Question

Lalita has taken sulphur powder $\left(P\right)$ in a deflagrating spoon, burnt it and put it in a gas jar. Then she removed the spoon and added water. In another experiment, she has taken water in one beaker and added a small piece of sodium $\left(Q\right)$. After some time, she took both the solutions and checked them with litmus paper. What result would she expect?

• A. In case $P$; blue to red, in case $Q:$ red to blue
• B. In both cases, $P$and$Q:$blue to red
• C. In case $P:$ red to blue, in case $Q:$ blue to red
• D. In both cases, $P$and$Q:$ red to blue

Answer 1

The correct option is A In case $P$; blue to red, in case $Q:$ red to blue

When sulphur burns in the presence of air,

$S+O_2\to \underset{\left(P\right)}{S{O}_2}+H_{2}O\to \underset{Acidic}{H_{2}S{O}_3}$

$2Na+2H_{2}O\to \underset{\left(Q\right)}{2NaOH}+H_2$

Litmus paper used to identification of acidic or basic nature of any solution.

Red to red - An acidic solution

Red to blue - A basic solution

P is acidic in nature so blue to red.

Q is basic in nature so red to blue.