Which one of the following is always not negative?

$1 \, \text{mole}$ of $H_2SO_4$ is mixed with $2 \, \text{moles}$ of $NaOH$. The heat evolved will be

For the complete combustion of ethanol,$C_2H_5OH_{(l)} + 3O_{2(g)} \rightarrow 2CO_{2(g)} + 3H_2O_{(l)}$,the amount of heat produced as measured in a bomb calorimeter is $1364.47 \ kJ \ mol^{-1}$ at $25 \ ^oC$. Assuming ideality,the enthalpy of combustion,$\Delta_cH$,for the reaction will be: $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$ .....$kJ \ mol^{-1}$

$A$ swimmer coming out from a pool is covered with a film of water weighing about $18 \ g$. How much heat must be supplied to evaporate this water at $298 \ K$? Calculate the internal energy of vaporisation at $298 \ K$. Given: $\Delta_{vap} H^{\ominus}$ for water at $298 \ K = 44.01 \ kJ \ mol^{-1}$.

Which of the following statements is incorrect?

Consider the reversible processes for $1.0 \ mol$ of an ideal gas. $w_1, w_2, w_3$ and $w_4$ represent work done (in calories) in the processes $1, 2, 3$ and $4$, respectively; $\Delta U_2$ and $\Delta U_4$ are changes in the internal energy for the processes $2$ and $4$, respectively. (use $R = 2 \ cal \ K^{-1} \ mol^{-1}$). The correct option is: