Question

While performing the magic trick, Alex arranged different solutions and observed the effect of various indicators on them. The observations are:​
I. Turmeric solution will turn red in solutions 1, 3 and 4.​
II. China rose will turn dark pink in solution 2.​
III. Red litmus will turn blue in solutions 1, 2 and 4.​
IV. Phenolphthalein will turn colourless in solutions 2 and 3.
Identify the correct observations.​

• A. I, III and IV only​
• B. I and II only​
• C. I, II and IV only​
• D. I and III only​

Answer 1

The correct option is B I and II only​

$\bullet$ Out of the given solutions, solution 1 is a soap solution that contains sodium hydroxide, solution 3 is a window cleaner that contains ammonium hydroxide and solution 4 is lime water i.e. calcium hydroxide. These all are basic in nature. On the other hand, solution 2 is vinegar that contains acetic acid. So, it is acidic in nature.
$\bullet$ Turmeric solution turns red in solutions 1, 3 and 4 as these are basic. So, statement I is correct.
$\bullet$ China rose will turn dark pink in solution 2 because it is acidic. Thus, statement II is correct.
$\bullet$ Red litmus will turn blue in basic solutions 1, 3 and 4 but does not change the colour in acidic solution i.e, solution 2. So, statement III is incorrect.
$\bullet$ Phenolphthalein remains colourless in acidic solution i.e, solution 2 whereas turns pink in basic solutions 1, 3 and 4. Therefore, statement IV is incorrect.