Question

The formation of carbon dioxide by reacting Carbon with excess Oxygen, is exothermic. What will be the sign of $\Delta H$?

• A. $\Delta H$ is positive
• B. $\Delta H$ is negative
• C. $\Delta H$ is zero
• D. None of these

Answer 1

The correct option is B $\Delta H$ is negative

$C$ $+$ $O_2$ $=$ $C{O}_2$ $+$ $Heat$
When carbon dioxide is produced by reacting Carbon and Oxygen, $-393kJ$ of heat is produced or evolved. Thus, the reaction is exothermic in nature as heat is released. Hence, $\Delta H$ will be negative.