Short Answer TypeChoose 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?
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]
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