Final answer:
To find the molarity of urea in the urine sample, convert the amount of urea to grams and the volume of the sample to liters, calculate the moles of urea based on its molar mass, and divide by the volume in liters. The molarity of the sample is approximately 0.0083195 M.
Step-by-step explanation:
To calculate the molarity of urea in the given 20 mL sample of human urine, we first need to convert milligrams to grams, and milliliters to liters since molarity is defined as moles of solute per liter of solution.
Step 1: Convert 10 mg of urea to grams:
10 mg × (1 g / 1000 mg) = 0.01 g
Step 2: Convert 20 mL to liters:
20 mL × (1 L / 1000 mL) = 0.02 L
Step 3: Calculate moles of urea using its molar mass:
0.01 g × (1 mol / 60.1 g) = 0.00016639 mol
Step 4: Calculate molarity of the urea solution:
0.00016639 mol / 0.02 L = 0.0083195 M
Thus, the molarity of urea in the urine sample is approximately 0.0083195 M.