Chemistry Past Questions and Answers

What does ∆H represent in the following equation ? Cl<sub style='font-size: smaller;'>(g)</sub> + e- → CI- <sub style='font-size: smaller;'>(g)</sub>; ∆H = - 363 kJ mol-<sup style='font-size: smaller;'>1</sup>

Consider the following equation: Ag<sup style='font-size: smaller;'>+</sup><sub style='font-size: smaller;'>(aq)</sub> + CI-<sub style='font-size: smaller;'>(aq)</sub> → Ag<sup style='font-size: smaller;'>+</sup>CI- <sub style='font-size: smaller;'>(s)</sub> ; ∆H = _65.7 kJmol<sup style='font-size: smaller;'>-1</sup>. From the equation, it can be deduced that

A reaction is represented by the equation below. A<sub style='font-size: smaller;'>2(g)</sub> + B<sub style='font-size: smaller;'>2(g)</sub> 2AB<sub style='font-size: smaller;'>(g)</sub>; ∆H = +X kJmol<sup style='font-size: smaller;'>-1</sup> Which of the following statements about the system is correct?

What is the oxidation number of nitrogen in AI(NO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>3</sub>?

What is oxidized in the reaction represented by the following equation? 3CU + 8HNO<sub style='font-size: smaller;'>3</sub> → 3Cu(NO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2</sub> + 2NO + 4H<sub style='font-size: smaller;'>2</sub>O