Step-by-step explanation:
MgCl2(aq) + NaOH(aq) = Mg(OH)2(s) + NaCl. Both magnesium nitrate and sodium hydroxide solutions are colourless solutions. When they react with each other, a white precipitate (Mg(OH)2) and a colourless solution is given. Sodium chloride exists in the colourless aqueous solution.