Question

If ${N_2}{H_4}$ is oxidised to${N_2}$, what would be the equivalent weight of ${N_2}{H_4}$?

Answer 1

Equivalent weight of the substance is the mass of that particular substance which will replace $1g$ of hydrogen, $8g$of oxygen or $35.5g$of chlorine. Equivalent weight can be determined by knowing the oxidation states of a particular atom or an element in a compound.

Complete answer:
To solve this question first we need to know about the ${N_2}{H_4}$and oxidation states of nitrogen in hydrazine and in nitrogen gas.
So, ${N_2}{H_4}$ is commonly known as hydrazine, and is a colourless dense liquid with a strong smell. Hydrazine is a strong reducing agent so let’s see its oxidation state.
For ${N_2}{H_4}$
$2x + (1 \times 4) = 0$
$x = - 2$
So, the oxidation state of N in ${N_2}{H_4}$ is $- 2$ .
And we already know, by convention, the oxidation state of nitrogen gas ${N_2}$ is$0$. Thus, we can see the change in the oxidation state from $- 2$ to $0$ be$2$.
Since, in hydrazine, ${N_2}{H_4}$ we are having two nitrogen atoms ${N_2}$ , so we will multiply it by 2
So our n = $4$
Now let’s recall the formula of equivalent weight,
$Equivalent{\text{ }}weight = \dfrac{{gram{\text{ atomic weight }}}}{{valence}}$
Since, the atomic weight of hydrazine ${N_2}{H_4}$is $32$
So, putting the value of atomic weight and n in formula, we get,
$Equivalent{\text{ }}weight = \dfrac{{32{\text{ }}}}{4} = 8$
Therefore, the answer to our question is 8 i.e. the equivalent weight of ${N_2}{H_4}$ , if it gets oxidized to ${N_2}$ , will be $8$ .

Note:
Hydrazine has many applications like it is used as a rocket fuel propellant in combination with dinitrogen tetroxide . Hydrazine is really toxic as it gets absorbed on skin .hydrazine is best known for spreading invisible fire as it has no flames .