Arrange the following as per the instructions given in the brackets:
iv) Cl,F, Br, I(increasing the order of electron affinity).
Choose the most appropriate answer from the following list of oxides which fit the description. Each answer may be used only once:
[SO2,Al2O3,SiO2,MgO,CO,Na2O]
i) A basic oxide
ii) An oxide which dissolves in water forming an acid
iii) An amphoteric oxide
iv) A covalent oxide of a metalloid.
Choose the most appropriate answer for the following:
Bonding in this molecule can be understood to involve coordinate bonding.
A) Carbon tetrachloride
B) Hydrogen
C) Hydrogen chloride
D) Ammonium chloride
Give appropriate scientific reason for the following statement:
Carbon tetrachloride does not conduct electricity.
Answer the following question:
Explain the bonding in methane molecule using electron dot structure.
Element X is a metal with a valency 2, Y is a non-metal with a Valency 3.
i) write an equation to show how Y forms an ion.
ii) If Y is diatomic gas, write an equation for the direct combination of X and Y to form a compound.
An element L consists of molecules.
i) What types of bonding is present in the particles that make up L?
ii) When L is heated with iron metal, it forms a compound FeL. What chemical term would you use to describe the change undergone by L?
i) Covalent bonding is present in the particle.
ii) Reduction
The following table shows the tests a student performed on four different aqueous solutions which are X, Y, Z and W. based on the observation provided identify the cation present:
Chemical Test |
Observation |
Conclusion |
To solution X, ammonium hydroxide is added in minimum quantity first and then in excess. |
A dirty white precipitate is formed which dissolves in excess to form a clear solution |
|
To solution Y ammonium hydroxide is added in minimum quantity first and then excess. |
A pale blue precipitate is formed which dissolves in excess to form a clear inky blue solution |
|
To solution W a small quantity of sodium hydroxide solution is added and then in excess. |
A white precipitate is formed which remains insoluble. |
|
To a salt Z calcium hydroxide solution is added and then heated. |
A pungent smelling gas turning moist red litmus paper blue is obtained. |
|
Choose the most appropriate answer for the following:
Which of the following would weigh the least?
A) 2 gram atoms of nitrogen.
B) 1 mole of silver
C) 22.4 Litres of oxygen gas at 1 atomspheric pressure and 273K
D) 6.02 x 1023 atoms of carbon.
[ atomic masses : Ag (108, N =14, O=16, C=12]