If the empirical formula of a compound is CH2O what is a possible molecular formula for the compound?

A C2H4O2
B CH20
C C5H705
D CH40

Kc = 0.040 for the system below at 450oc. if a reaction is initiated with 0.40 mole of cl2 and 0.40 mole of pcl3 in a 2.0 liter container, what is the equilibrium concentration of cl2 in the same system? pcl5(g) ⇄ pcl3(g) + cl2(g)

One does not belong why? ice, gold ,wood ,diamond and table salt

What substance has a mass of 9.5g and volume of 2.1cm^3