Question

1. In

is added.

20 ml of a 0.1 mole.L-1 of copper II sulfate solution, some granulated Zinc

a. What is the minimum amount of Zinc that should be used to decolorize the solution?

b. Calculate the concentration of the chemical species that are present in the resulting colorless solution.

Answer 1

The equation for the reaction is;

$Zn+CuSO4\to Cu+ZnSO_4$

a) Moles of $Zn$ required to decolorize $CuSO_4$ $=$ Moles of $CuSO_4$

$=0.02L\times 0.10 mol/L$

$=0.002mole Zn$ $\times 0.002M\times 65.38g/molZn$

$=0.1308gZn$

b) In finding the concentration, we use;

$M_1V_1=M_2V_2$

$=(20mL)(0.1M)=M_2(1000mL)$

$=$ $2mL\over 1000M/mL$ $=0.002M$

Concentration of the end reactants $= 0.002M$

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