In a dilution of 2 mL soln to 8 mL solvent, which pair of ratios correctly represents solute to total volume and solute to solvent?

In a dilution of 2 mL soln to 8 mL solvent, which pair of ratios correctly represents solute to total volume and solute to solvent?

• A. 2:8, 2:10
• B. 10:2, 8:2
• C. 2:10, 2:8
• D. 8:2, 10:2

Answer: (C)

When you dilute, you compare the amount of solute to both the total volume and to the solvent used. Here, 2 mL of solute is mixed with 8 mL of solvent, so the total volume becomes 2 + 8 = 10 mL. Solute to total volume is 2 mL solute : 10 mL total, i.e., 2:10 (which simplifies to 1:5 if you prefer). Solute to solvent is 2 mL solute : 8 mL solvent, i.e., 2:8 (which simplifies to 1:4). So the correct pair is 2:10 for solute to total and 2:8 for solute to solvent. The other options either mix up the denominators or swap the ratios, not representing the two defined relationships in the same order.

When you dilute, you compare the amount of solute to both the total volume and to the solvent used. Here, 2 mL of solute is mixed with 8 mL of solvent, so the total volume becomes 2 + 8 = 10 mL.

Solute to total volume is 2 mL solute : 10 mL total, i.e., 2:10 (which simplifies to 1:5 if you prefer).

Solute to solvent is 2 mL solute : 8 mL solvent, i.e., 2:8 (which simplifies to 1:4).

So the correct pair is 2:10 for solute to total and 2:8 for solute to solvent. The other options either mix up the denominators or swap the ratios, not representing the two defined relationships in the same order.