Question

The molecular weight of phosphoric acid, H3 PO4, is 97.99 g/mol. What is the mass, in grams, of 0.00948 mol of phosphoric acid?

a) 0.92 g
b) 0.93 g
c) 0.94 g
d) 0.95 g

Answer 1

The mass of 0.00948 mol of phosphoric acid is calculated by multiplying the number of moles by the molecular weight of phosphoric acid, which gives 0.929 g, rounded to 0.93 g.

Step-by-step explanation:

To calculate the mass in grams of 0.00948 mol of phosphoric acid (H3PO4), with a molecular weight of 97.99 g/mol, you multiply the number of moles by the molecular weight. The molecular weight is the conversion factor from moles to grams.

Here is the calculation:

• Number of moles of phosphoric acid = 0.00948 mol
• Molecular weight of phosphoric acid = 97.99 g/mol
• Mass of phosphoric acid = Number of moles × Molecular weight
• Mass = 0.00948 mol × 97.99 g/mol
• Mass = 0.929 g (rounded to three significant figures)

The mass of 0.00948 mol of phosphoric acid is 0.929 g, which rounds to 0.93 g when considering answer choices to the nearest hundredth.