Answers chapter 5 gas laws PDF

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Team Members: Gases Worksheet As usual, take turns reading each question and starting the discussion. 1. The picture to the left represents a sealed flask with a layer of water molecules in the liquid phase at the bottom under a layer of air saturated with water vapor. The flask at room temperature. Compose a list of the main differences between the liquid water and the water vapor. The liquid has the intermolecular bonds, that’s why the molecules stick. The gas has more KE.

A T = 273 K P = 1.0 atm V = 0.224 L

B T = 273 K P = 1.0 atm V = 0.224 L

C T = 273 K P = 2.0 atm V = 0.224 L

D T = 546 K P = 2.0 atm V = 0.224 L

E T = 273 K P = 2.0 atm V = 0.112 L

Figure 1 Representation of nitrogen and helium under different conditions. T is temperature, P is pressure, V is volume, and each or represents 1.0 x 1021 molecules. 1 atm = 760 mm Hg = 760 torr. 2. Label each flask as either N2 or He as appropriate. 3a. Compare flask A and flask B. How does the property of pressure change when the identity of the gas changes at a constant volume and constant temperature. Underline one: P is doubled P is halved P remains constant 3b. So according to question 3a, does the identity of the gas matter? No, it does not matter. 4. Compare flask A and flask C. How do the property of pressure change when the number of gas molecules double? Underline one: P is doubled P is halved P remains constant

5. Based on figure 1, between which flasks is the temperature doubled and the volume is constant? How does the pressure change when the temperature is doubled? A and D. The pressure doubles. 6. Based on figure 1, between which flasks is the volume doubled at a constant temperature and the same number of gas particles? What effect does doubling the volume have on the pressure? E and A. The volume is cut in half.

7. The symbol n is used to represent the number of moles. Circle the correct statements: P is proportional to n.

P is inversely proportional to n.

P is proportional to T.

P is inversely proportional to T.

P is proportional to V.

P is inversely proportional to V.

8. How many atoms of He are there in flask A? Show your work. 6 dots (1*1021 atoms/dot) = 6*1021 atoms 9. Using the number of atoms in flask A, calculate the number of moles (n). Avogadro’s number is 6.022 x 1023. Show your work of course! 6*1021 atoms (1 mol/6*1023 mol) = 0.1 mol

The ideal gas law: PV = nRT, where R is the universal gas constant. 10 Divide both sides of the ideal gas law by V and write the result. Is the ideal gas law consistent with your answers to question seven? P = nRT/V Yes.

11. Divide both sides of the ideal gas law by n and T to solve for R. Then use the values of P, T, n and V from container A to calculate R. Give the correct units. I haven’t done the math, the answer better be 0.0831 L(atm)/mol(K)

12. Repeat question 11 from one of the other flasks in figure 1. I haven’t done the math, the answer better be 0.0831 L(atm)/mol(K)

13. Are your answers to questions 11 and 12 the same? After your team comes to an agreement, explain why or why not.

14. Using the ideal gas law calculate the volume of 20.5 g of NH3 at 0.658 atm and 25° C. Recall that K = °C + 273. Convert the 20.5 g of NH3 to moles of NH3. Then plug that into PV = nRT. With P being 0.658 atm, and T being 298 K.

15. As a team reflect on your work so far. What is one way in which you are working well together as a team, and what is one way you can improve? Out line a strategy for improvement for the remainder of this activity.

The combined gas law. Rearranging the ideal gas law gives an equation that allow the calculation of the value one variable after the other two are changed. The subscripts define one condition or the other. 𝑃1 𝑉1 𝑃2 𝑉2 = 𝑇1 𝑇2 16. If T is held constant, how is the combined gas law changed? If T is constant then P1V1 = P2V2 This is Boyles law.

17. What is the effect on the volume of gas if you simultaneously double the pressure and double the Kelvin temperature? Doubling the pressure halves the volume, but doubling the temperature doubles the volume. So the nit is no change.

18. A sample of nitrogen gas has a volume of 3.5 L at 1.5 atm. If the temperature remains the same, what volume would the gas have if the pressure dropped to 0.30 atm? Ensure that all the team members agree.

3.5 L *1.5 atm = x L * 0.3 atm

x L = 3.5L(1.5 atm)/0.30 atm = 18 L

19. Did every one in your team understand the material in the activity today? If not, identify what your team needs to do to assure that everyone in the team understands the material in the next team activity. Adapted from Moog and Farrell. Chemistry: a guided inquiry. 6th ed., Wiley, 2015 and Garoutte and Mahoney. General, organic, and biological chemistry: a guided inquiry. 2nd ed., Wiley, 2014....