The density of water is 1.00 g/mL at 4°C.How many water molecules are present in 6.25 mL of water at this temperature? (N_A = 6.022 × 10²³ mol⁻¹)

Question

Quizplus · Accepted Answer

To calculate the number of water molecules, we need to use the formula:

number of molecules = (density) x (volume) x (Avogadro's number) / (molar mass of water)

We are given the density of water, which is 1.00 g/mL, and the volume of water, which is 6.25 mL. The molar mass of water is 18.015 g/mol, and Avogadro's number is 6.022 x 10^23 molecules/mol.

Substituting these values into the formula, we get:

number of molecules = (1.00 g/mL) x (6.25 mL) x (6.022 x 10^23 molecules/mol) / (18.015 g/mol)
number of molecules = 2.091 x 10^23 molecules

Therefore, the answer is choice C, 2.09 x 10^23 molecules.

The Density of Water Is 1