Multiple Choice
An aqueous solution of fructose (MM = 180.2 g/mol) has a molality of 4.87 m and a density of 1.30 g/mL. What is the molarity of fructose in the solution?
6. Chemical Quantities & Aqueous Reactions
Molarity
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Calculate the mass of malonic acid, CH₂(COOH)₂, required to make 25 mL of a solution that is 0.15 M in malonic acid.
A
0.75 g
B
0.39 g
C
0.25 g
D
0.15 g
Verified step by step guidance1
First, understand that molarity (M) is defined as moles of solute per liter of solution. Here, you need to find the mass of malonic acid required for a 0.15 M solution in 25 mL.
Convert the volume of the solution from milliliters to liters. Since 1 L = 1000 mL, divide 25 mL by 1000 to get the volume in liters.
Use the molarity formula: \( M = \frac{n}{V} \), where \( n \) is the number of moles and \( V \) is the volume in liters. Rearrange the formula to solve for \( n \): \( n = M \times V \). Substitute the values for molarity and volume to find the number of moles of malonic acid needed.
Calculate the molar mass of malonic acid, CH₂(COOH)₂. Add the atomic masses of all atoms in the formula: 2 carbon (C), 4 hydrogen (H), and 4 oxygen (O) atoms. Use the periodic table for atomic masses: C = 12.01 g/mol, H = 1.01 g/mol, O = 16.00 g/mol.
Finally, use the formula \( ext{mass} = ext{moles} \times ext{molar mass} \) to find the mass of malonic acid required. Multiply the number of moles calculated in step 3 by the molar mass calculated in step 4.
Related Videos
Related Practice
