When 5.00 g of fecl3 . xh2o are heated, 2.00 g of h20 are driven off. find the chemical formula and the name of the hydrate

The chemical formula is FeCL3* 6H2O

The  name of this hydrate is Iron(III) Chloride Hexahydrate  or Ferric Chloride Hexahydrate

Explanation:

Step 1: Data given

Mass of FeCl3 * xH2O = 5 grams

mass of H2O = 2 grams

Molar mass of FeCl3 = 162.2 g/mol

Molar mass of H2O = 18.02 g/mol

Step 2: Calculate mass of FeCl3

After heating, the remaining mass, is the mass of FeCl3, because H2O (2 grams) is driven off.

Mass FeCl3 = 5-2 = 3grams

Step 3: Calculate number of moles

Number of moles = mass / molar mass

Moles of FeCl3 = 3.00 grams / 162.2 g/mol = 0.0185 moles

Moles of H2O = 2.00 grams / 18.02 g/mol = 0.111 moles

Step 4: Divide the number of moles by the smallest number of moles

The smallest number is 0.0185; so we will divide both by 0.0185

FeCl3 = 0.0185 /0.0185 = 1

H2O = 0.111 / 0.0185 ≈ 6

This means for 1 mole of FeCl3 we have 6 moles of H2O

The chemical formula is FeCL3* 6H2O

The  name of this hydrate is Iron(III) Chloride Hexahydrate  or Ferric Chloride Hexahydrate

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.