Question

What is the volume, in liters, of 6.8 mol of Kr gas at STP?

Answer 1

Answer:

$\boxed {\boxed {\sf D. \ 152 \ L}}$

Explanation:

Any gas at standard temperature and pressure (STP) has a volume of 22.4 liters per mole or 22.4 L/mol. We can create a proportion with this value.

$\frac {22.4 \ L \ Kr}{1 \ mol \ Kr}$

Multiply both sides of the equation by 6.8 moles of krypton.

$6.8 \ mol \ Kr *\frac {22.4 \ L \ Kr}{1 \ mol \ Kr}$

The units of moles of krypton will cancel.

$6.8 *\frac {22.4 \ L \ Kr}{1 }$

The denominator of 1 can be ignored, so this becomes a simple multiplication problem.

$68 * 22.4 \ L \ Kr$

$152.32 \ L \ Kr$

If we round to the nearest whole number, the 3 in the tenths place tells us to leave the 2 in the ones place.

$152 \ L \ Kr$

6.8 moles of krypton gas at standard temperature and pressure is equal to 152 liters.