Which solution is more concentrated: a 10% (w/v) NaOH solution or a 1 M NaOH solution?

• A. Both solutions have the same concentration
• B. 10% (w/v) NaOH solution
• C. Cannot be determined without more information
• D. 1 M NaOH solution

Answer: (B)

Verified step by step guidance

1. Understand the meaning of the given concentrations: 10% (w/v) means 10 grams of NaOH per 100 mL of solution, while 1 M means 1 mole of NaOH per liter of solution.
2. Convert the 10% (w/v) concentration into molarity to compare both solutions on the same basis. Use the molar mass of NaOH, which is approximately 40 g/mol.
3. Calculate the number of moles of NaOH in 100 mL of the 10% (w/v) solution using the formula: \(\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\).
4. Convert the volume from 100 mL to liters (0.1 L) to find molarity using the formula: \(\text{Molarity} = \frac{\text{moles}}{\text{volume (L)}}\).
5. Compare the molarity of the 10% (w/v) solution with the given 1 M solution to determine which is more concentrated.