Calculate the quantities fo reagents required to soften 100 L of water containing the following impurities per litre in it. (a). CaCO_3=20, (b). MgCl_2=8.0g, (c). MgSO_4=7g, (d). MgCO_3=4.5g (e). CaSO_4=2.5g (f). NaCl=6.0g Purity of lime =90% purity of soda=99.5%

Calculate the quantities fo reagents required to soften 100 L of water

1.	Calculate the quantities fo reagents required to soften 100 L of water containing the following impurities per litre in it. (a). CaCO_3=20, (b). MgCl_2=8.0g, (c). MgSO_4=7g, (d). MgCO_3=4.5g (e). CaSO_4=2.5g (f). NaCl=6.0g Purity of lime =90% purity of soda=99.5%
Answer» Solution :(a). `20 g CaCO_(3)=20g CaCO_(3)` (b). `8 g MgCl_(2)=(8xx100)/(95)=8.42 g of CaCO_(3)` (c). `7g MgSO_(4)=(7xx100)/(120)=5.83 g of CaCO_(3)` (d). `4.5 of MgCO_(3)` (Present as bicarbonate)`-=(4.5xx100)/(84)` `-=5.35g of CaCO_(3)` (e). `2.5g CaSO_(4)=(2.5xx100)/(136)=1.83g of CaCO_(3)` (f). NaCl does not contribute to hardness. Lime requirement: `=(74)/(100)[20+2xx5.35+8.42+5.83]` `=33.26 g of CaCO_(3)(eq)/(L) of H_(2)O` `=33.26xx100g of CaCO_(3)(eq)/(100L) of H_(2)O` `=3.326 kg` Weight of lime of `90%` PURITY`=(3.326xx100)/(90)=3.69kg` Soda requirement: `=(106)/(100)[8.42+5.83+1.83]` `=17.04g of CaCO_(3)(eq)/(L) of H_(2)O` `=17.04xx100g of CaCO_(3)(eq)/(100L) of H_(2)O` `=1.704 kg` Weight of soda of `95.5%` purity`=(1.704xx100)/(95.5)=1784kg`