Question

The molar mass of NH3 is 17.03 g/mol. The molar mass of H2 is 2.0158 g/mol. In a particular reaction, 0.575 g of NH3 forms. What is the mass, in grams, of H2 that must have reacted, to the correct number of significant figures?

Answer 1

0.102

Step-by-step explanation:

Answer 2

the answer
the general for of the equation of reaction is
N2 + 3 H2 ------------ 2NH3
1mol 3mole 2 mole
nH2 nNH3
(nX means number of mole of X)

according to the law of proportion
3 / nH2 = 2 / nNH3 (E)

nNH3 = m NH3 / 17.03 , and m NH3 = 0.575 g
consequently nNH3 = 0.575 g / 17.03 = 0.03 mol

by considering (E) 3 / nH2 = 2 / 0.03 = 66.66, and nH2 = 3 / 66.66 =0.045

finally we can write

mH2 = nH2 x 2.0158 =0.045 x 2.0158 = 0.09 g