If 10 grams of NaOH is dissolved in 500 mL of solution, what is the molality of the solution? (Molar mass of NaOH = 40 g/mol)
Practice Questions
1 question
Q1
If 10 grams of NaOH is dissolved in 500 mL of solution, what is the molality of the solution? (Molar mass of NaOH = 40 g/mol)
0.5 m
1 m
2 m
0.25 m
Moles of NaOH = 10 g / 40 g/mol = 0.25 moles. Mass of solvent (water) = 0.5 kg. Molality (m) = moles of solute / kg of solvent = 0.25 moles / 0.5 kg = 0.5 m.
Questions & Step-by-step Solutions
1 item
Q
Q: If 10 grams of NaOH is dissolved in 500 mL of solution, what is the molality of the solution? (Molar mass of NaOH = 40 g/mol)
Solution: Moles of NaOH = 10 g / 40 g/mol = 0.25 moles. Mass of solvent (water) = 0.5 kg. Molality (m) = moles of solute / kg of solvent = 0.25 moles / 0.5 kg = 0.5 m.
Steps: 6
Step 1: Identify the mass of NaOH given in the problem, which is 10 grams.
Step 2: Find the molar mass of NaOH, which is given as 40 g/mol.
Step 3: Calculate the number of moles of NaOH using the formula: moles = mass (g) / molar mass (g/mol). So, moles of NaOH = 10 g / 40 g/mol = 0.25 moles.
Step 4: Identify the volume of the solution, which is 500 mL. Convert this volume to kilograms of solvent (water). Since 1 L of water is approximately 1 kg, 500 mL is 0.5 kg.
Step 5: Use the formula for molality (m), which is moles of solute / kg of solvent. Here, molality = 0.25 moles / 0.5 kg.
Step 6: Calculate the molality: 0.25 moles / 0.5 kg = 0.5 m.
