Chemistry Questions

Valency of an element depends on which of the following?

I. Number of losing electron

II. Number of gaining electron

III. Number of sharing electron

Which is not a green house gas in the following?

Plaster of Paris ______.

I. changes into gypsum on mixing with water

II. is CaSO4.2H2O

III. is used for decoration

Which of the following statements is/are true or false?

Statements :

A) H2S burns in air to give H2O and SO2

B) The decomposition of Ferrous Sulphate into Fe2O3, SO2 and SO3 occurs in the presence of heat.

Fill in the blank with the most appropriate option.

Ethanol is denatured to ___.

Out of all known elements, the minimum number is of ______.

Generally covalently bonded molecules ______.

I. have high boiling and melting point as compare to ionically bonded molecules

II. poor conductors of electricity

III. have weak intermolecular force

Washing soda is used ______.

I. for removing permanent hardness of water

II. for disinfecting drinking water

III. as a cleaning agent for domestic purpose