What is the purpose of adding sulfuric acid in the preparation of potash alum?

Which chemical is added to the solution to promote crystallization during the preparation of potash alum?

After the aluminum sulfate is formed in the experiment, what is the next step to obtain Potash Alum crystals?

In the final step of the experiment, how are Potash Alum crystals separated from the solution?

Which of the following precautions is essential when mixing potassium hydroxide $\left(\mathrm{KOH}\right)$ with sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ in the preparation of potash alum?

What is the purpose of washing the alum crystals with cold water during the final steps of the experiment?