* Moles and Mass: 1 mole of sucrose *always* weighs 342.12 grams. This is its molar mass. It doesn't change based on how much water is added.
* Solutions: The addition of water creates a solution (sucrose dissolved in water). The amount of water you add determines the concentration of the solution, not the mass of the sucrose itself.
To calculate the amount of sucrose in 0.2 moles:
1. Molar mass of sucrose: 342.12 g/mol
2. Multiply moles by molar mass: 0.2 moles * 342.12 g/mol = 68.424 grams of sucrose
Calculating the amount of water needed to make a solution:
To figure out how much water you'd need to make a solution with 0.2 moles of sucrose, you'd need to know the desired concentration (e.g., molarity).
Example:
If you want a 0.1 M (molar) solution of sucrose, you would need:
1. Calculate volume: Molarity (M) = moles/volume (L)
0.1 M = 0.2 moles / volume (L)
Volume = 2 liters (2000 mL)
2. Subtract the volume of sucrose: Since sucrose contributes a negligible volume, you'd use approximately 2000 mL of water.
Key takeaway: The amount of sucrose in 0.2 moles is always 68.424 grams. The amount of water you add determines the concentration of the resulting solution.
