How many molecules of sucrose are in 0.5 L of a 1 molar solution of sucrose?

1 molar solution means that there are 1 mole of solute per litre of solution.
1 mole of any substance means that there are the Avogadro's constant number of particles, that is 6.02x10^23 particles.

Can you find the answer now?
1. Find the number of moles of sucrose in the 0.5 L solution.
2. From the number of moles, you can find the number of molecules.