Name the following:
From the list of characteristic given below select the five which are relevant to metals and their compounds.
GIVE SCIENTIFIC REASONS
Sodium is stored under kerosene.
Gold and silver are used to make jewellery.
Calcium floats over water during the reaction with water.
Ionic compounds have high melting and boiling points
Tarnished copper utensils are cleaned with lime juice or tamarind.
Copper is exposed to air.
Reason for use of fused cryolite (Na3AlF6) along with fluorspar (CaF2) which is added to the electrolytic mixture containing pure alumina.
Electrolysis of active metals like Na, K, Al is not carried out by using aqueous solution of their chloride.
ANSWER THE FOLLOWING IN DETAIL
Sudha dipped a copper coin in a solution of silver nitrate. After some time she saw the silver shine on the coin. Why? Give the balanced chemical equation for the same.
Metal A has electronic configuration of (2,8,1) and metal B has (2,8,8,2) which is more reactive. Identify these metals and vie their reactions with dil HCl.
To obtain (zinc) Zn from zinc sulphide two chemical reaction are involved
When steam is passed over aluminium.
Extraction of copper from its sulphide ore.
When magnesium reacts with hot water.
What happens when aluminium oxide dissolves in aqueous sodium hydroxide?
In the extraction of aluminium
Write two methods of preventing rusting of iron.
What is an alloy? Give two examples with their chemical composition.
Arrange the following metals in the decreasing order of chemical reactivity, Cu, Mg, Fe, Na, Ca, Zn.
Explain the formation of an ionic compound between metal and a non – metal by transfer of electrons with Mg as the metal and Cl as a non – metal to illustrate your answer.
An element X on reacting with oxygen forms an oxide X2O. This oxide dissolves in water and turns red litmus blue. State whether element X is a metal or a non – metal. Explain with proper example.
Explain the properties of ionic compounds.