Question

0.1212 grams of dry gas occupies a volume of 65.7 ml at 10ºC and

740 mm pressure. Calculate the molecular weight of the gas.​

Answer 1

Answer:

44.88g/mol

Explanation:

we need to use, PV = nRT

units should be in SI form, so, let's get started,

P = 740mm Hg = 98658.55Pa

V = 65.7ml = 6.57x10^-5 m3

n = ?

R = 8.314 J.K-1.mol-1

T = 10 °C = 283.15 °K

now put the values in above Equation, before that, rearrange the equation to find n,

n = PV/RT

now put the values,

n = (98658.55 * 6.57x10^-5)/(8.314*283.15)

n = 6.4819/2354.11

n = 0.0027

we know that,

moles (n) = weight (w) / molecular weight (M)

we need to find molecular weight, hence,

molecular weight M = w/n

w is given = 0.1212g

M = 0.1212/0.0027

M = 44.88g/mol