………wastes soap and affect the cleaning action of soap.
a) hard water
b) soft water
c) both a & b
d) all of these
Water becomes hard when it dissolves …… from the water.
a) gypsum
b) lime stone
c) both a & b
d) none of these
The chemical formula of gypsum is …………
a) CaSO4.2H2O
b) CaCO3
c) MgCO3
d) Mg(HCO3)
The rain water on its way to ground, dissolve ……….from the atmosphere.
a) CO2
b) C
c) O
d) H
Water which contain CO2 has the ability to dissolve the small amount of ……….to form different bicarbonates.
a) CO2
b) CaO
c) CaCO3
d) MgCO3
MgCO3 reacts with H2O and CO2 to form…..
a) Mg(HCO3)
b) Ca(HCO3)
c) CaCO3
d) MgCO3
