EASY
Earn 100

What is the process used to measure the heat released or absorbed by a chemical reaction or physical process?

50% studentsanswered this correctly

Important Questions on Chemical reactions and Equations

MEDIUM
The colour of NO2 and PbO formed when lead nitrate is heated are:
MEDIUM
The electrolysis of acidified water is an example of: 
HARD
Explain reduction in terms of gain or loss of oxygen with two examples.
MEDIUM
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
MEDIUM
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
HARD
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
MEDIUM
State the observations you would make on adding sodium hydroxide to aqueous solution of ferrous sulphate.
MEDIUM

What is your observation in the following case:

Sodium sulphate solution reacting barium chloride solution.

MEDIUM
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
HARD
A solution of a substance ‘X’ is used for whitewashing.
(i) Name the substance ‘X’ and write its formula.
(ii) Write the reaction of the substance ‘X’ named in (i) above with water
HARD
Why is respiration considered an exothermic reaction? Explain.
HARD
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved
HARD
Identify the substances that are oxidized and the substances that are reduced in the following reaction:
4Nas+O2g2Na2Os
HARD
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed.
MEDIUM
A precipitate is formed when a colourless solution of sodium sulphate is mixed with the colourless solution of barium chloride. What is the chemical name, chemical formula and colour of the precipitate? 
HARD
Explain the oxidation in terms of gain or loss of oxygen with two examples.
MEDIUM
What does one mean by exothermic and endothermic reactions? Give examples.
HARD
The sulphate of a metal A on heating gives two gases B and C and an oxide D, gas B turns K2Cr2O7 paper green while gas C forms a trimer in which there is no S-S bond. Compound D with concentrated HCl forms a Lewis acid E, which exists in a dimer. Identify compounds A, B, C, D and E, respectively.
MEDIUM

What is your observation in the following case:

Iron reacting with copper sulphate solution in water.