Determine the number of moles of calcium carbonate with 10% impurities, which reacts with 21.9 g of hydrochloric acid.

0.297 moles of calcium carbonate.

Solution:

Number of moles of HCl = moles

According to reaction

Two moles of HCl are reacting with one mole of , then 0.6 moles of HCl will react with:

=

Moles of calcium carbonate reacted = 0.3 moles

In 0.3 moles of calcium carbonate 10% impurities is present i.e.

of impurity.

Actual number of moles of calcium carbonate reacted = 0.3 - 0.003 = 0.297 moles.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml