Combination and Decomposition Reaction

A decomposition reaction can be recognized because it has...

• only one product

• only one reactant

• 2 or more reactants and 2 or more products

• the presence of a catalyst

A chemical change in which two substances react to form a new substance is a ____________________________.

• decomposition reaction

• Combination reaction

• precipitation reaction

• combustion reaction

Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:

• Make the ribbon surface shinier

• Remove the layer of magnesium oxide from the ribbon surface

• Remove the layer of magnesium carbonate from the ribbon surface

• Remove the moisture from the ribbon surface

When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:

• Blue to green

• Green to blue

• Green to brown

• Green to yellow

A decomposition reaction occurring with help of heat energy is______________

Initial colour of ferrous sulphate crystals is_________

Ferrous Sulphate is a ______ salt with formula____________

On being heated the colour of Ferros sulphate changes to _________ initially.

On sustained heating the colour of Ferrous sulphate crystals changes to__________

The gases liberated when ferrous sulphate is heated strongly have a ____________ odour.