Question

A drop of solution (volume 0.05 mL) contains 3.0 × 10–6 moles of H+. If the rate constant of disappearance of H+ is 1.0 × 107 mole litre–1 sec–1. How long would it take for H+ in drop to disappear :

• A. 6 × 10–8 sec
• B. 6 × 10–7 sec
• C. 6 × 10–9 sec
• D. 6 × 10–10 sec

Answer 1

Answer: (C)

6 × 10–9 sec

Answer 2

Time Total for drop to disappears

$\frac{3.0 \times 10^{- 6}}{\left( 0.05 \times 10^{- 3} \right) \times 1.0 \times 10^{7}} = t_{100\%} \Rightarrow t_{100\%} = 6 \times 10^{- 9}\sec$