How to determine the formula is you know g and l?

Agas has a volume of 0.7 l at 300 mmhg. what would be the new volume at 900 mmhg

What is the empirical formula of c6h18o3? ch3o c2h5o c2h6o c2h5o5

What causes different colors to appear in the sky? the absorption of light by air molecules the reflection of light by bodies of water the greenhouse effect in earth's atmosphere the scattering and reflection of light by dust particles