5.If there are 6.25 L of Hydrogen gas at a pressure of 1.95 ATM and a temperature of 243 K, how many grams of

Answer 1

Your question is incomplete, so I will guess that you are wanting to know the number of grams of hydrogen gas. If so, then we start with the general gas equation (my personal favourite - it solves all your problems - but I digress):

PV = nRT
where
P = pressure
V = volume
n = number of moles
T = temperature (absolute)

Substituting into the above gives:
1.95 x 6.25 = n x 0.0821 x 243

Solve for n, then determine mass of hydrogen by multiplying the number of moles by the molecular mass of H2. I get 1.22 g. I trust that helps.