Unit 3 Midterm Review

Which of the following statements about state functions is true?

• The state functions associated with the ideal gas law are P, V, T, and R

• State functions are path dependent

• State functions describe quantitative values of a system at equilibrium

• As a system undergoes changes, the value of a state function must increase

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

A gas has a volume of 9.0 liters at a pressure of 1520 torr. If the pressure is decreased to 380 torr, what will be its new volume? (Assume the temperature remains constant)

• 2.3 liters

• 4.6 liters

• 0.28 liters

• 36 liters

A closed system with an initial pressure of 6 atm increases in volume from 5 liters to 10 liter while decreasing in temperature from 400 K to 200K. What is the new pressure of the system?

• 24 atm

• 1.5 atm

• 6 atm

• 3 atm

What is the molar mass of the gas that produces a pressure of 1 atm when 10 grams of the gas is added to a 12.5 L container at 300 K? Remember that at 300 K, RT is 25 l-atm

• 100 g/mol

• 10 g/mol

• 40 g/mol

• 20 g/mol

What is the volume of the system after reaction if 46 grams of ethanol (molar mass = 46
g/mole) reacts to completion with 96 grams of oxygen at STP? Assume all substances are in
the gas phase.
𝐶2𝐻5𝑂𝐻 + 3 𝑂2 → 2 𝐶𝑂2 + 3 𝐻2𝑂

• 200 liters

• 66 liters

• 134 liters

• 112 liters

Tags

NGSS.HS-PS1-7

At constant temperature, two different ideal gases have _____ average kinetic energies and they have _____

• different; the same diffusion rates

• the same; different average velocities

• different; the same average velocities

• he same; the same diffusion rates

The graph shows the Maxwell distribution plots for a given gas at three different temperatures.

Which plot corresponds to the highest temperature

• A

• B

• C

• Cannot be determined from this type of plot

Tags

NGSS.HS-PS3-2

Calculate the ratio of the rate of effusion of He to that of CO2 (at the same temperatures).

• √11: 1

• 1: 11²

• 11: 1

• 1: √11

Which of the following molecules would have the largest a and b terms, respectively, in the van der Waals equation?

Kr, CCl4, C2H4, C3H8, C4H10

• CCl4, C4H10

• C4H10, CCl4

• Kr, C3H8

• CCl4, CCl4

Given the equation: 2 NH3 (g) + 3 Cl2 (g) → N2 (g) + 6 HCl (g) How many Liters of nitrogen can be made from 10.0 L of chlorine gas at STP?

• 60.0 L

• 30.0 L

• 10.0 L

• 3.3 L

Tags

NGSS.HS-PS1-7