Write the chemical formula of the calcium carbonate.

$\mathrm{A}: {\mathrm{Ca}}_2{\mathrm{CO}}_3 \mathrm{B}: {\mathrm{CaSO}}_4 \mathrm{C}: {\mathrm{CaCO}}_3 \mathrm{D}: {\mathrm{Ca}}_2{\mathrm{SO}}_4$ (Enter your correct answer as $\mathrm{A}, \mathrm{B}, \mathrm{C} \mathrm{or} \mathrm{D}$)

Which gas is formed when calcium carbonate reacts with acids?

What is the name of an aqueous solution of ${\mathrm{CO}}_2$ gas?

Graphite, which is an allotrope of carbon, is a conductor of electricity. But diamond, another allotrope is not a conductor of electricity. Why?

Write the structure of a straight chain and a ring hydrocarbon having four carbon atoms.

Arrange the objects as shown in the figure and conduct the experiment. Based on your observation, what is the conclusion that you reach at ?

Lighted candles of different lengths are arranged in a trough as shown in the figure. Pour a saturated solution of sodium bicarbonate (baking soda) into the trough. Add a little vinegar to the solution. What do you observe? Give reasons for the observations.

Prepare a write-up, on the topic "Importance of the organic chemistry".