Question

The limiting reactant, O2, can form up to 2.7 mol Al2O3. What mass of Al2O3 forms?

Answer 1

Answer:

280 g Al₂O₃

Explanation:

To find the mass, you need to multiply the given value by the molar mass. This will cause the conversion because the molar mass exists as a ratio; technically, the ratio states that there are 101.96 grams per every 1 mole Al₂O₃. It is important to arrange the ratio in a way that allows for the cancellation of units. In this case, the desired unit (grams) should be in the numerator. The final answer should have 2 sig figs to reflect the given value (2.7 mol).

Molar Mass (Al₂O₃): 101.96 g/mol

2.7 moles Al₂O₃          101.96 g
------------------------  x  -------------------  = 275 g Al₂O₃  = 280 g Al₂O₃
                                     1 mole