Question

Choose a false statement regarding the properties of sodium hydroxide.

• A. It is highly water soluble.
• B. It absorbs atmospheric \(\text{CO}_2\) to form \(\text{Na}_2\text{CO}_3\).
• C. the solution of NaOH turns blue litmus red.
• D. NaOH is a white deliquescent solid.

Hint:

NaOH is a strong base, so its solution turns red litmus blue, not blue litmus red.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
We must find the statement that is not true. Sodium hydroxide is a strong base and a white solid, so we check each statement against that.

Step 2: Check statement (A)
NaOH dissolves very easily in water and gives out heat while dissolving. So (A) is true.

Step 3: Check statement (B)
NaOH absorbs \(\text{CO}_2\) from air and forms sodium carbonate:
\[ 2\text{NaOH}+\text{CO}_2\to\text{Na}_2\text{CO}_3+\text{H}_2\text{O} \]
So (B) is true.

Step 4: Check statement (C)
A basic solution turns red litmus blue. Blue litmus turns red only in an acidic solution. NaOH solution is strongly basic, so it cannot turn blue litmus red. So (C) is FALSE.

Step 5: Check statement (D)
NaOH is a white, translucent, deliquescent solid that absorbs moisture from air. So (D) is true.

Final Answer:
Statement (C) is false because a basic NaOH solution does not turn blue litmus red. \[ \boxed{\text{(C)}} \]