# chemistry

posted by
**me**
.

i reallly need help with combining the gas laws. here are a few questions i am struggling with if anyone could please help!

1. A steel container holds 750.L of O2 gas at STP.

a) how many moles of O2 does the container hold?

b)how many grams of O2 does the container hold?

c) if the pressure were reduced by removal of gas until it was 380.mm Hg, what mass of tha gas would remain in the tank?

2. Given 100.mL of a gas at 22 degrees celcius and 380 mm Hg, what would the volume be at STP?

3. The volume of a dry gas originally at STP was recorded as 488.8mL. What volume would the same gas occupy when subjected to a pressure of 1.00 x 10^4 kPa and temperature of -245 degrees celcius.

4. the mass of 15.0 mL of a gas at 500. kPa of pressure and a temperature of -53 degrees celcius is 8.35 x 10^-3g.

a) what is the density of this gas at these conditions?

b) what is the density of this gas at STP conditions?