Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 48.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

40.g CaH2

Explanation:

1. ideal gas law(PV = nRT) → use ideal gas law first when volume is given

P = 0.995atm

V = 48.0L H2

n = ?

R = 0.0821L atm/molK

T = 32 + 273 = 305K

n = (0.995atm x 48.0L H2)/(0.0821L atm/molK x 305K) → do not simplify as small decimals might change the answer

2. Conversions

2 H2 and 1 CaH2 → 1/2

(mole of H2) x 1/2 x (molar mass of CaH2)

(0.995atm x 48.0L H2)/(0.0821L atm/molK x 305K) x 1/2 x (40.08 + 2.02) = 40.g CaH2

the longer answer will be 40.14887882 but as the minimum sigfig given in the question is 2, it is 40.g CaH2.

Hope it helped!

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

what does the table look like