Advertisements
Advertisements
प्रश्न
A chemical equation is a statement that describes a chemical change in terms of
विकल्प
symbols and formulae
energy
number of atoms
colours
Advertisements
उत्तर
symbols and formulae.
APPEARS IN
संबंधित प्रश्न
Complete and balance the following chemical equations:
Zn + `"H"_2"SO"_4` `→`
(dil)
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
FILL IN THE BLANK
On reaction with sulphuric acid solution, barium chloride forms a white precipitate of ........ sulphate.
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.
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
The conversion of ferrous sulphate to ferric sulphate is ______ reaction.
Explain,giving one example of the following chemical changes:
Reversible reaction
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 |
Select the correct answer for the following options:
The black residue obtained on heating copper carbonate.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A coloured substance which leaves a black residue and evolves two gases one of which is acidic and coloured and the other neutral and colourless.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper carbonate to copper oxide
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper nitrate to nitrogen dioxide
Complete the table given below.
| Heat on iodine crystals | Colour of vapours evolved |
Complete the table given below.
| Addition of dil. H2SO4 to FeS | Odour of gas evolved |
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 __________.
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide.
(a) Is this a physical or a chemical change?
(b) Can you prepare one acidic and one basic solution by using the products formed in the above process? If so, write the chemical equation involved.
Match the following:
| Column I | Column II | ||
| 1. | Burning of coal | a. | Rusting |
| 2. | Painting of a surface | b. | Evaporation |
| 3. | Dipping iron in the water | c. | Chemical change |
| 4. | Salt from seawater | d. | Prevention of rusting |
Chemical changes are important in our day-to-day life. Give examples.
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
