hydrates (1 question)

We are given:

half-life of carbon = 5715 years

Initial mass = 100 grams

Final mass = 12.5 grams

Finding the time taken:

Number of half-lives:

We know that in the relation:

[tex]\frac{Final\_mass}{Initial\_mass} = \frac{1}{2^{n}}[/tex], n is the number of half-lives taken

replacing the given values:

12.5 / 100 = 1/2ⁿ

1/8 = 1/2ⁿ

2ⁿ = 8

2ⁿ = 2³

n = 3

Hence, it took 3 half-lives to reduce the mass to 12.5 grams

Number of years:

Time taken = 3 half-lives

we know that one half-life is 5715 years, replacing that value:

Time taken = 3*(5715) years

Time taken = 17145 years

Therefore, after 17145 years, a 100 gram sample of carbon will decay and only 12.5 grams will remain

Answer:

9.42 g

Explanation:

Step 1: Write the balanced equation

2 Al + 3 Cl₂ ⇒ 2 AICI₃

Step 2: Calculate the moles corresponding to 11.727 L of Cl₂

Since the conditions are not specified, we will assume Cl₂ is at standard temperature and pressure. At STP, 1 mole of Cl₂ occupies 22.4 L.

11.727 L × 1 mol/22.4 L = 0.524 mol

Step 3: Calculate the moles of Al needed to react with 0.524 moles of Cl₂

The molar ratio of Al to Cl₂ is 2:3. The moles of Al needed are 2/3 × 0.524 mol = 0.349 mol

Step 4: Calculate the mass corresponding to 0.349 moles of Al

The molar mass of Al is 26.98 g/mol.

0.349 mol × 26.98 g/mol = 9.42 g

Answer:

THE RIGHT ONE IS THE NERVOUS SYSTEM

Explanation:

THE EXPLANATION IS THAT : The nervous system is the part of an animal's body that coordinates its behavior and transmits signals between different body areas. In vertebrates it consists of two main parts, called the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord.

Answer:

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Explanation:

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Answer:

1720.8g water are necessaries

Explanation:

Mass percent is defined as the mass of solute (In this case, MgCl2) in 100g of solution (Mass MgCl2 + Mass water). To solve this question we must find the mass of solution that we need to produce th 1.5% by mass solution. Thus, we can find the mass of water that we need as follows:

Mass solution:

26.2g MgCl2 * (100g Solution / 1.5g MgCl2) = 1747g solution

Mass water:

1747g solution - 26.2g MgCl2 = 1720.8g water are necessaries

Answer:

here's the answer.hope it helps

Answer: The molarity of this solution is 0.159 M.

Explanation:

Given: Mass of solute = 16.3 g

Volume = 1.75 L

Number of moles is defined as the mass of substance divided by its molar mass.

Hence, moles of NaCl (molar mass = 58.44 g/mol) ar calculated as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{16.3 g}{58.44 g/mol}\\= 0.278 mol[/tex]

Molarity is the number of moles of a substance present in a liter of solution.

So, molarity of the given solution is calculated as follows.

[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.278 mol}{1.75}\\= 0.159 M[/tex]

Thus, we can conclude that the molarity of this solution is 0.159 M.

Answer:

The pond has more energy because I is so much larger that the Cup of boiling water. Since that mass of the pond is so much larger, It is generating more energy than a boiling cup of water.

To solve this we must be knowing each and every concept related to hybridisation. Therefore, the hybridisation of the given molecule can be given as below.

Only during bond formation does hybridization occur, not in an individual gaseous atom. If the bonding of a molecule is known, the geometry of the molecule may be predicted.

compound                                                              hybridisation

Carbon dioxide (0 = C = O)                                       sp

Propene (CH[tex]_3[/tex]CH = CH[tex]_2[/tex])                                            sp³, sp²,sp²

Formaldehyde (H[tex]_2[/tex]C = O)                                             sp²

Acetone [(CH[tex]_3[/tex] )[tex]_2[/tex] C = O                                                 sp³, sp²,      sp³

Ketene (H[tex]_2[/tex]C = C = O)                                                  sp²,    sp

Therefore, the hybridisation of the given molecule can be given as above.

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Answer:

the movement of particles from a higher consentration to a lower consentration through a mechanical support.

Explanation:

Explanation:

5 lollipops = 6 gumballs

8 gumballs = 6 lemonheads

14 lemonheads = 11 lollipops

It is in chain rule form.

Answer:

야만적 인 사랑은 누군가가 천사처럼 보이지만 야만적 인 사랑은 당신의 마음을 부러 뜨리게했다너무 귀엽다

Explanation:

난 천사야 네가 무슨 뜻인지 말해줘나는 모든 것을 가지고 나는 그것을 다시 포기하지 않을 것이다

Answer:

255.46 grams NO3

Explanation:

The molar mass of NO3 is 62.0049 g/mol.

To get grams from moles, multiply the moles by the molar mass.

4.12*62.0049 = 255.4602 = 255.46 grams NO3

Answer:

no se englesh

ajajajaja

To find the density of the unknown piece of metal, we can use the formula:

Density = mass / volume.

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From the balanced equation of the reaction, the mole ratio of the reactants is 1:3.

Mole of 50.0 g [tex]Fe_2O_3[/tex] = 50/160 = 0.3125 mol

Mole of 10.0 g CO = 10/28 = 0.3571 mol

Stoichiometric equivalent of  [tex]Fe_2O_3[/tex] = 0.3571/3 = 0.1190 mol

In other words,  [tex]Fe_2O_3[/tex] is in excess.

Excess mole = 0.3125 - 0.1190 = 0.1935 mol

Mass of 0.1935 mol [tex]Fe_2O_3[/tex] = 0.1935 x 160 = 30.96 grams

Mole ratio of CO to Fe = 3:2

Equivalent mole of Fe that would be formed = 0.3571 x 2/3

                                                                          = 0.2381 mol

Mass of 0.238 mol Fe = 0.238 x 56 = 13.328 grams

Percent yield of Fe = 11.5/13.328 x 100 = 86.28%

Mole of 75 gk CO2 = 75000/44 = 1704.55 mol

Mole ratio of CO2 and Co = 1:1

Equivalent mole of CO = 1704.55 mol

Mass of 1704.55 mol CO = 1704.55 x 28 = 47.73 kg

80.7% = 47.73 kg

100% = 100 x 47.73/80.7

        = 59.14 kg

In other words, 59.14 kg of CO would be needed.

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Answer: The answer is B) 1.00 M CaCl2

Explanation: I just did it on usatestprep and it said it was correct .

Answer: The value of [tex]K_{c}[/tex] for the given reaction is  [tex]K_{c} = \frac{[HI]^{2}}{[H_{2}][I_{2}]}[/tex] .

Explanation:

The ratio of concentration of products and reactants raised to the power of their concentration is called equilibrium constant.

It is denoted by the symbol [tex]'K_{c}'[/tex].

For example, [tex]H_{2} + I_{2} \rightarrow 2HI[/tex]

The expression for [tex]K_{c}[/tex] of this reaction is as follows.

[tex]K_{c} = \frac{[HI]^{2}}{[H_{2}][I_{2}]}[/tex]

So, by putting the respective concentrations of the species involved in the reaction it is possible to determine the value of [tex]K_{c}[/tex] for the given reaction.

Thus, we can conclude that the value of [tex]K_{c}[/tex] for the given reaction is  [tex]K_{c} = \frac{[HI]^{2}}{[H_{2}][I_{2}]}[/tex] .

Answer:

They are 4 short column on the periodic table

Answer:

C: The products react to re-form the original reactants.

Explanation:

A reversible reaction is one where the conversion of reactants to products as well as the conversion of products to reactants happen at the same time.

What this means is that the products of the reaction could react to reform the initial reactants.

Thus, option C is the correct answer.

Answer:

C

Explanation:

The products react to re-form the original reactants.

Answer: The solubility product of AgCl is [tex]10.73 \times 10^{-9}[/tex].

Explanation:

The reaction equation is as follows.

[tex]Ag_{2}CO_{3} \rightleftharpoons 2Ag^{+} + CO^{2-}_{3}[/tex]

Let us assume the concentration of [tex]2Ag^{+}[/tex] is 2S and concentration of [tex]CO^{2-}_{3}[/tex] is S. Hence, the expression for [tex]K_{sp}[/tex] of this reaction is as follows.

[tex]K_{sp} = [Ag^{+}]^{2}[CO^{2-}_{3}]\\8.2 \times 10^{-12} = (2S)^{2}(S)\\8.2 \times 10^{-2} = 4S^{3}\\S = 1.27 \times 10^{-4}[/tex]

This means that [tex][Ag^{+}][/tex] is [tex]1.27 \times 10^{-4}[/tex]. Now, the concentration of [tex]Cl^{-}[/tex] is calculated as follows.

[tex][Cl^{-}] = \frac{mass}{molar mass}\\= \frac{0.003 g}{35.5 g/mol}\\= 8.45 \times 10^{-5} M[/tex]

Hence,  [tex]K_{sp}[/tex] for AgCl is calculated as follows.

[tex]K_{sp} = [Ag^{+}] \times [Cl^{-}]\\= 1.27 \times 10^{-4} \times 8.45 \times 10^{-5}\\= 10.73 \times 10^{-9}[/tex]

Thus, we can conclude that solubility product of AgCl is [tex]10.73 \times 10^{-9}[/tex].

Answer:

-533.68J

Explanation:

Using the formula as follows:

Q = m × c × ∆T

Where;

Q = amount of heat required (Joules)

m = mass of substance (g)

c = specific heat of substance (J/g°C)

∆T = change in temperature (°C)

According to the information provided in this question;

Q = ?

m = 28.3 g

c of iron = 0.449 J/g°C

∆T = 24°C - 66°C = -42°C

Using the formula, Q = m × c × ∆T

Q = 28.3 × 0.449 × (-42)

Q = -533.68

Q = -533.68J

This means that 533.68J is lost to the environment when iron of 28.3g cools from 66°C to 24°C.

Answer:   It takes 285.8 kJ of energy to form one mole of water

Explanation:

The enthalpy of formation of a substance is the change in enthalpy that occurs when a substance is formed from its elements in their standard states. The enthalpy of the formation of water is -285.8 kJ/mol, which means that it takes 285.8 kJ of energy to form one mole of water from its elements (hydrogen and oxygen) under standard conditions. This value is negative, which means that the formation of water releases energy. This is why water is often referred to as an "exothermic" substance because it releases energy when it is formed. The negative value of the enthalpy of formation for water can be explained by the fact that the bonds formed between hydrogen and oxygen atoms in water are stronger than the bonds between hydrogen and oxygen atoms in the individual elements. This means that it takes less energy to break the bonds in the elements than it releases when the bonds in water are formed, resulting in a net release of energy.

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Answer:

This means that 285.8 kJ/mol is evolved when one mole of water is formed.

What is the enthalpy of formation?

The term enthalpy of formation has to do with the energy that is released or absorbed when a molecule of water if formed from its constituents.

The fact that the enthalpy of formation of water is -285.8 kJ/mol implies that 285.8 kJ/mol is evolved when one mole of water is formed.

Explanation:

The relationship between the calculated concentration of a material and the actual concentration of particles is known as the Van't Hoff factor.

I is the difference between a typical or theoretical colligative quality and an observable one.

The van 't Hoff factor is the difference between the concentration of a material determined by its mass and the concentration of particles actually formed when the substance is dissolved. The van 't Hoff factor is virtually 1 for the majority of non-electrolytes dissolved in water.

For dissociation, association, and the non-electrolyte solute, the Van't Hoff factor value is more than one, less than one, and equal to one respectively.

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Answer:

a)  [tex]T_b=590.775k[/tex]

b)  [tex]W_t=1.08*10^4J[/tex]

d)  [tex]Q=3.778*10^4J[/tex]

d)  [tex]\triangle V=4.058*10^4J[/tex]

Explanation:

From the question we are told that:

Moles of N2 [tex]n=2.50[/tex]

Atmospheric pressure [tex]P=100atm[/tex]

Temperature [tex]t=20 \textdegree C[/tex]

                      [tex]t = 20+273[/tex]

                     [tex]t = 293k[/tex]

Initial heat [tex]Q=1.36 * 10^4 J[/tex]

a)

Generally the equation for change in temperature is mathematically given by

[tex]\triangle T=\frac{Q}{N*C_v}[/tex]

  Where

  [tex]C_v=Heat\ Capacity \approx 20.76 J/mol/K[/tex]

[tex]T_b-T_a=\frac{1.36 * 10^4 J}{2.5*20.76 }[/tex]

[tex]T_b-293k=297.775[/tex]

[tex]T_b=590.775k[/tex]

b)

Generally the equation for ideal gas is mathematically given by

 [tex]PV=nRT[/tex]

For v double

 [tex]T_c=2*590.775k[/tex]

 [tex]T_c=1181.55k[/tex]

Therefore

[tex]PV=Wbc[/tex]

[tex]Wbc=(2.20)(8.314)(1181_590.778)[/tex]

[tex]Wbc=10805.7J[/tex]

Total Work-done [tex]W_t[/tex]

[tex]W_t=Wab+Wbc[/tex]

[tex]W_t=0+1.08*10^4[/tex]

[tex]W_t=1.08*10^4J[/tex]

c)

Generally the equation for amount of heat added is mathematically given by

[tex]Q=nC_p\triangle T[/tex]

[tex]Q=2.20*2907*(1181.55-590.775)\\[/tex]

[tex]Q=3.778*10^4J[/tex]

d)

Generally the equation for change in internal energy of the gas is mathematically given by

[tex]\triangle V=nC_v \triangle T[/tex]

[tex]\triangle V=2.20*20.76*(1181.55-293)k[/tex]

[tex]\triangle V=4.058*10^4J[/tex]

Answer:

You didnt give me a molarity so ill show you how to solve it with an equation

Explanation:

Molarity represent by M

M= mols/ Volume (in liters)

so mols = (whatever the molarity was) x (.100L because it is =100ml)

Mols=  M x (.100)

plug in the molarity you have for x and you are done

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As depth increases, the density of the layers decreases.

The statement, that describes the thickness, top density, and bottom density of the different layers of the Earth is "as depth increases, the density of the layers decreases."

The density of the Earth's inner layers determines their order. The densest layer is the solid metal inner core, the mantle is of intermediate density, and the lithosphere, particularly the continental lithosphere, is the least dense layer.

Pressure rises as you go deeper. Mass/volume = density. As a result, as the volume drops, so does the density. Because of pressure, the strata beneath us become extremely dense. As a result, as the depth of the earth increases, so does the density.

Hence the correct answer is as depth increases, the density of the layers decreases.

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Answer:

B. potential energy

Explanation:

Potential energy ( Mechanical in this case ) is energy stored by force. so If you are compressing a spring you are increasing more potential to it by force.

Answer:

(E)

Explanation:

When aqueous solutions are added together, one of the products is s solid.