Question

Which answer does not describe the following reaction?

NO (g) + O2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. 2 NO2 (g)

The reaction is in dynamic equilibrium.

The reaction does not go to completion.

The reaction is reversible.

The concentration of reactants and products will be equal.

Answer 1

Which of the following chemical reactions is an oxidation-reduction reaction?

Fe2O3 + 3CO yields 2Fe + 3CO2

MgSO4 + 2KIyields K2SO4 + MgI2

NaNO3 + KCl yields KNO3 + NaCl

Cu(NO3)2 + 2HBryields CuBr2 + 2HNO3

Answer 2

Which of the following reactions results in a decrease in entropy?

CaCO3 (s) yields CaO (s) + CO2 (g)

N2O4 (g) yields 2NO2 (g)

CaO (s) + SO3 (g) yields CaSO4 (s)

2NH3 (g) yields N2 (g) + 3H2 (g)

Answer 3

CaO + SO3 yields CaSO4. This reaction results in a decrease in entropy because you get solid calcium sulphate, which is more ordered as compared to other gaseous products.


Reaction 1 of Fe2O3 with CO is an oxidation-reduction reaction, since Fe is reduced while C is oxidised.

Answer 4

For the first question, the last option does not describe the reaction given,. The system is in dynamic equilibrium, which means rates of forward and backward reactions are equal. However, the concentrations of products and reactants may not necessarily be equal.