What is the mass in grams of 0.257 mol of sucrose (c12h22o11)?

87.894 grams.

Explanation:

So we know that the mass of the carbon is 12g, the Mass of the Hydrogen is  1g and the Mass of the Oxygen is 16g. Given, Chemical Formula of the Sucrose C₁₂H₂₂o₁₁ we can calculate the molar mass by performing the following operation:

Molar Mass = 12 × 12 + 1 × 22 + 16 × 11 = 144 + 22 + 176 = 342 g/mole

So if we need to know the mass in grams of 0.257 mol, then we have to:

342 g/mole * 0.257 mol = 87.894 grams.