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प्रश्न
Name three biochemical catalysts found in the human body.
उत्तर
Biochemical catalysts found in human body:
- Pepsin
- Tryspin
- lipase.
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संबंधित प्रश्न
Complete and balance the following chemical equations:
Fe `"SO"_4` + NaOH `→`
(aq.) (aq.)
FILL IN THE BLANK
On reaction with sulphuric acid solution, barium chloride forms a white precipitate of ........ sulphate.
TRUE \ FALSE
Evaporation of water is a physical change. True or false ?
Fill in the blank
A new substance is always formed in a _______ change.
Fill in the blank
A new substance is formed in a _______ change.
State four conditions necessary for chemical reactions to take place.
Fill in the blank:
The substances which undergo chemical change are called _______
Give an example of a reaction where the following are involved
Pressure
Give an example of the following chemical change.
Two solids combine to form a liquid
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Multiple choice:
Which of the following is not a characteristic of a chemical change?
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State the original colour of the following substance and colour of residue obtained after heating.
Lead nitrate
What do you observe when H2S is passed through a lead nitrate solution.
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium chloride
State the following reaction represent oxidation or reduction.
\[\ce{Cu++->Cu}\]
Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to calcium carbonate.
Select the correct answer from the options given below:
State the gaseous product formed, when
An active metal reacts with dilute sulphuric acid.
Burning of paper is a ______ change.
________ is a chemical substance which alters the speed of a chemical reaction.
Silver metal can displace hydrogen gas from nitric acid.
Silver articles turning black: ______:: Boiling of H2O: physical change ______.
Burning of paper is the best example of ______ change.
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.
Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood
State whether the following statements are true or false:
When a candle burns, both physical and chemical changes take place.
Is the conversion of milk into ice cream a chemical change?
Give an example where heat, light, and sound are produced during a chemical change.
Acid rain is a result of ______.
