Question

q# 34. _nh₃ + o₂ → _n₂ + _h₂o
after correctly balancing this chemical equation, what coefficient will go before nh₃?
enter the correct answer in the box.

Explanation:

Step1: Balance N atoms

Let the coefficient of \(NH_3\) be \(x\) and \(N_2\) be \(y\). From N atoms: \(x = 2y\). Let's start with \(x = 2\), then \(y = 1\) (but check H and O).

Step2: Balance H atoms

From \(NH_3\) and \(H_2O\): \(3x = 2z\) (let \(z\) be coefficient of \(H_2O\)). If \(x = 2\), \(3\times2 = 2z\Rightarrow z = 3\).

Step3: Balance O atoms

From \(O_2\) and \(H_2O\): \(2w = z\) (let \(w\) be coefficient of \(O_2\)). \(z = 3\), so \(2w = 3\) (not integer). Adjust \(x\) to 4 (so \(y = 2\) for N). Then \(3\times4 = 2z\Rightarrow z = 6\). Now \(2w = 6\Rightarrow w = 3\). Check: \(4NH_3 + 3O_2
ightarrow 2N_2 + 6H_2O\). N: 4=4, H:12=12, O:6=6. Balanced.

Answer:

4