Chem. Final Exam (Sem.2 ) Review

What is the new pressure of 150 mL of a gas that is compressed to 50 mL when the original pressure was 3.0 atm and the temperature is held constant?

• 100 atm

• 0.90 atm

• 1.0 atm

• 9.0 atm

How many moles of Helium gas are present in 67.8L?

(1 mole = 22.4 L)

• 4 moles

• 10 moles

• 3.02 moles

• 13.6 moles

Calculate the approximate volume of a 1.50 mol sample of gas at 288K and a pressure of 3.75 atm. (R = 0.0821 L*atm/mol*K)

• 1.73 L

• 5.93 L

• 8.65 L

• 9.46 L

A tank that has a total pressure of 18.9 atm contains 3.6 atm of helium, 9.7 atm of argon, and an unknown amount of xenon. What is the partial pressure of xenon in the tank?

• 12.8 atm

• 13.3 atm

• 5.6 atm

• 6.1 atm

What would be the pH of a solution that has an [H+] concentration of 1 x 10^-4M?

• 0.9

• 1.0

• 4.0

• 10.0

What is the total pressure in a tank of gas that contains a mixture of oxygen, nitrogen, and hydrogen at 2.3atm, 4.5 atm, and 9.1atm respectively?

• 15.9 atm
• 3.7 atm
• 13.2 atm
• 10.1 atm

If a container holds 4.5 moles of oxygen gas at a volume of 45.7L and the volume is decreased to 37.1L, what is the new amount of moles?

• 6.7 moles
• 1.5 moles
• 8.3 moles
• 3.65 moles

What is the percent yield if in the lab 23.4 grams of magnesium chloride are collected, but theoretically 34.9 grams of magnesium chloride should have been collected?

• 149%
• 67.05%
• 35%
• 10%

How many moles are present in a solution of 2.3L with a concentration of 0.5M?

• 3.4 moles
• 1.15 moles
• 5.2 moles
• 1.9 moles

What is the concentration of [H+] of an acid with a pH of 4.6?

• 2.5x10^-5M
• 3.6x10^-4M
• 7.2x10^-9M
• 1.8x10^-3M