Question

Magnesium can interfere with the measurement of the calcium concentration in water samples using colorimetric tests. Write a balanced chemical equation for the reaction of dissolved magnesium chloride with sodium hydroxide to form magnesium hydroxide as a precipitate and sodium chloride.

(Reactants -> Products)

Answer 1

`MgCl_2+2NaOH\rightarrow 2NaCl+Mg(OH)_2`

Step-by-step explanation:

Hello.

In this case, since aqueous magnesium chloride reacts with aqueous sodium hydroxide, a precipitate product, magnesium hydroxide is formed as well as aqueous sodium chloride as shown below:

`MgCl_2+NaOH\rightarrow NaCl+Mg(OH)_2`

However, since there are two chlorine atoms at the reactants we need a 2 before NaCl on the products in order to balance it. Moreover, there one OH at the reactants and two OH at the products, that is why we also add a 2 before NaCl as shown below:

`MgCl_2+2NaOH\rightarrow 2NaCl+Mg(OH)_2`

Best regards!