Question

which of the following correctly gives the best coefficients for the reaction below? n2h4 (g)+ h2o2 (g) → n2 (g) + h2o(g)
a 0,2,4,2,8
b a)1,1,1,1
c b)1,2,1,4
d d)1,4,1,4

Explanation:

Step1: Balance nitrogen atoms

The reactant $N_2H_4$ has 2 nitrogen atoms and the product $N_2$ has 2 nitrogen atoms. So, the coefficient of $N_2H_4$ and $N_2$ can be 1 for nitrogen - atom balance.

Step2: Balance hydrogen atoms

$N_2H_4$ has 4 hydrogen atoms. In the product $H_2O$, to balance the 4 hydrogen atoms from $N_2H_4$, the coefficient of $H_2O$ should be 2 as each $H_2O$ molecule has 2 hydrogen atoms.

Step3: Balance oxygen atoms

The product side has 2 oxygen atoms from $2H_2O$. So, the coefficient of $H_2O_2$ (which has 2 oxygen atoms) should be 2 to balance the oxygen atoms.
The balanced chemical equation is $N_2H_4(g)+2H_2O_2(g)
ightarrow N_2(g) + 4H_2O(g)$

Answer:

C. 1, 2, 1, 4