Answer:
X- HCl
Y- NaOH
Z- NaCl
Explanation:
An acid turns blue litmus paper red, exhibits low pH(due to high concentration of hydrogen ions) and also react with magnesium as follows;
2HCl(aq) + Mg(s)-------> MgCl2(aq) + H2(g)
A base turns red litmus paper blue, exhibits a high pH (due to low concentration of hydrogen ions) and does not react with magnesium.
A salt does not react with litmus paper, exhibits a neutral pH of 7 and does not react with magnesium.
