$A$ solution of $500 \ mL$ of $0.2 \ M \ KOH$ and $500 \ mL$ of $0.2 \ M \ HCl$ is mixed and stirred; the rise in temperature is $T_1$. The experiment is repeated using $250 \ mL$ each of solution,the temperature raised is $T_2$. Which of the following is true?

In a constant volume calorimeter,$3.5 \ g$ of a gas with molecular weight $28$ was burnt in excess oxygen at $298.0 \ K$. The temperature of the calorimeter was found to increase from $298.0 \ K$ to $298.45 \ K$ due to the combustion process. Given that the heat capacity of the calorimeter is $2.5 \ kJ \ K^{-1}$,the numerical value for the enthalpy of combustion of the gas in $kJ \ mol^{-1}$ is

The process of evaporation of a liquid is completed by .......

For the reaction $2Cl_{(s)} \to Cl_{2(s)}$,the signs of $\Delta H$ and $\Delta S$ respectively are

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If $T_i$ is the initial temperature and $T_f$ is the final temperature,which of the following statements is correct?

$A$ cylinder of gas supplied by Bharat Petroleum is assumed to contain $14 \ kg$ of butane. If a normal family requires $20,000 \ kJ$ of energy per day for cooking,how many days will the butane gas in the cylinder last? ($\Delta H_c$ of $C_4H_{10} = -2658 \ kJ/mole$)