Question

How many tons of zinc can be obtained from 976 tons of zinc ore that is 78.0% zinc carbonate?

Answer 1

First, calculating the amount of zinc carbonate by multiplying the given mass of the ore by the percent zinc carbonate. 
                          mass of zinc carbonate = (976 tons)(0.78) 
                                                       = 761.28 tons
Then, calculate for %Zn in zinc carbonate
                           %Zn = ((65.38) / (125.39)) x 100%
                                          % Zn = 52.141%
tons of Zn from the sample,
                           mass of Zn = (761.28 tons)(0.52141)
                                              = 396.94 tons Zn

Answer 2

Answer : The amount of zinc obtained can be 396.9 tons.

Explanation :

First we have to calculate the amount zinc carbonate in 976 tons.

Amount of zinc carbonate = $\frac{78.0}{100}\times 976\text{ tons}=761.28\text{ tons}$

Now we have to calculate the percentage of zinc in zinc carbonate.

As we know that,

Atomic mass of zinc = 65.38 g

Atomic mass of zinc carbonate = 125.38 g

$\% \text{ of zinc}=\frac{\text{Atomic mass of zinc}}{\text{Atomic mass of zinc carbonate}}\times 100$

$\% \text{ of zinc}=\frac{65.38}{125.38}\times 100=52.14\%$

Now we have to calculate the amount of zinc in 761.28 tons.

Amount of zinc = $\frac{52.14}{100}\times 761.28\text{ tons}=396.9\text{ tons}$

Therefore, the amount of zinc obtained can be 396.9 tons.