# Change in moles

1. Nov 21, 2004

### mikep

An automobile tire has a volume of $$0.0185 m^3$$. At a temperature of 294 K the absolute pressure in the tire is 241 kPa. How many moles of air must be pumped into the tire to increase its pressure to 252 kPa, given that the temperature and volume of the tire remain constant?

can someone please if i'm doing this correctly?

PV = nRT
$$(241000 N/m^2)(0.0185 m^3) = n (8.3J/K*mole)(294K)$$
n = 1.83

$$(252000 N/m^2)(0.0185 m^3) = n (8.3J/K*mole)(294K)$$
n = 1.91
1.91 - 1.83 = 0.08

2. Nov 21, 2004

### vsage

Looks ok to me.