Question

A 55-kg woman has 7.5 × 10^−3 mol of hemoglobin (molar mass = 64,456 g/mol) in her blood. How many hemoglobin molecules is this? What is this quantity in grams?

a) 2.64 × 10^22 molecules, 4.83 g

b) 4.83 × 10^22 molecules, 2.64 g

c) 1.32 × 10^23 molecules, 8.16 g

d) 8.16 × 10^23 molecules, 1.32 g

Answer 1

To determine the number of hemoglobin molecules and the quantity in grams, you need to use Avogadro's number and the molar mass. The number of molecules is 4.51 x 10^20, and the quantity in grams is 483.42 g. The correct option is a.

Step-by-step explanation:

To determine the number of hemoglobin molecules, we need to use Avogadro's number, which states that there are 6.022 × 10^23 molecules in 1 mole of any substance. First, we calculate the number of moles of hemoglobin using the given mass and molar mass:

Number of moles = Mass / Molar mass

Number of moles = 7.5 × 10^−3 mol

Next, we convert the moles of hemoglobin to molecules:

Number of molecules = Number of moles × Avogadro's number

Number of molecules = 7.5 × 10^−3 mol × 6.022 × 10^23 molecules/mol

Number of molecules = 4.5135 × 10^20 molecules

Finally, to calculate the quantity in grams, we multiply the number of moles by the molar mass:

Quantity in grams = Number of moles × Molar mass

Quantity in grams = 7.5 × 10^−3 mol × 64,456 g/mol

Quantity in grams = 483.42 grams. The correct option is a.