A big, irregular-shaped contained water , the sp. Conductance of which was 2.56 xx 10^(-5) "mho cm"^(-1). 500g of NaCl was then added to the water and the sp. cond. after the addition of NaCl, was found to be 3.10 xx 10^(-5) "mho cm"^(-1). Find the capacity of the vessel if it is fully filled with water. (Lambda_(NaCl)^(@) = 149.9)

A big, irregular-shaped contained water , the sp. Conductance of which

1.	A big, irregular-shaped contained water , the sp. Conductance of which was 2.56 xx 10^(-5) "mho cm"^(-1). 500g of NaCl was then added to the water and the sp. cond. after the addition of NaCl, was found to be 3.10 xx 10^(-5) "mho cm"^(-1). Find the capacity of the vessel if it is fully filled with water. (Lambda_(NaCl)^(@) = 149.9)
Answer» SOLUTION :Let the volume of the vessel be V CC. Number of equivalent of NaCl `= ("wt. in grams")/("eq. weight")` `= (500)/(58.5) = 8.547` `therefore` volume of water (cc) containing 1 eq. of NaCl `= (V)/(8.547)` The sp. cond. of the NaCl solution (only due to presence of `NA^(+)` and `Cl^(-)` ions) `= 3.10 xx 10^(-5) - 2.56 xx 10^(-5)` `= 0.54 xx 10^(-5)` `therefore Lambda_(NaCl) = 0.54 xx 10^(-5) xx (V)/(8.547)` Sicne the vessel is big, the resulting solution MAY be supposed to be dilute. `therefore Lambda_(NaCl) = Lambda_(NaCl)^(@)` `0.54 xx 10^(-5) xx(V)/(8.547) = 149.9` `V = 2.37 xx 10^(8)` cc.