Question

1.

Which of the following statements about nitrogen gas is incorrect ?

Select one:

a. it expands when its temperature is increased at constant pressure

b. the distance between particles is about the same as for liquids

c. the pressure is proportional to the concentration of particles present

d. it expands to fill its container

e. it is less dense than iron

2.

What is the minimum volume of 0.1060 M AgNO₃ that must be reacted with 100.0 mL of 0.0862 M K₂CrO₄ to precipitate all the chromate ions as Ag₂CrO₄?

Select one:

a. 203 mL

b. 163 mL

c. 175 mL

d. 81.3 mL

e. 50.8 mL

3.

What is the pressure of 0.4 moles of gas inside a sealed 5.2 L container at 350 K?

Select one:

a. 22 atm

b. 224 atm

c. 2.2 atm

d. 6052 atm

e. 60 atm

4.

What is the mass % of silver fluoride in a solution prepared by mixing 50.0 g of a 15.0 mass % silver fluoride solution with 23.0 g of an 11.9 mass % silver fluoride solution?

Select one:

a. 20.5%

b. 14.7%

c. 10.2%

d. 13.5%

e. 14.0%

Answer 1

1. Which of the following statements about nitrogen gas is incorrect ?

b. the distance between particles is about the same as for liquids

Reason: In gases the N2 molecules are lossely packed. When it is compressed to liquid the the distance between the molcules decreases. So the distances are not same in liquid and gas.

2) What is the minimum volume of 0.1060 M AgNO3 that must be reacted with 100.0 mL of 0.0862 M K2CrO4 to precipitate all the chromate ions as Ag2CrO4?

2AgNO₃ + K₂CrO₄ ------------> Ag₂CrO₄ + 2KNO₃

Moles of K₂CrO4 present in the solution = Molarityxvolume = 0.0862 M x 0.100 L =

Moles of AgNO₃ needed =

=0.01724 mol AgNO₃

b) Volume of AgNO₃ = 0.163 L =163 mL

3.

Moles of gas=n = 0.4 mol

Volume = V=5.2 L

Temperature = T = 350 K

R=0.0821 L.atm/mol.K

Pressure = PV=nRT

C) P = 2.2 atm

4.

Let there be two solution A and B

Percentage of AgF in A solution = 15.0 %

Mass of AgF in solution A = 50.0g

Percentage of AgF in solution B = 11.9%

Mass of AgF in B = 23.0 g

Mass of AgF in solution by mixing A and B = 50.0 + 23.0 g = 73.0 g

Percentage of AgF in mixing from A =

Percentage contribtion of AgF from A =10.3%

Percentage of AgF from B =

Percentage contribtion of AgF from B =3.7%

e) Total percentage contribution of AgF = 10.3 + 3.7 = 14.0%