point.

Answers

Answer:

7.37 mL of KOH

Explanation:

So here we have the following chemical formula ( already balanced ), as HNO3 reacts with KOH to form the products KNO3 and H2O. As you can tell, this is a double replacement reaction,

HNO3 + KOH → KNO3 + H2O

Step 1 : The moles of HNO3 here can be calculated through the given molar mass (  0.140 M HNO3 ) and the mL of this nitric acid. Of course the molar mass is given by mol / L, so we would have to convert mL to L.

Mol of NHO3 = 0.140 M [tex]*[/tex] 30 / 1000 L = 0.140 M [tex]*[/tex] 0.03 L = .0042 mol

Step 2 : We can now convert the moles of HNO3 to moles of KOH through dimensional analysis,

0.0042 mol HNO2 [tex]*[/tex] ( 1 mol KOH / 1 mol HNO2 ) = 0.0042 mol KOH

From the formula we can see that there is 1 mole of KOH present per 1 moles of HNO2, in a 1 : 1 ratio. As expected the number of moles of each should be the same,

Step 3 : Now we can calculate the volume of KOH knowing it's moles, and molar mass ( 0.570 M ).

Volume of KOH = 0.0042 mol [tex]*[/tex] ( 1 L / 0.570 mol ) [tex]*[/tex] ( 1000 mL / 1 L ) = 7.37 mL of KOH

g For the following reaction, 20.9 grams of iron are allowed to react with 9.19 grams of oxygen gas . iron(s) oxygen(g) iron(II) oxide(s) What is the maximum mass of iron(II) oxide that can be formed

Answers

Answer:

26.87g

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2Fe + O2 —> 2FeO

Next, we shall determine the masses of Fe and O2 that reacted and the mass of FeO produced from the balanced equation.

This is illustrated below:

Molar mass of Fe =56 g/mol

Mass of Fe from the balanced equation = 2 x 56 = 112 g

Molar mass of O2 = 16x2 = 32 g/mol

Mass of O2 from the balanced equation = 1 x 32 = 32 g

Molar mass of FeO = 56 + 16 =72 g/mol

Mass of FeO from the balanced equation = 2 x 72 = 144 g

From the balanced equation above,

112 g of Fe reacted with 32 g of O2 to produce 144 g of FeO.

Next, we shall determine the limiting reactant.

This is illustrated below:

From the balanced equation above,

112 g of Fe reacted with 32 g of O2.

Therefore, 20.9 g of Fe will react with = (20.9 x 32)/112 = 5.97 g of O2.

From the calculations made above, we can see that only 5.97 g out of 9.19 g of O2 given were required to react completely with 20.9 g of Fe.

Therefore, Fe is the limiting reactant and O2 is the excess reactant.

Finally, we shall determine the mass of FeO produced from the reaction.

In this case, the limiting reactant will be used, as it will give the maximum yield of the reaction since all of it is used up in the reaction.

The limiting reactant is Fe and the maximum mass of FeO produced can be obtained as follow:

From the balanced equation above,

112 g of Fe reacted to produce 144 g of FeO.

Therefore, 20.9 g of Fe will react to produce = (20.9 x 144)/112 = 26.87g of FeO.

Therefore, the maximum mass of iron(II) oxide, FeO produced is 26.87g.

g Increasing the number of unsaturations in a fatty acid ____________ the melting temperature of the fatty acid.

Answers

Answer:

Decreases

Explanation:

Fatty acid which have the double bond or triple bond are called unsaturated fatty acids. Because of the double or triple bond, unsaturated fatty acids are loosely packed and form some distance among molecules which lowers the melting point of unsaturated fatty acids.

So, if the unsaturation of fatty acid will increase, it leads to more branched and loosely packed molecules and decreases the melting temperature accordingly.

which of the following compounds exhibits dipole -dipole forces as its strongest attraction between molecules? o2,ch3Br,CCl4,He,BrCH2CH2OH

Answers

Answer:

B. CH3Br

Explanation:

Dipole -Dipole interactions take place in polar molecules.

CH3Br exhibits dipole -dipole forces as its strongest attraction between molecules because it is a polar molecule due to the slightly negative dipole present on the Br molecule.

While O2 is a nonpolar molecule due to its linear structure, CCl4 has zero resultant dipole moment, Helium is non-polar and BrCH2CH2OH is a non polar compound having net dipole moment is zero.

Hence, the correct option is B. CH3Br.

The compound that exhibits dipole -dipole forces is CH3Br

Dipole -Dipole interactions:

It should be taken place in polar molecules. Also, CH3Br should be the strongest attraction that lies between the molecules since it is treated as the polar molecule because of the slightly negative. While on the other hand, O2 should be non-polar molecule because of the linear structure.

Therefore, The compound that exhibits dipole -dipole forces is CH3Br

Learn more about force here: https://brainly.com/question/14379797

A glass cylinder contains 2 gases at a pressure of 106 kPa. If one gas is at 7 kPa, what is the pressure of attributed to the other gas? a) 9 kPa b) 99 kPa c) 113 kPa d) 7 kPa e) 2 kPa (URGENT)

Answers

Answer:

b) 99 kPa

Explanation:

According to Daltons law of partial pressure, the total pressure of a mixture of two or more non reactive gases is the sum of their individual pressures. Let the total pressure of a mixture of n number of gases be [tex]P_{total}[/tex] and their individual pressure be [tex]P_1,P_2,P_3,\ .\ .\ .\ ,\ P_n[/tex], According to Daltons partial pressure law:

[tex]P_{total}=P_1+P_2+P_3+.\ .\ .+P_n[/tex]

Since A glass cylinder contains 2 gases at a pressure of 106 kPa, therefore n = 2. Also one gas ([tex]P_1[/tex]) is at 7 kPa. Using Daltons partial pressure law:

[tex]P_{total}=P_1+P_2+P_3+.\ .\ .+P_n\\P_{total}=P_1+P_2\\106\ kPa=7\ kPa+P_2\\P_2=106\ kPa-7\ kPa\\P_2=99\ kPa[/tex]

In a 74.0-g aqueous solution of methanol, CH4O, the mole fraction of methanol is 0.140. What is the mass of each component?

Answers

Answer:

The correct answer is 16.61 grams methanol and 57.38 grams water.

Explanation:

The mole fraction (X) of methanol can be determined by using the formula,  

X₁ = mole number of methanol (n₁) / Total mole number (n₁ + n₂)

X₁ = n₁/n₁ + n₂ = 0.14

n₁ / n₁ + n₂ = 0.14 ---------(i)

n₁ mole CH₃OH = n₁ mol × 32.042 gram/mol (The molecular mass of CH₃OH is 32.042 grams per mole)

n₁ mole CH₃OH = 32.042 n₁ g

n₂ mole H2O = n₂ mole × 18.015 g/mol  

n₂ mole H2O = 18.015 n₂ g

Thus, total mole number is,  

32.042 n₁ + 18.015 n₂ = 74 ------------(ii)

From equation (i)

n₁/n₁ + n₂ = 0.14

n₁ = 0.14 n₁ + 0.14 n₂

n₁ - 0.14 n₁ = 0.14 n₂

n₁ = 0.14 n₂ / 1-0.14

n₁ = 0.14 n₂/0.86 ----------(iii)

From eq (ii) and (iii) we get,  

32.042 × 0.14/0.86 n₂ + 18.015 n₂ = 74

n₂ (32.042 × 0.14/0.86 + 18.015) = 74

n₂ = 74 / (32.042 × 0.14/0.86 + 18.0.15)

n₂ = 3.1854 mol

From equation (iii),  

n₁ = 0.14/0.86 n₂

n₁ = 0.14/0.86 × 3.1854

n₁ = 0.5185 mol

Now, presence of water in the mixture is,  

= 3.1854 mole × 18.015 gram per mole  

= 57.38 grams

Methanol present in the mixture is,  

= 0.5185 mol × 32.042 gram per mole

= 16.61 grams

Give the electron configuration for the following atoms using appropriate noble gas inner core abbreviation: Bi Cr Sr P 2. Give a set of 4 possible quantum numbers for the most energetic electron(s) of: Bi Cr Sr P n = l = ml = ms = 3. What is the symbol and name of the element with the following electron configuration?

Answers

Answer:

See explanation

Explanation:

The noble gas core electron configuration involves writing the inert gas core of an atom followed by the valence electrons. This is shown for the following atoms;

Bismuth;

[Xe]4f14 5d10 6s2 6p3

Chromium;

[Ar]4s1 3d5

Strontium;

[Kr]5s2

Phosphorus;

[Ne]3s2 3p3

2.

Bi

6p- n=6, l= 1, ml= 1, ms= 1/2

Cr

3d- n=3, l=2, ml=2,ms=1/2

Sr

5s- n=5, l=0, ml=0, ms=1/2

P

3p- n=3, l= 1, ml= 1, ms=1/2

3.

a) Tin (Sn) - [Kr] 5s2 4d10 5p2

b) Caesium (Cs)- [Xe] 6s1

c) Copper (Cu)- [Ar] 4s1 3d10

Other Questions
Help me! Sorry for the other question.... lets try it again! 1/2 x + 3/5 x = 5/4 An 1300-turn coil of wire that is 2.2 cmcm in diameter is in a magnetic field that drops from 0.14 TT to 0 TT in 9.0 msms . The axis of the coil is parallel to the field.What is the emf of the coil? (in V) Explain why a firm might want to continue operating and producing goods even after diminishing marginal returns have set in and marginal cost is rising. A chemist studies the reaction below. 2NO(g) + Cl2(g) 2NOCl(g) He performs three experiments using different concentrations and measures the initial reaction rates (The data from the three experiments is in the table). 1. Write the rate law 2. Solve for k. Tyler is 14 years old. He has just been expelled from school for bringing a knife. He has been arrested on two previous occasions - once for beating up another boy very badly and another time for setting fire to his neighbor's barn. Tyler's parents are at their wit's end and don't know what to do. According to the DSM-5 Tyler would likely be diagnosed with: a. Antisocial Personality Disorder b. Conduct disorder c. Oppositional defiant disorder d. Psychopathy HElp Find the line of symmetry for the parabola whose equation is y = 2x2 - 4x + 1. x = 2 x = -1 x = 1 Cuantos gramos de sulfato de plomo (II) se requieren para preparar 200mL una solucin de esta sal a una concentracin de 100 ppm. Si se toma una muestra de 30 mL de la disolucin anterior y se diluye en 1000 mL de agua, cul es la concentracin de la disolucin? Find the length of x. Please answer this question now Using the unit circle, determine the value of cos(945). Use multiplication to solve the proportion 35/28 = n/12 Look at the figure shown below: A triangle RPQ is shown. S is a point on side PR and T is a point on side PQ. Points S and T are joined using a straight line. Nora is writing statements as shown to prove that if segment ST is parallel to segment RQ, then x = 45. Statement Reason 1. Segment ST is parallel to segment RQ Given 2. Angle QRS is congruent to angle TSP Corresponding angles formed by parallel lines and their transversal are congruent 3. Angle SPT is congruent to angle RPQ Reflexive property of angles 4. Triangle SPT is similar to triangle RPQ Angle-Angle Similarity Postulate 5. 60: (60+x) = Corresponding sides of similar triangles are in proportion Which of the following can she use to complete statement 5? a 60:(48 + 36) b 60:36 c 48:36 d 48:(48 + 36) Sudoku Company issues 7,000 shares of $7 par value common stock in exchange for land and a building. The land is valued at $45,000 and the building at $85,000. Prepare the journal entry to record issuance of the stock in exchange for the land and building. Flounder Corporation sells rock-climbing products and also operates an indoor climbing facility for climbing enthusiasts. During the last part of 2017, Flounder had the following transactions related to notes payable. Sept. 1 Issued a $14,400 note to Pippen to purchase inventory. The 3-month note payable bears interest of 8% and is due December 1. (Flounder uses a perpetual inventory system.) Sept. 30 Recorded accrued interest for the Pippen note. Oct. 1 Issued a $21,600, 8%, 4-month note to Prime Bank to finance the purchase of a new climbing wall for advanced climbers. The note is due February 1. Oct. 31 Recorded accrued interest for the Pippen note and the Prime Bank note. Nov. 1 Issued a $26,400 note and paid $8,900 cash to purchase a vehicle to transport clients to nearby climbing sites as part of a new series of climbing classes. This note bears interest of 7% and matures in 12 months. Nov. 30 Recorded accrued interest for the Pippen note, the Prime Bank note, and the vehicle note. Dec. 1 Paid principal and interest on the Pippen note. Dec. 31 Recorded accrued interest for the Prime Bank note and the vehicle note. a) Prepare journal entries for the transactions noted above. b) Post the above entries to the Notes Payable, Interest Payable, and Interest Expense accounts. c) Show the balance sheet presentation of notes payable and interest payable at December 31 d) How much interest expense relating to notes payable did Flounder incur during the year? interest expense incurred during the year: $ ? The volume of ammonia gas at 1.14 atm of pressure is gradually decreased from 90.3 mL to 43.4 mL. What is the final pressure of ammonia if there is no change in temperature state four causes of bribery and corruption in RME subject What is the range of the function? what is difference between vapourization and boiling point? show a quadrilateral ABCD in A is(2,8) and B is (8,6) .the point c lies on the perpendicular bisector of AB and the point D lies on the y- axis. the equation of BC is 3y=4x-14 and angle DAB=90 find(a) the equation of AD(b) the coordinates of D(c) the equation of perpendicular bisector of AB(d) the coordinates of Cshow the area of triangle ABC is 10 units and find the area of the quadrilateral ABCD Nuisance is something that A. Bothers you B. Can be dangerous C. Grows fast D. Is very small