16. why can grinding a solid into a fine powder increase the rate of reaction?

The process of grinding or breaking a substance tends to increase the surface area of the substance. When the surface area increases, there is a better chance for reactants to react and form product. Hence, the more the surface area, the more will be the reaction rate.

The increase in surface area causes the substance to collide with more force with the other reactant and as a result, the reaction rate increases.

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