Hydrazine, $\text{N}_2\text{H}_4$, is commonly used as a rocket fuel because it reacts with oxygen in the way shown, giving ‘environmentally friendly’ gases. $\text{N}_2\text{H}_4\text{(l)} + \text{O}_2\text{(g)} \rightarrow \text{N}_2\text{(g)} + 2\text{H}_2\text{O(g)} \quad \Delta H = -534 \text{ kJ mol}^{-1}$. Even though hydrazine is used as a rocket fuel, it does not burn spontaneously in oxygen. Which statement gives the reason hydrazine does not burn spontaneously?
- AHydrazine is a liquid.
- BThe activation energy is too high.
- CThe N≡N bond is very strong.
- DThe reaction is exothermic.