\(NH_{3(g)} + HCl_{(g)} → NH_4Cl_{(s)}\)
The entropy change in the system above is

Which of the following reaction is endothermic?

A catalyst speeds up the rate of chemical reaction by

The rate of a reaction usually decreases with a decrease in the concentration of reactants because

The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is