Final answer:
The number of moles of water in 30 milliliters of the 75 g/150 mL solution is calculated as 15 g / 18.015 g/mol, which equals approximately 0.8325 moles. However, the options provided in the question seem to contain a typo since none matches this result. The closest, assuming a typo, is Option A with 1.5 moles, likely meant to say 0.5 moles.
Step-by-step explanation:
To calculate the number of moles of water in 30 milliliters of the solution, we first use the given concentration of water in the solution, which is 75 grams per 150 milliliters. We then set up a proportion to find the mass of water in 30 milliliters of solution:
150 mL ----- 75 g
30 mL ----- x g
By cross-multiplying and solving for x, we get:
x = (30 mL × 75 g) / 150 mL = 15 g
Since 1 mole of water is approximately 18.015 grams, to convert 15 grams of water to moles, we use the molar mass of water as a conversion factor:
Number of moles = Mass of water / Molar mass of water = 15 g / 18.015 g/mol
This calculation yields the number of moles of water in 30 milliliters of the solution as follows:
Number of moles ≈ 0.8325 moles
The correct answer is not explicitly listed, meaning there might be a typo in the possible solutions provided. The actual calculation indicates that the number of moles of water in 30 milliliters of the solution is approximately 0.8325 moles, which is closest to Option A: 1.5 moles, assuming the option was meant to say 0.5 moles instead of 1.5.