The heat of combustion of carbon to $\text{CO}_2$ is $-393.5\ \text{kJ/mol}$. The heat released upon formation of 35.2 g of $\text{CO}_2$ from carbon and oxygen gas is

Calculate the enthalpy change when 6 g. $\text{CO(g)}$ reacts with sufficient $\text{NO}_2\text{(g)}$ according to the following reaction
$4\,\text{CO(g)} + 2\,\text{NO}_2\text{(g)} \rightarrow 4\,\text{CO}_2\text{(g)} + 2\text{N}_2\text{(g)}\,;\ \Delta_r H^0 = -1200\ \text{kJ}$

Identify the process that proceeds with no heat exchange between system and surrounding.

What is the change in entropy of surrounding for the reaction,
$\text{H}_{2(g)} + 1/2\ \text{O}_{2(g)} \rightarrow \text{H}_2\text{O}_{(l)}$
at 298 K if standard enthalpy of formation of water is $-286$ kJ ?