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प्रश्न
True or false
New substances are formed in a chemical change.
पर्याय
True
False
उत्तर
True
APPEARS IN
संबंधित प्रश्न
Changes in which new substances are formed are called ______ changes.
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
Write the missing reactants and products and balance the equations.
................+ HCI `→` NaCI + `"H"_2"O"` + .........................
What are oxides ?
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
Define electrolysis.
Fill in the blank.
Melting of ice is a _______ change.
Fill in the blank:
The substances formed as a result of a chemical reaction are called _______
Write true or false :
No new substance is formed during a chemical reaction.
Name the type of chemical reaction shown by the following equation:
Fe + CuSO4 → FeSO4 + Cu
Name the type of chemical reaction shown by the following equation :
Fe2O3 + 2Al → Al2O3 + 2Fe
A solution of a substance ‘X’ is used for white washing write the reaction of the substance ‘X’ named in (a) above with water.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Hydrogen chloride
Give reason for the following:
Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
Complete and balance the following reaction:
\[\ce{CuCO3 ->[\Delta]}\]
State the original colour of the following substance and colour of residue obtained after heating.
Lead nitrate
Give a chemical test to distinguish between the following gases.
HCl and Cl2
Distinguish by heating the following in dry test tubs.
Zinc carbonate, Copper carbonate and lead carbonate.
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium chloride
Distinguish by dilute sulphuric acid.
Copper and magnesium?
Explain the term ‘chemical reaction’ with special reference to – ‘reactants’ and ‘products’.
Explain the Silver nitrate solution is kept in coloured reagent bottles in the laboratory.
Differentiate between the following:
Neutralization reaction and a precipitation reaction.
NPK are the primary nutrients for plants.
Analogy:
H2O: Water:: NaCl: ______.
Arrange the following statements in correct sequence:
- One side is water-loving and other water-hating molecules.
- When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
- The dirt surrounded by the detergent molecules floats in the water making it dirty.
- Finally, the cloth is clean.
- The detergent molecules have two sides.
- Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.
State whether the following statements are true or false:
When a candle burns, both physical and chemical changes take place.
Iron benches kept in lawns and gardens get____________. It is a _________ change because a new _________ is formed.
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
Write a word equation for the chemical change, if any.
Write a note on the following:
Curdling of milk
