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प्रश्न
How do the following help in bringing about a chemical change?
light.
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उत्तर
Some chemical reactions can take place in the presence of light. Ex. Photosynthesis.
\[\ce{6CO2 + 6H2O⇌[sunlight][Chlorophyll]\underset{\text{glucose}}{C6H12O6 +6O2}}\]
APPEARS IN
संबंधित प्रश्न
How do the following help in bringing about a chemical change?
pressure.
How do the following help in bringing about a chemical change?
catalyst .
Complete and balance the following chemical equations:
Fe `"SO"_4` + NaOH `→`
(aq.) (aq.)
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Compounds, which in their molten state allow an electric current to pass through them are called
- electrolytes
- non-electrolytes
- non-conductors
- none of these
Differentiate between in Chemical reaction and chemical equation.
Write true or false :
No new substance is formed during a chemical reaction.
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)
The white particles of baking soda disappear when put in lemon juice. This means that it is a ______ change.
Explain by writing a word equation.
Bubbles are seen on adding lemon juice to baking soda.
Give an example of a reaction where the following are involved:
Close contact
Select the correct answer for the following options:
The black residue obtained on heating copper carbonate.
Select the correct answer for the following options:
The pale blue precipitated obtained when copper [II] sulphate reacts with sodium hydroxide.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Lead nitrate.
What happens when cane sugar is strongly heated? Mention any two changes in it.
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?
Burning of paper is the best example of ______ change.
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Can you change rust back into iron by some simple method?
Write a note on the following:
Curdling of milk
______ is the chemical name of limestone.
Define the following term:
Chemical change
