Chemistry Past Questions and Answers

Elements P, Q, R, S have 6, 11, 15, & 17 electrons respectively.<br/><br/>Therefore, ____________

An element X forms the following compounds with chlorine \(NCl_4\), \(XC_3\). \(XC_2\) this illustrates the ____________

The oxidation state of chlorine in potassium chlorate is ____________

When carbon dioxide is bubbled into limewater, a white precipitate is formed. If the passage of the gas is continued,the precipitate disappears. <br/>The reasons for this is ____________

The following reactions are stages in important industrial processes <br/>(i) \(\mathrm{N}_{2(9)}+\mathrm{O}_{2}-2 \mathrm{NH}_{3(9)} \Delta \mathrm{H}\) is negative<br/>(ii) \(2 \mathrm{SO}_{2(g)}+\mathrm{O}_{2(g)}-2 \mathrm{SO}_{3(g)} \Delta \mathrm{H}\) is negative<br/>(iii) \(\mathrm{N}_{2(g)}+\mathrm{O}_{3(9)}-2 \mathrm{NO}_{(9)} \Delta \mathrm{H}\) is positive.<br/>Which of the above forward reactions is favoured by a decrease in the concentration of the pressure and an increase in temperature?