Carbon and its Compounds — Science STD 10 — Question

Select the incorrect statement.
a. The formula of the compound is calcium sulphate dihydrate.
b. When mixed with water and left for half an hour, this compound sets into a hard mass.
c. If heated at higher temperature, the compound becomes dehydrated and is called dead burnt plaster.
d. Both (a) and (b)

An alkyne has seventy five carbon atoms in its molecule. The number of hydrogen atoms in its molecule will be:

Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?

Which of the following is not the property of non - metals?

Buckminsterfullerene is an allotropic form of:

1. Phosphorus.
2. Sulphur.
3. Carbon.
4. Tin.

Which of the following is not a mineral acid?

1. Hydrochloric acid.
2. Citric acid.
3. Sulphuric acid.
4. Nitric acid.

Some crystals of copper sulphate were dissolved in water. The colour of the solution obtained would be:

In the experiment for determining the percentage of water absorbed by raisins, we do the final weighing of the raisins after keeping them dipped in water for about one hour. For the accuracy of the result, the extra water from the surface of the soaked raisins is removed by:

An iron nail was suspended in CuSO₄ solution and kept for a while the solution is:

Match the following with the correct response:

Column A	Column B
(i) Copper is used in electrical appliances	(a) Hydrogen sulphide
(ii) Sodium is very reactive	(b) Good conductor
(iii) Silver is tarnished	(c) Graphite
(iv) A non-metal and a good conductor	(d) Stored in kerosene