An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?
(a) Baking powder
(b) Lime
(c) Ammonium hydroxide solution
(d) Hydrochloric acid
Answer: (d)
Since, the aqueous solution turns red litmus solution blue. So, it is a basic compound. An acid solution would reverse the change. That is would turn blue litmus solution to red