Zadanie 3
What is the maximum number of electrons that can occupy the n = 4 main energy level? A. 8 B. 16 C. 18 D. 32
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What is the maximum number of electrons that can occupy the n = 4 main energy level? A. 8 B. 16 C. 18 D. 32
Determine, using a suitable construction drawn on the graph, the initial rate at which CO2(g) is released, in g s−1, in the reaction with 1.20 mol dm−3 HNO3(aq).
For the runs with 0.40 and 0.80 mol dm−3 HNO3(aq), suggest which reactant, CaCO3(s) or HNO3(aq), was the limiting reagent. Give a reason for your answer.
If the reaction with 0.80 mol dm−3 HNO3(aq) went to completion, the theoretical mass of CO2(g) released would be 1.76 g. (i) Use the graph to determine the mass, in g, of CO2(g) actually released in this reaction. (ii)…
Suppose carbonyl dibromide were made by a free-radical chain reaction of carbon monoxide, CO, with bromine vapour, 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: Br2CO(g) + H2O(g) → CO2(g) + 2 HBr(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, and , 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 cm3, must be burned completely in oxygen to give 90 cm3 of carbon dioxide, all volumes being measured at the same temperature and pressure? C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(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…
Each student used a different mass of the hydrated salt. The results of the whole class are shown below (Mr of H2O = 18.02). (i) Determine the two missing values in the table. The class results were plotted on the graph below. (ii) Draw a line of…