Calculate the mole fraction of MgCl2 in a solution created by dissolving 132.1g of MgCl2 in 175mL of water.

Mol fraction MgCl2 = 0.125

Explanation:

Step 1: Data given

Molar mass MgCl2 = 95.21 g/mol

Mass of MgCl2 = 132.1 grams

Volume of water = 175 mL

Density of water = 1g/mL

Molar mass H2O = 18.02 g/mol

Step 2: Calculate mass of water

Mass water = 1g/mL *175 mL

Mass of water = 175 grams

Step 3: Calculate moles H2O

Moles H2O = mass H2O / molar mass H2O

Moles H2O = 175.0 grams / 18.02 g/mol

Moles H2O = 9.711 moles

Step 4: Calculate moles MgCl2

Moles MgCl2 = 132.1 grams / 95.21 g/mol

Moles MgCl2 = 1.387 moles

Step 5: Calculate total moles

Total moles = 9.711 moles + 1.387 moles

Total moles = 11.098 moles

Step 5: calculate mol fraction

Mol fraction water = 9.711 moles / 11.098 moles = 0.875

Mol fraction MgCl2 = 1.387 moles / 11.098 moles = 0.125

0.875 + 0.125 = 1

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