Surface Chemistry Question 4
Question 4 - 29 January - Shift 1
Which of the following salt solutions would coagulate the colloid soloution formed when $FeCl_3$ is added to $NaOH$ solution, at the fastest rate?
(1) $10 mL$ of $0.2 mol dm^{-3} AlCl_3$
(2) $10 mL$ of $0.1 mol dm^{-3} Na_2 SO_4$
(3) $10 mL$ of $0.1 mol dm^{-3} Ca_3(PO_4)_2$
(4) $10 mL$ of $0.15 mol dm^{-3} CaCl_2$
Show Answer
Answer: (1)
Solution:
Sol. Formed is negatively charged solution, therefore $Al^{3+}$ has highest coagulating power
