J.R. S. answered 06/15/19
Ph.D. University Professor with 10+ years Tutoring Experience
Cr(OH)3 + NaOH ==> NaCrO2 + 2H2O
Moles Cr(OH)3 present = 7.40 g x 1 mole/103 g = 0.0718 moles
Moles NaOH present = 7.60 g x 1 mol/40 g = 0.0543 moles
Limiting reactant = NaOH since mole ratio in balanced reaction is 1:1 and there is less NaOH than Cr(OH)3
Theoretical yield of NaCrO2 = 0.0543 moles NaOH x 1 mole NaCrO2/mole NaOH x 107 g/mole = 5.81 g