An aqueous solution of glucose boils at `100.01^@C.` The molal elevation constant for water is `"0.5 K mol"^(-1)" kg".` What is the number of glucose molecules in the solution containing 100 g water?

Options

A. `2.4 xx 10^(21)`
B. `2.4 xx 10^(20)`
C. `1.2 xx 10^(21)`
D. `1.2 xx 10^(21)`

Answer

C

Explanation

`triangleT=(1000 K_(b) w)/(mW)`
`0.01 =(1000 xx 0.5 xx w)/(180 xx 100) w=0.36g`
180g glucose contains `=6.023 xx 10^(23) ` molecules
0.36g glucose contains `=(6.023 xx 10^(23) xx 0.36)/(180)=1.2 xx 10^(21)" molecules"`