A2.00−l sample of water contains 150.0 μg of lead. calculate the concentration of lead in ppm.

Given the volume of water sample = 2.00 L

Mass of lead = 150.0 μg

When we say that a solution is 1 ppm in concentration, it means that there is one part of solute per million parts of the solution.

One ppm = 1 mg solute/L solution

The concentration of lead in ppm:

150.0 μg × ×

= 0.075 ppm

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