AP CHEMISTRY
Week 3 Problem Set
Solutions
, AP Chemistry Week 3
Problem Set Solution
Multiple Choice Questions
Question 1: How many mLs of 10.00 M HCl is needed to make 500mL of 2.00M HCl?
A) 1.00 mL
B) 10.0 mL
C) 20.0 mL
D) 100. mL
E) 200. mL
Answer: D, 100mL
𝐶" 𝑉" = 𝐶% 𝑉% 𝐶" = 10.00𝑀 𝐻𝐶𝑙
𝐶2𝑉2 2.00𝑀 × 0.500𝐿 𝑉" = ?
𝑉1 = = = 0.100𝐿 = 100𝑚𝐿
𝐶1 10.00𝑀
𝐶% = 2.00𝑀 𝐻𝐶𝑙
𝑉2 = 500𝑚𝐿 = 0.500𝐿
Question 2: Equal masses of He and Ne are placed in a sealed container. What is the
partial pressure of He if the total pressure in the container is 6 atm?
A) 1 atm
B) 2 atm
C) 3 atm
D) 4 atm
E) 5 atm
Answer: E, 5 atm
Assume gas mixture has 10g of He and 10g of Ne. According to Dalton’s Law of Partial
Pressure, the pressure of He equals to total pressure multiplied by the mole fraction of
He.
𝑚 1𝑚𝑜𝑙
𝑛45 = = 10𝑔 × = 2.5 𝑚𝑜𝑙 𝐻𝑒
𝑀𝑀 4𝑔
𝑚 1𝑚𝑜𝑙
𝑛:5 = = 10𝑔 × = 0.5 𝑚𝑜𝑙 𝑁𝑒
𝑀𝑀 20𝑔
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Week 3 Problem Set
Solutions
, AP Chemistry Week 3
Problem Set Solution
Multiple Choice Questions
Question 1: How many mLs of 10.00 M HCl is needed to make 500mL of 2.00M HCl?
A) 1.00 mL
B) 10.0 mL
C) 20.0 mL
D) 100. mL
E) 200. mL
Answer: D, 100mL
𝐶" 𝑉" = 𝐶% 𝑉% 𝐶" = 10.00𝑀 𝐻𝐶𝑙
𝐶2𝑉2 2.00𝑀 × 0.500𝐿 𝑉" = ?
𝑉1 = = = 0.100𝐿 = 100𝑚𝐿
𝐶1 10.00𝑀
𝐶% = 2.00𝑀 𝐻𝐶𝑙
𝑉2 = 500𝑚𝐿 = 0.500𝐿
Question 2: Equal masses of He and Ne are placed in a sealed container. What is the
partial pressure of He if the total pressure in the container is 6 atm?
A) 1 atm
B) 2 atm
C) 3 atm
D) 4 atm
E) 5 atm
Answer: E, 5 atm
Assume gas mixture has 10g of He and 10g of Ne. According to Dalton’s Law of Partial
Pressure, the pressure of He equals to total pressure multiplied by the mole fraction of
He.
𝑚 1𝑚𝑜𝑙
𝑛45 = = 10𝑔 × = 2.5 𝑚𝑜𝑙 𝐻𝑒
𝑀𝑀 4𝑔
𝑚 1𝑚𝑜𝑙
𝑛:5 = = 10𝑔 × = 0.5 𝑚𝑜𝑙 𝑁𝑒
𝑀𝑀 20𝑔
02
