In an experiment, 3.264 g of zinc chloride, zncl2, yielded 1.468 g of zinc metal. assuming that the original sample was pure, how much zinc should be obtained? was all zinc possible from the sample recovered? what is the calculated percentage recovery? (answer much contain proper number of significant figures).

The percentage recovery is 93.95%

Zinc Chloride (ZnCl₂) decomposes to yield Zinc metal and chlorine gas.

The equation for the reaction is:

ZnCl₂ → Zn(s) + Cl₂(g)

From the reaction:

1 mole of ZnCl₂ decomposes to yield 1 mole of Zn

We are required to calculate the percentage recovery  of Zn:

First we calculate the Number of moles of ZnCl₂

Number of moles = Mass ÷ Molar mass

                             = 3.264 g ÷ 136.286 g/mol

                             = 0.0239 Moles

Second, we calculate the mole of Zn that would have been obtained if the sample was pure..

From the equation:

But, from the equation 1 mole of ZnCl₂ decomposes to yield 1 mole of Zn

Therefore, the mole ratio is 1 : 1

Hence, moles of Zn = 0.0239 moles

Thirdly, the mass of Zinc that would have been obtained if the sample was pure

Moles of Zn = 0.0239 moles

But; Mass = Moles × Molar mass

Molar mass of Zn = 65.38 g/mol

Therefore;

Mass of Zn = 0.0239 moles × 65.38 g/mol

                  = 1.5626 g

Fourth, we calculate the percentage recovery

Percentage recovery is given by dividing the amount of sample collected by the amount of sample that was supposed to be collected and expressing it as a percentage.

Therefore;

Amount of Zn obtained = 1.468 g

Amount of Zn that was supposed to be obtained = 1.5626 g

% recovery = (1.468 g÷ 1.5626 g)100%

                  =93.95%

Therefore, the percentage recovery is 93.95%

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