What is the enthalpy change (in $J$) for converting $9 \ g$ of $H_2O(l)$ at $+10^{\circ}C$ to $H_2O(l)$ at $+20^{\circ}C$? $(C_p(H_2O(l)) = 75 \ J \ mol^{-1} \ K^{-1})$

For which of the following reactions is $\Delta H$ approximately equal to $\Delta E$?

For the reaction,$2Cl_{(g)} \to Cl_{2_{(g)}}$,what are the signs of $\Delta H$ and $\Delta S$?

At $27\,^{\circ}C$,$1\, mole$ of an ideal gas expands reversibly and isothermally from $2\, atm$ to $1\, atm$. Then $\Delta H$ will be......$kJ$.

Fill in the blanks:
$(i)$ $A$ system that allows the exchange of energy but not matter with the surroundings is called a ........ .
$(ii)$ The total amount of energy consisting of the internal energy of a substance plus the product of its pressure and volume is called ........ .
$(iii)$ The change in energy that occurs when a chemical reaction is carried out at constant pressure is called ........ .

The internal energy of a substance $U$ is related to temperature $T$ in which of the following ways?