Question

PART A A sample of 0.030 grams of magnesium is reacted with excess HCl at 25°C and 1.00 atm. The resulting gas is collected over water using an inverted buret. Will the student need to use a 25.00 mL or a 50.00 mL buret in this experiment?

PART B A sample of helium and neon gas occupy 1.50 L container at 45.0ºC. Calculate the partial pressure of each gas if the total pressure is 1.55 atm and the mole fraction of neon is 0.75.

PART C A 65.0 g sample of solid sodium is reacted with water to produce sodium hydroxide and hydrogen gas. What volume (in mL) of hydrogen gas is produced at 25.5ºC and 1.20 atm?

Answer 1

part A and B are done using ideal gas equation , pV = nRT

gas constant ,R = 0.0821lit.atm/k.mol

T = 273 +temperature in degree celsius

2) partial pressure of the gas in the mixture= total pressure of the mixture x mole fraction of the component

sum of mole fractions of components in the mixture = unity ,1 always

mole fraction of helium = 1- mole fraction of neon

= 1- 0.75

= 0.25

partial pressure of the neon in the mixture = 1.55 atm x 0.75

= 1.1625 atm

partial pressure of the helium in the mixture = 1.55 atm x 0.25

= 0.3875 atm