Question

If 0.870 mol of liquid Br2 and 720 mL of 0.958 M aqueous NaI are reacted stoichiometrically according to the balanced equation, how many grams of solid I2 are produced?

2NaI(aq) + Br2(l) → 2NaBr(aq) + I2(s)

help please. :)

Answer 1

A limiting reagent problem.
1. Write the balanced equation.
2. You have Br already in mols.
3. Convert NaI to moles. moles = M x L.
4a. Using the coefficients in the balanced equation, convert moles Br2 to moles I2.
4b. Using the same procedure, convert moles NaI to moles I2.
4c. It is likely that the moles I2 produced will not be the same from 4a and 4b. Obviously, one of them in not correct. The correct answer in limiting reagent problems is ALWAYS the smaller value.
5. Now convert moles I2 from 4c to grams. g = moles x molar mass.