CHXII02:SOLUTIONS
319036
Which of the following pair of solutions is isotonic?
1 \({\rm{0}}{\rm{.001M}}{\mkern 1mu} {\mkern 1mu} {\rm{A}}{{\rm{l}}_{\rm{2}}}{\left( {{\rm{S}}{{\rm{O}}_{\rm{4}}}} \right)_{\rm{3}}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.01M}}{\mkern 1mu} {\mkern 1mu} {\rm{BaC}}{{\rm{l}}_{\rm{2}}}\)
2 \({\rm{0}}{\rm{.001M}}{\mkern 1mu} {\mkern 1mu} {\rm{CaC}}{{\rm{l}}_{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.001M}}{\mkern 1mu} {\mkern 1mu} {\rm{A}}{{\rm{l}}_{\rm{2}}}{\left( {{\rm{S}}{{\rm{O}}_{\rm{4}}}} \right)_{\rm{3}}}\)
3 \({\rm{0}}{\rm{.01M}}{\mkern 1mu} {\mkern 1mu} {\rm{BaC}}{{\rm{l}}_{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.001M}}{\mkern 1mu} {\mkern 1mu} {\rm{CaC}}{{\rm{l}}_{\rm{2}}}\)
4 \({\rm{0}}{\rm{.01M}}{\mkern 1mu} {\mkern 1mu} {\rm{BaC}}{{\rm{l}}_{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.015}}{\mkern 1mu} {\mkern 1mu} {\rm{M}}{\mkern 1mu} {\mkern 1mu} {\rm{NaCl}}\)
Explanation:
Isotonic solutions are those which have same osmotic pressure at a given temperature.
\({\rm{For}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.01M}}{\mkern 1mu} {\mkern 1mu} {\rm{BaC}}{{\rm{l}}_{\rm{2}}}{\rm{,i = 3}}\)
\(\pi = iCRT\)
\({\rm{ = 3 \times 0}}{\rm{.01RT = 0}}{\rm{.03RT}}\)
\({\rm{For}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.015M}}{\mkern 1mu} {\mkern 1mu} {\rm{NaCl,i = 2}}\)
\(\therefore {\mkern 1mu} {\mkern 1mu} {\rm{\pi = 2 \times 0}}{\rm{.015RT = 0}}{\rm{.03RT}}\)
Therefore, \({\rm{0}}{\rm{.01M}}{\mkern 1mu} {\mkern 1mu} {\rm{BaC}}{{\rm{l}}_{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\rm{and}}{\mkern 1mu} {\mkern 1mu} {\rm{0}}{\rm{.015M}}{\mkern 1mu} {\mkern 1mu} {\rm{NaCl}}\) are isotonic.