Question

2s = o 1044
2co + o₂ → 2co₂ 2c≡o 2148
o = o 499
4c = o 2956
which reaction is endothermic?
(1 point)
o s + o₂ → so₂
o 2co + o₂ → 2co₂
o n₂ + o₂ → 2no
o c + o₂ → co₂

Explanation:

Step1: Recall endothermic reaction concept

An endothermic reaction absorbs heat from the surroundings. Combustion reactions (reactions of elements with oxygen to form oxides like $S + O_2
ightarrow SO_2$, $2CO + O_2
ightarrow 2CO_2$, $C + O_2
ightarrow CO_2$) are exothermic as they release heat.

Step2: Analyze nitrogen - oxygen reaction

The reaction $N_2+O_2
ightarrow 2NO$ requires a significant amount of energy input (usually from high - temperature sources like lightning) to break the strong triple bond in $N_2$ and the double bond in $O_2$. It is endothermic.

Answer:

$N_2 + O_2
ightarrow 2NO$