Answer: Yes, the student is right, one should use pellets of the reactant should be heated and stirred for mixing properly.
Explanation:
In case of smaller particles the surface area that is being exposed increases and the due to this the reaction occurs faster.
Increasing the temperature of the temperature, increases the kinetic energy of the particles which helps in easy mixing of the particles.
The collision in between the particles also increase while stirring and thus the rate of reaction increases.
So, the heating and stirring is more preferred over powered reactant for making a solution quickly.