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प्रश्न
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
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उत्तर
In some chemical reactions an insoluble precipitate is formed when two solutions are mixed.
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संबंधित प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
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
State four conditions necessary for a chemical reaction to take place.
Explain the following reaction with one suitable example of Decomposition reaction
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
To prevent rusting, a layer of ______ metal is applied on iron sheets.
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.
Explain by writing a word equation.
Bubbles are seen on adding lemon juice to baking soda.
Define the following term:
Precipitate
Give an example of a reaction where the following are involved
Catalyst
Name: Two carbonates do not produce carbon dioxide on heating.
What do you observe when H2S is passed through a lead nitrate solution.
Select the correct answer for the following options:
The gas which reacts with oxygen to give a neutral liquid.
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 acid to an active metal.
Give balanced equation for the following conversion affected by heat alone on the substance:
Ammonium dichromate to nitrogen
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc nitrate to nitrogen dioxide
State the following reaction represent oxidation or reduction.
\[\ce{Fe++->Fe+++}\]
Explain the term chemical reaction with special reference to reactants and products.
Which of the following is not an “element + element → compound” type reaction?
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
