<p>10 litre of hard water required 5.6g of lime to remove hardness of water. Thus temporary hardness of water in terms of ppm of&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><mi>a</mi><mi>C</mi><msub><mi>O</mi><mn>3</mn></msub></math>&nbsp;is:</p>