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प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
उत्तर
The reaction between hydrogen sulphide and chlorine (both gases) produces sulphur (solid) and hydrogen chloride (gas).
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संबंधित प्रश्न
When carbon dioxide is passed through lime water, it turns milky due to the formation of ______.
How do the following help in bringing about a chemical change?
catalyst .
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
Write the missing reactants and products and balance the equations.
................+ HCI
What are oxides ?
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer
Which of the following is a reducing agent?
- oxygen
- chlorine
- hydrogen
- none of these
FILL IN THE BLANK
Negatively charged ions are called ..........
FILL IN THE BLANK
The new substances formed during a chemical reaction are called the ..................
Explain the type of reactions on the basis of the direction of reaction.
Fill in the blank
A change in which the substance can be brought back to its original state is called a _______ change.
Fill in the blank
A new substance is formed in a _______ change.
Balancing a chemical equation is based on
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.
Name: Two nitrates that do not produce nitrogen dioxide on heating.
What is observed in performing the following :
| Hydrogen | Oxygen | Carbon dioxide | Chlorine | |
| Litmus test | ||||
| Apply a burning splint to the gas | ||||
| Colour of gas | colourless | colourless | colourless | greenish-yellow |
| Odour of gas |
What do you observe when H2S is passed through a lead nitrate solution.
What do you observe when Cl2 is passed through potassium iodide (KI) solution.
Give a chemical test to distinguish between the following gases.
H2 and O2
Distinguish by dilute sulphuric acid.
Sodium Sulphite and sodium carbonate?
Give reason for the following:
Even though rusting is an exothermic reaction, the heat evolved when an iron nail rusts is unnoticeable.
Explain the Silver nitrate solution is kept in coloured reagent bottles in the laboratory.
When lithium metal is placed in hydrochloric acid, _______ gas is evolved.
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
What is the use of indicator?
State whether the following statements are true or false:
When a candle burns, both physical and chemical changes take place.
Melting of wax is a change where a solid changes to a liquid state. Give one more such change which you observe in your surroundings
Give an example of a chemical reaction for each of the following situations:
A change in colour is observed.
______ are substances that speed up the process of a chemical change and it will not undergo any change during the course of the reaction.
Give an example where heat, light, and sound are produced during a chemical change.
Write the effects of chemical reactions.
