Question

Can someone please explain this chemistry question to me part a and part b please write neatly

a)You have a gaseous nitrogen (N2) system at a fixed temperature and pressure. If 25 grams occupies 0.125 liters, how much volume would 14 moles occupy?

b) You have a gaseous system with the following properties. Pressure = 725 mmHg Temperature = 27 °C Volume = 7.5 mL How many moles of gaseous particle do you have

Answer 1

a)

Molar mass of N2 = 28.02 g/mol

mass of N2 = 25 g

we have below equation to be used:

number of mol of N2,

n = mass of N2/molar mass of N2

=(25.0 g)/(28.02 g/mol)

= 0.8922 mol

we have:

V1 = 0.125 L

n1 = 0.8922 mol

n2 = 14 mol

we have below equation to be used:

V1/n1 = V2/n2

0.125 L / 0.8922 mol = V2 / 14 mol

V2 = 1.96 L

Answer: 1.96 L

b)

we have:

P = 725.0 mm Hg

= (725.0/760) atm

= 0.9539 atm

V = 7.5 mL

= (7.5/1000) L

= 0.0075 L

T = 27.0 oC

= (27.0+273) K

= 300 K

find number of moles using:

P * V = n*R*T

0.9539 atm * 0.0075 L = n * 0.0821 atm.L/mol.K * 300 K

n = 2.9*10^-4 mol

Answer: 2.9*10^-4 mol