How many grams of O are found in 1.00 × 10² g of K₂Cr₂O₇?

Question

Quizplus · Accepted Answer

- Calculate the molar mass of K2Cr2O7:
2(K) + 2(Cr) + 7(O) = 294.18 g/mol
- Calculate the number of moles of K2Cr2O7:
1.00 × 10^12 g / 294.18 g/mol = 3.40 × 10^9 mol
- Calculate the number of moles of O:
3.40 × 10^9 mol x 7 O/mol = 2.38 × 10^10 mol O
- Calculate the mass of O:
2.38 × 10^10 mol x 16.00 g/mol = 3.81 × 10^11 g ≈ 38.1 g
Therefore, the answer is B.

How Many Grams of O Are Found in 1