Answer:
146.5g/mol
Explanation:
The volume of gas effused is directly proportional to the square root of its relative molecular mass.
Let the volume of oxygen gas be V1
Let the volume of the unknown gas be V2
Let the molar mass of oxygen be M1
Let the molar mass of the unknown gas be M2
V1/V2 =√M2/M1
7.88/3.69 = √M2/32
2.14 = √M2/32
(2.14)^2 = M2/32
4.58 = M2/32
M2 = 32*4.58
M2 = 146.5g/mol
help! help! plz Why do two H atams combine to Form the molecule H2 while He remains monotonic?
How atoms interact with other atoms is largely dependant on the number of electrons on its outermost layer. The electrons on this layer are called valence electrons.
As you might know, atoms have their electrons arranged in layers/shells, starting at k, l m, n etc. Each layer has a maximum number of electrons it can accommodate, with the outermost one being the valence shell. The first layer (k) can accomodate 2 electrons, the second one (l) can accomodate 8, as can the third one (m) etc.
As a rule of thumb, most atoms don't like being alone. These atoms have a valence shell that isn't saturated. This is the case for hydrogen(1), with one free slot in its outter shell.
However, atoms like helium are a bit different. They are inert, and don't need to bond with other atoms. This is because their valence shell is saturated. In this case, helium saturated the k shell with 2 electrons. Helium in this form will not form bonds.
However, hydrogen is still out there looking for buddies. Hydrogen will bind with any other atom with a free electron. Being extremely common, it's likely that said atom will be another hydrogen.
However, another common example would be for 2 hydrogens to bond with one oxygen, forming h2O (oxygen can form 2 bonds)
Conclusion : helium is inert and will not interact with other atoms. Hydrogen is not, and thus needs to bond with other atoms.
For number 2 I need to find the molar mass, moles and give an empirical formula
4.2g of cerium reacted with oxygen to form 5.16g of an oxide of cerium. Find
the simplest formula of this oxide*
ASAP plz
Answer:
CeO₂
Explanation:
Hello!
In this case, since we are given the mass of both cerium and the cerium oxide, we can first compute the moles of cerium and the moles of oxygen as shown below:
[tex]n_{Ce}=4.2gCe*\frac{1molCe}{140.12gCe}=0.03molCe\\[/tex]
[tex]m_O=5.16g-4.2g=0.96gO\\\\n_O=0.96g*\frac{1molO}{16.0gO} =0.06molO[/tex]
Now, we simply divide each moles by 0.03 as the fewest moles in the formula to obtain the simplest formula (empirical formula) of this oxide:
[tex]Ce=\frac{0.03}{0.03}=1\\\\O =\frac{0.06}{0.03}=2[/tex]
Thus, the formula turns out:
[tex]CeO_2[/tex]
Regards!
Tris is a molecule that can be used to prepare buffers for biochemical experiments. It exists in two forms: Tris (a base) and TrisH (an acid). The MW of Tris base is 121.14 g/mol; the MW of TrisH is 157.6 g/mol (the extra weight is due to the Cl- counterion that is present in the acid). The Ka of the acid is 8.32 X 10-9. Assume that you have TrisH in solid form (a powder), unlimited 1M HCl, 1 M NaOH and distilled water. How would you prepare 1 L of a 0.02 M Tris Buffer, pH?
Solution :
For the reaction :
[tex]$\text{TrisH}^+ + H_2O \rightarrow \text{Trish}^- + H_3O^+$[/tex]
we have
[tex]$Ka = \frac{[\text{Tris}^- \times H_3O]}{\text{Tris}^+}$[/tex]
[tex]$=\frac{x^2}{0.02 -x}$[/tex]
[tex]$=8.32 \times 10^{-9}$[/tex]
Clearing [tex]$x$[/tex], we have [tex]$x = 1.29 \times 10^{-5} \text{ moles of acid}$[/tex]
So to reach [tex]$\text{pH} = 7.8 (\text{pOH}= 14-7.8=6.2)$[/tex], one must have the [tex]$\text{OH}^-$[/tex] concentration of the :
[tex]$\text{[OH}^-]=10^{-pOH} = 6.31 \times 10^{-7} \text{ moles of base}$[/tex]
So we can add enough of 1 M NaOH in order to neutralize the acid that is calculated above and also adding the calculated base.
[tex]$\text {n NaOH}=1.29 \times 10^{-5}+6.31 \times 10^{-7}$[/tex]
[tex]$= 1.35 \times 10^{-5} \text{ moles}$[/tex]
Volume NaOH [tex]$= 1.35 \times 10^{-5} \text{ moles} \times \frac{1000 \text{ mL}}{1 \text{ mol}} = 0.0135 \text{ mL}$[/tex]
Tris mass [tex]$H^+ = 0.02 \text{ mol} \times 157.6 \text{ g/mol}=3.152 \text{ g}$[/tex]
Now to prepare the said solution we must mix:
[tex]$3.152 \text{ g Tris H} + 0.0135 \text{ mL NaOH} \ 1 M$[/tex] gauge to 1000 mL with water.
1. Convert each of the following Celsius temperatures to Kelvin. a) 27°C b) 100°C c) 0°C
Answer:
a) 300K
b) 373K
c) 273K
Explanation:
to go from °C to K all you have to do is add 273.
Which is an appropriate layering process for a compost pile?
O a layer of pine needles, a layer of paper napkins, some soil, and some water
O a layer of paper napkins, a layer of grass clippings, some soil, and some water
O a layer of dried leaves, a layer of cheese, some soil, and some water
O a layer of grass clippings, a layer of fruit scraps, some soil, and some water
Answer: O a layer of grass clippings, a layer of fruit scraps, some soil, and some water
Explanation:
The compost pile is made up of decomposing organic materials that are obtained from dead and decaying vegetable or plant matter, animal materials like dung, dead skins and others. The decomposition is done by the soil microbes that recycle the matter into nutrients that are absorbed by the plants. All the components of the compost pile are degradable and completely converted into organic matter. The grass clipping and fruit scraps mixed with soil and water can be easily decomposed by the soil microbes easily.
The appropriate layering process for a compost pile would be: a layer of grass clippings, a layer of fruit scraps, some soil, and some water and the correct option is option 4.
This layering process ensures a balanced mix of nitrogen-rich "green" materials (such as grass clippings) and carbon-rich "brown" materials (such as fruit scraps).
The addition of soil introduces microorganisms necessary for decomposition, and water provides moisture for the composting process.
The layering of different materials promotes proper airflow and creates an optimal environment for the decomposition of organic matter, resulting in the formation of nutrient-rich compost.
Thus, the ideal selection is option 4.
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Question 6 of 10
Which law of motion states that an object's acceleration is directly related to
the net force applied and inversely related to the mass of the object?
O A. Newton's law of inertia
O B. Newton's second law
Ο Ο Ο
C. Newton's third law
OD. Newton's first law
Intermolecular forces exist between what?
Answer:
Intramolecular forces are the forces that hold atoms together within a molecule. Intermolecular forces are forces that exist between molecules.
Explanation:
A gas exerts a pressure of 4.1 atm at 300K. What is the pressure of the gas at 1010K?
Answer: 10
Explanation: 10 + 4.1 = 10
A gas exerts a pressure of 4.1 atm at 300K. Therefore, 13.1 atm is the pressure of the gas at 1010K.
What is pressure?The force delivered perpendicularly to an object's surface per unit volume over which this force is dispersed is known as pressure. The pressure as compared to the surrounding air is known as gauge pressure.
Pressure is expressed using a variety of units. Some of these come from dividing a unit of force by an area unit the traditional pressure measurement with in imperial and U.S. is the pound-force every square inch, whereas the SI pressure measurement, also called the pascal, becomes a newton per square meter.
P₁/T₁=P₂/T₂
4.1/300=P₂/1010
P₂ =13.1 atm
Therefore, 13.1 atm is the pressure of the gas at 1010K.
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How many joules of heat energy are absorbed when 80.0 g of water are heated from 10.0°C to 50.0°C? *
Answer:
13440 J
Explanation:
c ≈ 4200 J / (kg * °C)
m = 80 g = 0,08 kg
[tex]t_{1}[/tex] = 10 °C
[tex]t_{2}[/tex] = 50 °C
The formula is: Q = c * m * ([tex]t_{2} - t_{1}[/tex])
Calculating:
Q = 4200 * 0,08 * (50 - 10) = 13440 (J)
Some major contributions to the development of atomic theory are listed. Identify the scientist associated with each contribution. Not all names will be used, and some names will be used more than once. He discovered the electron. He discovered periodic changes in properties of elements when they are listed in order of their atomic weights. He experimented with the deflection of cathode rays by a magnetic field. He carried out experiments that measured the scattering of alpha particles by heavy atoms. His model of the hydrogen atom led to an accurate calculation of the wavelengths of light emitted by an excited hydrogen atom. He proposed the planetary model of the atom with most of the mass of the atom concentrated in a very small nucleus. He modified the planetary model of the atom by suggesting electrons could travel about the nucleus in only a few discrete stable orbits. Answer Bank
Answer:
He discovered the electron - J.J Thompson
He discovered periodic changes in properties of elements when they are listed in order of their atomic weights - Dimitri Mendeleev
He experimented with the deflection of cathode rays by a magnetic field - J.J Thompson
He carried out experiments that measured the scattering of alpha particles by heavy atoms - Ernest Rutherford
His model of the hydrogen atom led to an accurate calculation of the wavelengths of light emitted by an excited hydrogen atom - Neil Bohr
He proposed the planetary model of the atom with most of the mass of the atom concentrated in a very small nucleus - Ernest Rutherford
He modified the planetary model of the atom by suggesting electrons could travel about the nucleus in only a few discrete stable orbits - Neil Bohr
Explanation:
J.J Thompson discovered the electrons. He initially called them cathode rays and he also studied how they are deflected in magnetic fields and by so doing established that they are negatively charged particles.
Ernest Rutherford is renowned for his experiment using the thin gold foil and alpha particles to determine that atoms have a positively charged massive core called the nucleus. This led to the proposition of the planetary model of the atom.
Dimitri Mendeleev discovered periodic changes in properties of elements when they are listed in order of their atomic weights. This led to the discovery of the Mendeleev periodic table.
Neil Bohr model of the atom gave accurate explanation of the emission spectra of the hydrogen atom. His atomic model suggested that electrons could travel about the nucleus in only a few discrete stable orbits.
Answer:
He discovered the electron - J.J Thompson
He discovered periodic changes in properties of elements when they are listed in order of their atomic weights - Dimitri Mendeleev
He experimented with the deflection of cathode rays by a magnetic field - J.J Thompson
He carried out experiments that measured the scattering of alpha particles by heavy atoms - Ernest Rutherford
His model of the hydrogen atom led to an accurate calculation of the wavelengths of light emitted by an excited hydrogen atom - Neil Bohr
He proposed the planetary model of the atom with most of the mass of the atom concentrated in a very small nucleus - Ernest Rutherford
He modified the planetary model of the atom by suggesting electrons could travel about the nucleus in only a few discrete stable orbits - Neil Bohr
Explanation:
For the following reaction, 5.20 grams of propane (C3H8) are allowed to react with 22.5 grams of oxygen gas. propane (C3H8) (g) oxygen (g) carbon dioxide (g) water (g) What is the maximum amount of carbon dioxide that can be formed
Answer:
15.58g of CO₂ is the maximum amount that can be produced
Explanation:
The propane reacts with oxygen as follows:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Where 1 mole of propane reacts with 5 moles of oxygen
To solve this question we need to find the moles of propane and oxygen to find limiting reactant using the chemical reaction:
Moles propane -Molar mass: 44.1g/mol-:
5.20g * (1mol / 44.1g) = 0.118 moles
Moles oxygen -Molar mass: 32g/mol-:
22.5g O₂ * (1mol / 32g) = 0.703 moles
For a complete reaction of 0.703 moles of oxygen are:
0.703 moles O₂ * (1mol C₃H₈ / 5mol O₂) = 0.141 moles of propane are necessaries. As there are just 0.118 moles of propane, propane is limiting reactant.
The moles of carbon dioxide that are produced are:
0.118 moles C₃H₈ * (3 moles CO₂ / 1 mol C₃H₈) = 0.354 moles CO₂
The maximum mass that can be produced is -Molar mass CO₂: 44.01g/mol-:
0.354 moles CO₂ * (44.01g / mol) =
15.58g of CO₂ is the maximum amount that can be produced
double displacement reaction - write the balanced conventional, total ionic and net ionic equations:
Ca I2 (aq) + K2 C2 O4 (aq) >
Answer:
See explanation.
Explanation:
Hello!
In this case, these three equations show how the molecule behaves in terms aqueous and solid species; thus, we first write balanced conventional equation:
[tex]Ca I_2 (aq) + K_2 C_2 O_4 (aq)\rightarrow CaC_2O_4(s)+2KI(aq)[/tex]
Whereas the solid product is CaC₂O₄ based off its low solubility. Next, we ionize the aqueous species to obtain the total ionic equation:
[tex]Ca^{2+} +2I^- + 2K^+ +(C_2 O_4)^{2-} \rightarrow CaC_2O_4(s)+2I^- + 2K^+[/tex]
Finally, we cancel out potassium and iodide ions as they are the spectator ions due to their presence at both reactants and products in order to obtain the net ionic equation:
[tex]Ca^{2+} (aq) +(C_2 O_4)^{2-}(aq) \rightarrow CaC_2O_4(s)[/tex]
Best regards!
Can someone help me with this? And provide an explanation on how they found their answer? Using conversion factors. I'm confused :(
You have used 3.0×102 L of distilled water for a dialysis patient. How many gallons of water is that?
Answer:
This would be 63 gallons :)
Explanation:
The Volume of water = 2.4 × 10² L
The Volume of water in gal = ?
The solution: We know that one gal is equal to 3.785 litter.
So in conclusion, 2.4 × 10²L × 1 gal / 3.785 L
2.4 × 10²L × 0.264 gal. L⁻¹
0.634 × 10² gal
Hopefully this helps :3
63 gal
You have a 5M stock solution of NaCl (Formula Weight: 58.44g/mole), a 0.25M stock solution of glucose (Formula Weight; 180.156g/mole), and a bottle of solid Tris base (Formula Weight: 121.1g/mole). How would prepare (be specific) 250mL of a single solution containing 150mM Tris, 25mM glucose, and 150mM NaCl. g
Answer:
4.54g of Tris base,25mL of the 0.25M stock solution of glucose and 7.5mL of the 5M stock solution of NaCl must be added and complete the volume in a volumetric flask to 250.0mL
Explanation:
To prepare the single solution we need to find the moles of each solute (Tris, glucose and NaCl) from the stock solutions anf the solid:
Moles Tris:
0.250L *(0.150mol / L) = 0.0375moles Tris * (121.1g/mol) = 4.54g of Tris base must be added
Moles glucose:
0.250L * (0.025mol/L) = 6.25x10⁻³mol glucose * (1L / 0.25mol) = 0.025L = 25mL of the 0.25M stock solution of glucose must be added
Moles NaCl:
0.250L * (0.150mol / L) = 0.0375mol NaCl * (1L / 5mol) = 0.0075L =
7.5mL of the 5M stock solution of NaCl
You must add:
4.54g of Tris base,25mL of the 0.25M stock solution of glucose and 7.5mL of the 5M stock solution of NaCl must be added and complete the volume in a volumetric flask to 250.0mL
What heats the mantle?
Answer:
Fire
Explanation:
In a lab, silver nitrate,AgNO3, is dissolved in water until no solid is observed in the container. Then, a solution of sodium chloride, NaCl, is added to the container. When you combine these aqueous solutions, there is no noticeable change in temperature; however, a solid precipitates and there is a slight change of color. Which statements about the lab experiment involving silver nitrate and a sodium chloride solution are true?
Answer:
Formation of a solid indicates a chemical reaction occurred.
True
Explanation:
A chemical reaction is said to have occurred when a new substance(s) is (are) formed.
When we mix the sodium nitrate and sodium chloride, the following chemical reaction occurs;
2AgNO3(aq) + 2NaCl(aq) ------> 2AgCl(s) + 2NaNO3(aq)
The appearance of a solid shows that a chemical reaction has occurred and that NaCl really reacted chemically with AgNO3.
What is Molecule made off?
a) Electrons
b) Protons
c) Atoms
d) Nuclei
Answer:
C) Atoms
Explanation:
Hope that helped :)
someone help. trying to past this test but keep failing on this question.
Atoms may emit light energy when____
a. protons move to a higher energy level
b. protons move to a lower energy level
c. electrons move to a higher energy level
d. electrons move to a lower energy level
Answer:
When electrons move to a lower energy level.
Explanation:
When 9.00 g C6H12O6 burns with excess oxygen, how many grams
of CO2 will be made?
- 0.44 g
- 6.6 g
- 2.2 g
- 13.2 g
Five kilograms of liquid carbon tetrachloride undergo a mechanically reversible, isobaric change of state at 1 bar during which the temperature changes from 0∘C to 20∘C0 ∘ C to 20 ∘ C Determine ΔVt,W,Q,ΔHt, and ΔUt.ΔV t ,W,Q,ΔH t , and ΔU t . The properties for liquid carbon tetrachloride at 1 bar and 0∘C0 ∘ C may be assumed independent of temperature: β=1.2×10−3K−1,CP=0.84kJ⋅kg−1⋅K−1, and rho=1590kg⋅m−3β=1.2×10 −3 K −1 ,C P =0.84kJ⋅kg −1 ⋅K −1 , and rho=1590kg⋅m −3
Answer:
Explanation:
From the information given:
Mass of carbon tetrachloride = 5 kg
Pressure = 1 bar
The given density for carbon tetrachloride = 1590 kg/m³
The specific heat of carbon tetrachloride = 0.84 kJ/kg K
From the composition, the initial volume of carbon tetrachloride will be:[tex]= \dfrac{5 \ kg }{1590 \ kg/m^3}[/tex]
= 0.0031 m³
Suppose [tex]\beta[/tex] is independent of temperature while pressure is constant;
Then:
The change in volume can be expressed as:
[tex]\int ^{V_2}_{V_1} \dfrac{dV}{V} =\int ^{T_2}_{T_1} \beta dT[/tex]
[tex]In ( \dfrac{V_2}{V_1}) = \beta (T_2-T_1)[/tex]
[tex]V_2 = V_1 \times exp (\beta (T_2-T_1))[/tex]
[tex]V_2 = 0.0031 \ m^3 \times exp (1.2 \times 10^{-3} \times 20)[/tex]
[tex]V_2 = 0.003175 \ m^3[/tex]
However; the workdone = -PdV
[tex]W = -1.01 \times 10^5 \ Pa \times ( 0.003175 m^3 - 0.0031 \ m^3)[/tex]
W = - 7.6 J
The heat energy Q = Δ h
[tex]Q = mC_p(T_2-T_1)[/tex]
[tex]Q = 5 kg \times 0.84 \ kJ/kg^0 C \times 20[/tex]
Q = 84 kJ
The internal energy is calculated by using the 1st law of thermodynamics; which can be expressed as;
ΔU = ΔQ + W
ΔU = 84 kJ + ( -7.6 × 10⁻³ kJ)
ΔU = 83.992 kJ
Which mission is not going to explore outside of the solar system?
A. SAFIR
B. Europa Clipper
C. MIRI
D. Kepler
Strontium chlorate is mixed with ammonium phosphate
Explanation:
Please, if I may ask, what is the exact question?
9. ______________ Consists of the Sun and everything that orbits the Sun
10. ______________ A celestial body that orbits a star
11. ______________ The force that pulls all objects with mass toward one another
12. ______________ Located between the orbits of Mars and Jupiter
Answer:
9.solar system
10.comet
11.gravity
12.earth and saturn
Position vs Time
The starting position of this object is _______ m.
The object is traveling at a velocity of _______ m/s.
Answer:
The starting position of this object is 3 m.
The object is traveling at a velocity of 3 m/s
Explanation:
the graph begins at 3, and increases by 3 at each second
plz mark me brainliest. :)
How many significant figures
are in this number?
3 x 10^6
Practice Problem Website: https://www3.nd.edu/~smithgrp/structure/workbook.html
1. Click on Do the problems
2. Click on the number for the practice problem to be completed
3. Click on IR
Example of problem 1 from the website:
Formula: C3H5BrO2
IR Peaks:
1717 nm—Strong peak indicates a carbonyl group C=O
2571-2670 nm- medium peak indicates sp3 hybrid C-H.
3067 nm --- Broad medium peak indicates OH group, specifically in a carboxylic acid (Would not be a carboxylic acid without the carbonyl peak as well)
Complete the following problems: 3, 5, 7, 8, 12, 13, 27, 32, 38, and 40.
Be as accurate as possible. I am looking for the frequency and molecular formula to make sense with the functional group you think is represented.
Which distinguishes chemical changes from physical changes?
Answer:
In a chemical reaction, there is a change in the composition of the substances; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.
Explanation:
A 6.165 gram sample of an organic compound containing C, H and O is analyzed by combustion analysis and 10.27 grams of CO2 and 3.363 grams of H2O are produced. In a separate experiment, the molecular weight is found to be 132.1 amu. Determine the empirical formula and the molecular formula of the organic compound.
Answer:
Explanation:
mass of carbon in 10.27 g of CO₂ = 12 x 10.27 / 44 = 2.80 g
mass of hydrogen ( H ) in 3.363 g of H₂O = 2 x 3.363 / 18
= .373 g
These masses would have come from the sample of 6.165 g .
Rest of 6.165 g of sample is oxygen .
So oxygen in the sample = 6.165 - ( 2.8 + .373 ) = 2.992 g
Ratio of C , H , O in the sample
2.8 : .373 : 2.992
C: H : O : : 2.8 : .373 : 2.992
Ratio of moles
C: H : O : : 2.8/12 : .373/1 : 2.992 / 16
C: H : O : : .2333 : .373 : .187
C: H : O : : .2333/.187 : .373/.187 : .187/.187
C: H : O : : 1.247 : 1.99 : 1
C: H : O : : 5 : 8 : 4 ( after multiplying by 4 )
Hence empirical formula
C₅H₈O₄
Molecular formula ( C₅H₈O₄ )n
n ( 5 x 12 + 8 x 1 + 4 x 16 ) = 132
n x ( 60 + 8 + 64 ) = 132
n = 1
Molecular formula = C₅H₈O₄.
One mole (mol) of nitrogen monoxide (NO) has a mass of 30.01 g. When
precisely 2 moles of NO(g) are produced in the following chemical reaction, 43
kcal of heat energy is "absorbed."
N2(g) + O2(g) → 2 NO(g), AH = +43 kcal
How much heat (in kJ) is exchanged when 152 g of NO(g) is produced?
Answer:
455.6 kJ.
Explanation:
Hello there!
In this case, according to the given reaction, we know that 2 moles of NO require 43 kcal of energy, thus, for the energy required by 150 g of NO we first need the moles, considering its molar mass (30.01 g/mol):
[tex]152g*\frac{1mol}{30.01g} =5.065mol[/tex]
Thus, we apply the following dimensional analysis to obtain the energy absorbed by 5.065 moles:
[tex]5.065mol*\frac{43kcal}{2mol} =108.9kcal[/tex]
Which kJ turns out:
[tex]108.9kcal*\frac{4.184kJ}{1kcal}\\\\455.6kJ[/tex]
Best regards!