There are several ways to calculate the enthalpy of a reaction, \( \Delta H_{r x n} \). Three methods were involved in the enthalpy lab. In the method of \( \Delta H_{r x n}=-q_{s o l n} \), the [Select] used. In the method of Hess's law, [Select] theoretical prediction as if under the standard conditions, [Select] is used.

During a reaction, the enthalpy of formation of an intermediate is -286 \( \mathrm{~kJ} / \mathrm{mol} \). During the reaction, 2 moles of the intermediate are produced. What is the enthalpy value for this step of the reaction? A. -572 kJ B. 572 kJ C. 286 kJ D. -286 kJ

5 What is meant by the term hygroscopic when referring to brake fluid?

The electronic configuration of one element is \(1s^ 2 2s^ 2 2p^ 6 3s^ 2 3p^ 6 3d^ { 10} 4s^ 1\). What is same group which is recently discovered?

\( \begin{array}{ll}\text { a) } \mathrm{Ca}(\mathrm{OH})_{2}+? \rightarrow \mathrm{CaCl}_{2}+\mathrm{H}_{2} \mathrm{O} & \text { b) } \mathrm{Ca}(\mathrm{OH})_{2}+? \rightarrow ?+\mathrm{NaOH} \\ \text { c) } \mathrm{Ca}(\mathrm{OH})_{2}+\mathrm{CO}_{2} \rightarrow ?+? & \text { d) } \mathrm{Ca}(\mathrm{OH})_{2}+? \rightarrow \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}+\end{array} \)

What does word root indicate in IUPAC name? b. Write the suffix for doubly bonded \( (\mathrm{C}=\mathrm{C}) \) alcohol. c. Ifsame substituent is repeated thrice, which prefix is added to word root? \& Write IUPAC name of \( \mathrm{CH}_{3}-\mathrm{CH}(\mathrm{CI})-\mathrm{CH}_{2}-\mathrm{COOH} \). e. Which group is selected as suffix if -OH and -CHO both are present in the compound?