Step-by-step explanation:
The two figures are missing so I can't tell which reactions will proceed faster, but the answer will follow this logic:
If the two samples of Mg(s) are equal, the two amounts of HCl(aq) are equal, the operation conditions are the same (Temperature, pressure,etc.), the difference in the speed of reaction will only depend difference in the quality of mixing of the Mg(s).
Being that said:
- If the particles of Mg are poorly distributed in the solution and very close to each other, the surface that interacts with HCl is small and in result the speed of reaction is lower.
- On the other hand, if the Mg is well mixed and its concentration is almost homogeneous in all the solution, the surface of reaction will be bigger and the speed of reaction higher than the other case.