Question

What volume of nitrogen gas at STP can form from 1.20 mol NaN3?
2NaN3(s) 2Na(s) + 3N2(g)

A. 40.3 L
B. 1.20 L
C. 13.4 L
D. 1.80 L

Answer 1

You can convert any mol in this equation to any other mol in this equation by using the coefficients in the balanced equation.

For example:
How many mols NaN3 are necessary to obtain 10 mols Na?

10 mols Na x (2 mols NaN3/2 mols Na) = 10 x 2/2 = 10.
The number on the top of the fraction is ALWAYS the coefficient of what you want to convert TO and the number on the bottom of the fraction is ALWAYS the coefficient of what you HAVE.

Answer 2

Ok so with 1.2 mols of NaN3 you have 1.8 mols of nitrogen gas. How do I convert it to liters?

Answer 3

You remember that 1 mol of a gas at STP occupies 22.4 L.

Answer 4

The answer is 40.3

Answer 5

R, universal gas constant is 8.314 J/ Kmole or 0.0821 L atm/K mol.
in this case, apply 0.0821 for R since we are using liter and atm.
If you calculate it right, it will give 40.3 L