A) 69.60
B) 49.59
C) 59.60
D) 108.30.
Correct Answer: A
Solution :
Relative lowering of vapour pressure is given by: \[\frac{{{P}^{0}}-{{P}_{s}}}{{{P}^{0}}}={{X}_{A}};{{X}_{A}}=\] mole fraction of solute \[{{P}^{0}}\]= vapour pressure of pure solvent \[{{P}_{s}}\] = vapour pressure of solution \[\Rightarrow \] \[\frac{39.08/78}{39.08/78+2.175/{{M}_{A}}}\]\[\Rightarrow \]\[{{M}_{A}}=69.60\]You need to login to perform this action.
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