Hydrazine and H2O2 reaction help

Question

Hydrazine and H2O2 react to produce nitrogen gas and water. How many grams of H2O2 needed to react with 100 grams of hydrazine?

Answer 1

first balance the equation

NH2NH2 +  2H2O2------ N2 + 4 H2O

so NH2NH2 reacts with H2O2 in a 1:2 molar ratio

so 100 grams of hydrazine = 100/32grams/mole = 3.125 moles of hydrazine   so given that 1 mole of hydrazine reacts with 2 moles of hydrogen peroxide then one will need 2 X 3.125 moles of H2O2 = 212.5 grams of H2O2.

Proof    

32 grams of hydrazine react with 2 ( 34 ) = 68 grams of H2O2

soo 32/68= 100/X   solving for X = 212.5 grams of H2O2

Answer 2

Moles of Hydrazine = 100.0 g / 32 g/mol = 3.12

The ratio between Hydrazine and H2O2 is 1 : 2

Moles H2O2 needed = 2 x 3.12 = 6.24

Mass H2O2 = 6.24 x 34.01 g/mol = 212.2 g