BThe marble chips have all reacted.[1]
The acid is in excess, so the marble chips are the limiting reactant. When they are used up, no more gas forms.
Cusing a larger volume of the same acid[1]
More acid of the same concentration has the same number of particles per unit volume, so the frequency of effective collisions is unchanged.
The volume of gas given off and the mass of the reaction mixture. [1]
A collision with energy greater than or equal to the activation energy, which leads to a reaction. [1]
A substance that increases the rate of a reaction without being chemically changed at the end of the reaction. [1]
Particles have more kinetic energy and collide more often, and more of them have energy greater than or equal to the activation energy. [1]
So the frequency of effective collisions increases. [1]
C2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)[1]
Pressure affects the rate only when a reactant is a gas. In C, the reactants are a solid and a liquid.
Cslower, and a larger volume[1]
Lumps of catalyst have a smaller surface area, so the rate is slower. Twice the mass of potassium chlorate gives twice the volume of oxygen.
When warmed, the particles gain energy and move faster, and more particles have energy greater than or equal to the activation energy. [1]
This leads to a higher frequency of effective collisions between the reacting molecules. [1]
A catalyst provides an alternative pathway with a lower activation energy for the reaction. [1]
This leads to a higher frequency of effective collisions between the particles, so the rate of reaction is higher. [1]