The formula of gypsum and that of plaster of parls are CaSO4.xH2O and CaSO4.yH2O respectively. The difference x-y equals to;

1) 1
2) 3/2
3) 5/2
4) 1/2

Help me

Explanation:

Given formula of Gypsum:

               CaSO₄. xH₂O,

       True formula:

              CaSO₄. 2H₂O,  x  = 2

Formula of plaster of paris  = CaSO₄. H₂O,

               y  =  

The difference between x and y; x - y:

               x  - y = 2 -    =  

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