Question 1
One factor affecting the rate of reaction is the presence of a catalyst. Name three other factors that affect it.
The right answer is the one marked above.
The surface area of the reactants, the temperature the reaction runs at, and the concentration of the reactants. For gaseous reactants the last of these shows up as pressure.
Colour, smell, price and the shape of the vessel do nothing to the number of collisions between reactant particles, so they do nothing to the rate either.