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प्रश्न
Balancing a chemical equation is based on
पर्याय
Law of conservation of mass
Mass of reactants and products
Symbols and formulae
None of the above
उत्तर
Law of conservation of mass.
APPEARS IN
संबंधित प्रश्न
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer
Which of the following is a reducing agent?
- oxygen
- chlorine
- hydrogen
- none of these
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
FILL IN THE BLANK
The new substances formed during a chemical reaction are called the ..................
Define chemical reaction.
State four conditions necessary for chemical reactions to take place.
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
A chemical equation is a statement that describes a chemical change in terms of
What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Water
Give reason for the following:
Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
Explain,giving one example of the following chemical changes:
Reversible reaction
Complete the following table and write your observations.
|
Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
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|
Shake the gas with red litmus solution |
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Shake the gas with blue litmus solution |
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Apply a burning splint to a gas |
What do you observe when HCI is passed through a silver nitrate solution.
Write your observation and a balanced equation in the case of the following substances being heated.
Copper carbonate.
Represent the addition of dilute sulphuric acid to zinc by means of a chemical equation. State the function of the arrow between the reactants and products.
Give a word equation for the following reaction.
A compound which on heating shows – colour change from brown to yellow.
Complete the table given below.
| Flame test for calcium chloride | Acid used for flame test |
State the following reaction represent oxidation or reduction.
\[\ce{Al->Al+++}\]
State whether the following reaction is oxidation or reduction.
\[\ce{Na->Na+}\]
Complete the statement by filling in the blank with the correct word:
The reddish-brown precipitate obtained during a double decomposition precipitation reaction between an iron salt and alkali is __________.
What happens when cane sugar is strongly heated? Mention any two changes in it.
The chemical change is ______.
When lithium metal is placed in hydrochloric acid, _______ gas is evolved.
Chemists identify gypsum as a natural indicator.
Analogy:
H2O: Water:: NaCl: ______.
Heat may evolve or be absorbed during a ______ change.
______ are substances that speed up the process of a chemical change and it will not undergo any change during the course of the reaction.
Galvanization is a process in which ______ is coated as a layer of iron.
What are the chemical reactions that occur in everyday life?
