Q1.
Can you now reflect — which solution is more concentrated; 2 spoons of salt in 100 mL of water or 4 spoons of salt in 50 mL of water?
Answer
The 4 spoons in 50 mL — and by a factor of four.
Concentration means the amount of solute in a fixed quantity of solution, so bring both to the same volume before comparing.
First solution: 2 spoons in 100 mL
Second solution: 4 spoons in 50 mL = 4 × 2 spoons in 2 × 50 mL = 8 spoons in 100 mL
8 spoons per 100 mL ÷ 2 spoons per 100 mL = 4 times as concentrated
Second solution: 4 spoons in 50 mL = 4 × 2 spoons in 2 × 50 mL = 8 spoons in 100 mL
8 spoons per 100 mL ÷ 2 spoons per 100 mL = 4 times as concentrated
Why it happens: You cannot compare 2 with 4 directly, because the two amounts of salt are shared among different amounts of water. The second solution has twice as much salt spread through half as much water — 2 × 2 = 4 times as crowded with salt particles. The first is the dilute one, the second the concentrated one.
Tip: Dilute and concentrated are relative terms — they only tell you which of two solutions has more solute per unit volume. They say nothing about whether either one is saturated.