Question

4. What is the mass of N2H4 gas in a 350.0 mL container at 50.0 °C, if the pressure of the gas is

885.0 torr?

Answer 1

0.36g

Step-by-step explanation:

Given parameters:

Volume of N₂H₄ = 350mL = 0.35dm³

Temperature of container = 50°C = 50 + 273 = 323K

Pressure = 885torr;

760torr = 1atm

885torr =
`(760)/(885)` = 0.86atm

Unknown:

Mass of the compound = ?

Solution:

The mass of the compound can be derived using the expression below;

Mass = number of moles x molar mass

molar mass of N₂H₄ = 2(14) + 4(1) = 32g/mol

To find the number of moles;

PV = nRT

n =
`(PV)/(RT)`

P is the pressure

V is the volume

R is the gas constant = 0.082atmdm³mol⁻¹K⁻¹

T is the temperature

n =
`(0.86 x 0.35)/(0.082 x 323)` = 0.01mole

So,

Mass = 0.01 x 32 = 0.36g