Answer:
D.
Explanation:
The reaction is losing potential energy, which means that the reaction is losing that energy as heat. Exothermic is the loss of energy. Therefore it will be D.
Answer:
Reverse the
reaction
Explanation:
Reactions:

Overall:

As can be seen, in the overall reaction we have
in the reactants like in the second reaction and
in the products. The
is in the first reaction but as a reactant so we need to reverse that reaction:

Combining:


Answer:
The square root of the molar mass of B ÷ the square root of the molar mass of A
Explanation:
Graham’s Law applies to the effusion of gases:
The rate of effusion (r) of a gas is inversely proportional to the square root of its molar mass (M).
If you have two gases A and B, the ratio of their rates of effusion is
