Question
What is represented by the dotted line on the enthalpy profile?
A. Reaction carried out at a lower temperature
B. Reaction is reversible
C. A catalyst is used
D. Collision frequency has increased
Answer/Explanation
Markscheme: C
Question
What happens to the average kinetic energy, KE, of the particles in a gas when the absolute temperature is doubled?
\(KE = \frac{1}{2} mv^2\)
A. increases by a factor of 2
B. Decreases by a factor of 2
C. Increases by a factor of 4
D. Decreases by a factor of 4
▶️Answer/Explanation
Markscheme: A
Question
Which is the species oxidized and the oxidizing agent in the reaction?
$$
\mathrm{MnO}_2(\mathrm{~s})+4 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{MnCl}_2(\mathrm{aq})+\mathrm{Cl}_2(\mathrm{~g})+2 \mathrm{H}_2 \mathrm{O}(\mathrm{l})
$$
▶️Answer/Explanation
Ans:D
Question
Which describes an exothermic reaction?
Answer/Explanation
Solution:D
Question
The graph shows the Maxwell-Boltzmann energy distribution curve for a given gas at a certain temperature.
How would the curve change if the temperature of the gas decreases while the other conditions remain constant?
A. The maximum would be lower and to the left of $\mathrm{M}$.
B. The maximum would be lower and to the right of $\mathrm{M}$.
C. The maximum would be higher and to the left of $\mathrm{M}$.
D. The maximum would be higher and to the right of $\mathrm{M}$.
Answer/Explanation
Solution:C