Chem 8

A reaction in which two or more substances combine to form a single substance.

• Decomposition reaction

• Displacement reaction

• Synthesis reaction

• Oxidation reaction

The metals that reacts vigorously with cold water to form hydroxide and liberates hydrogen gas

• K, and Na

• K, Na and Ca

• Na and Ca

• K and Mg

The diagram given is for the laboratory preparation of

• carbon dioxide

• hydrogen

An atom requires two electrons to attain a stable electronic configuration. Which of the following elements can this atom react with to attain stability? 

    Neon, Chlorine, Helium and Calcium

1.   

• 1. Only Neon and Calcium 

• 1. Only Calcium 

• 1. Only Chlorine and Helium 

• 1. All of the above elements   

How many electrons are shared by each nitrogen atom forming a covalent bond

• 3

• 6

Balance the following chemical equations

Write the chemical formula for the following with the necessary steps:

i. Barium sulphate

ii. Calcium bromide

iii. Magnesium nitrate

iv. Aluminium chloride

v. Ammonium phosphate

The two images shown are allotropes of carbon.Identify the two crystalline form of carbon

• graphite and diamond

• diamond and graphite

• gas carbon and coke

• lamp black and wood charcoal

• The property by virtue of which a compound loses its water of crystallization on exposure to dry air and crumbles into an amorphous powder.

• DELIQUESCENCE

  
  

• HYGROSCOPY

  
  

• EFFLORESCENCE

  
  

Bicarbonates of Ca and Mg causes

• Temporaray hardness of water

• permanent hardness of water