You have 1 liter of a freshly prepared 0.1 m sucrose (molecular mass 342) solution, which means

The answer is that it means there are 6.02 x 10²² molecules of sucrose are present in the solution.

Because 1 mole of solution contains Avogadro's number of molecules in a solution that is 6.02 x 10²³ molecule.

So.

0.1 m sucrose solution = 0.1 x 6.02 x 10²³ = 6.02 x 10²² molecules