Zadania z chemii IB HL

Determine, using a suitable construction drawn on the graph, the initial rate at which $\ce{CO2(g)}$ is released, in $\mathrm{g\,s^{-1}}$, in the reaction with 1.20 $\mathrm{mol\,dm^{-3}}$ $\ce{HNO3(aq)}$.

For the runs with 0.40 and 0.80 $\mathrm{mol\,dm^{-3}}$ $\ce{HNO3(aq)}$, suggest which reactant, $\ce{CaCO3(s)}$ or $\ce{HNO3(aq)}$, was the limiting reagent. Give a reason for your answer.

If the reaction with 0.80 $\mathrm{mol\,dm^{-3}}$ $\ce{HNO3(aq)}$ went to completion, the theoretical mass of $\ce{CO2(g)}$ released would be 1.76 g. (i) Use the graph to determine the mass, in g, of $\ce{CO2(g)}$ actually released in this reaction. (ii)…

Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, $\ce{CO}$, with bromine vapour, $\ce{Br2}$, started by ultraviolet light. The questions below treat this hypothetical route with the bond-enthalpy model and the entropy…

In moist air carbonyl dibromide is slowly hydrolyzed: $\ce{Br2CO(g) + H2O(g) -> CO2(g) + 2HBr(g)}$ (i) Suggest a method of monitoring the progress of this reaction at constant temperature so that its rate can be determined. (ii) Outline two reasons why a…

The mass spectrum of carbonyl dibromide is shown below. Bromine has two isotopes, $\ce{^{79}Br}$ and $\ce{^{81}Br}$, of almost equal abundance. (i) Explain the origin of the peaks that appear at m/z values smaller than those of the molecular ion. (ii) Deduce…

What volume of propane gas, in $\mathrm{cm^3}$, must be burned completely in oxygen to give 90 $\mathrm{cm^3}$ of carbon dioxide, all volumes being measured at the same temperature and pressure? $\ce{C3H8(g) + 5O2(g) -> 3CO2(g) + 4H2O(g)}$ A. 18 B. 30 C. 90 D.…

(i) Suggest a reason for the slight change in colour observed after the night in the oven. (ii) Suggest how the students could make sure that dehydration in the crucible was complete. (iii) Suggest one way in which the students could reduce the effect of…