Advertisements
Advertisements
प्रश्न
Fill in the blank
A new substance is formed in a _______ change.
Advertisements
उत्तर
A new substance is formed in a chemical change.
APPEARS IN
संबंधित प्रश्न
The chemical name of baking soda is ______.
How do the following help in bringing about a chemical change?
catalyst .
What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.
Give reason.
Acidic soil is treated with quick lime.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Which one of the following alters the rate of the chemical reaction without itself undergoing any change?
- temperature and Pressure
- concentration of reactants
- presence of catalyst
- none of these
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
Rusting of iron is a ______ chemical change.
Multiple choice:
A reaction of a type: AB + CD → AD + CD, involves
State the original colour of the following substance and colour of residue obtained after heating.
Copper carbonate
State the original colour of the following substance and colour of residue obtained after heating.
Zinc carbonate
Distinguish by dilute sulphuric acid.
Sodium Sulphite and sodium carbonate?
Give reason for the following:
A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Addition of dilute hydrochloric acid to silver nitrate.
State the following reaction represent oxidation or reduction.
\[\ce{Al->Al+++}\]
______ gas causes tears in our eyes while cutting onions.
Which of the following statement is incorrect for a chemical reaction?
Rusting of iron is ______.
Write the chemical reaction of baking soda with lemon.
Explain how the painting of an iron gate prevents it from rusting.
Give an example where heat, light, and sound are produced during a chemical change.
______ is a chemical substance is used in whitewashing.
