Answer :
Final answer:
To find the molarity of the urea solution, calculate the moles of urea, the total mass of the solution, and then divide the moles of urea by the volume of the solution in liters, leading to a molarity of 6.38 M.So,option D. 6.38 M is correct.
Explanation:
The question asks to determine the molarity of a urea solution. First, we calculate the molar mass of urea (NH₂)2CO, which is 14(2) + 1(4) + 12 + 16 = 60 g/mol. Therefore, the number of moles of urea is 16.0 g / 60 g/mol = 0.267 mol. The total mass of the solution is 16.0 g + 38.6 g = 54.6 g. Given the density of the solution is 1.30 g/mL, the volume of the solution can be found: 54.6 g / 1.30 g/mL = 42.0 mL = 0.042 L. Finally, the molarity (M) is calculated by dividing the moles of urea by the volume of the solution in liters: 0.267 mol / 0.042 L = 6.38 M.
