Epsom salt is mgso4·7 h2o. what does the chemical formula become when this hydrate is gently heated?

Epsom salt, magnesium sulphate, or MgSO4.7H2O comes in different hydrates.

The heptahydrate (.7H2O) comes in as Epsom salt.

It readily loses one water of crystallization, or by gentle heating, to become the hexahydrate, (.6H2O).

When heated to 150 ° C, it further lose water of crystallization to the monohydrate (.H2O)

Finally, when heated to 200 ° C, it becomes anhydrous, i.e. a powder that has no more water of crystallization.

(ref. Wiki)

Answer;

= 226 Liters of oxygen

Explanation;

We use the equation;

LiClO4 (s) → 2O2 (g) + LiCl, to get the moles of oxygen;

Moles of  LiClO4;

(500 g LiClO4) / (106.3916 g LiClO4/mol)

= 4.6996 moles

Moles of oxygen;

But, for every 1 mol LiClO4, two moles of O2 are produced;

= 9.3992 moles of Oxygen

V = nRT / P

= (9.3992 mol) x (8.3144621 L kPa/K mol) x (21 + 273) K / (101.5 kPa)

= 226 L of oxygen