WCH11 October 2022

2​​ Which mixture results in a precipitation reaction?

A-dilute sulfuric acid and potassium hydroxide solution

B-iron and calcium chloride solution

C-chlorine water and potassium bromide​​ solution

D-silver nitrate solution and potassium bromide solution

(Total for Question 2 = 1 mark)

ANSWER

D - silver nitrate solution and potassium bromide solution

Analysis of Option/Explanation

Option A

H2SO4​​ + 2KOHK2SO4​​ + 2H2O, the said reaction is a​​ neutralization reaction​​ which has taken place between an acid and Alkali resulting in formation of Salt and water.

Option B

Fe + CaCl2No reaction, the reaction doesnot take place as “Fe” is lower in the electrochemical series when compared with “Ca”,​​ hence not able to displace it.

Option C

Cl2​​ + 2KBr2KCl + Br2; the said reaction is a neutralization reaction in which the “Cl” displace “K” from its compound resulting in formation of potassium chloride and leaving​​ Bromine alone. This happens because Chlorine is above the potassium in electrochemical series.

Option D)

AgNO3​​ + KBrKNO3​​ +​​ AgBr, the said reaction is a precipitation reaction in which green Ag Br precipitate is formed.