To dissolve 4 g of bivalent metal oxide, 25 g of chloride acid with a mass fraction of HCL

To dissolve 4 g of bivalent metal oxide, 25 g of chloride acid with a mass fraction of HCL of 29.2% were needed. Identify the metal

Let M be an unknown divalent metal and MO its oxide.

Let’s write the reaction equation:

MO + 2HCl = MCl2 + H2O

Let’s find the amount of substance MO:

v (MO) = m (MO) / M (MO) = 4 / (M (M) + 16) (mol).

Let’s find the mass of HCl:

m (HCl) = mr.-pa (HCl) * w (HCl) / 100 = 25 * 29.2 / 100 = 7.3 (g).

Let’s find the amount of HCl substance:

v (HCl) = m (HCl) / M (HCl) = 7.3 / 36.5 = 0.2 (mol).

According to the reaction equation, 1 mol of MO reacts with 2 mol of HCl, therefore:

v (MO) = v (HCl) / 2,

4 / (M (M) + 16) = 0.2 / 2,

M (M) = 24 (g / mol), which corresponds to magnesium (Mg).

Answer: magnesium (Mg).