Question

Four solutions $A,B,C$ and $D$ when tested with universal indicator showed $pH$ as $4,11,7$ and $9$ respectively. Which solution is weakly alkaline?

• A. $A$
• B. $B$
• C. $C$
• D. $D$

Answer 1

The correct option is D $D$

Four tubes $A,B,C$ and $D$ have solutions with $pH=4,11,7$ and $9$. Tubes $B$ and $D$ are alkaline in nature having more hydroxide ions, so more hydrogen ions are needed to neutralize the effect, tube $D$ with $pH$ value $9$ is weakly alkaline as compared to $B$ which has higher $pH$ value. Greater the $pH$ value, greater the alkalinity of the solution.
The $pH$ can be arranged in the increasing order of the concentration of hydrogen ions as : $11<9<7<4$.