Advertisements
Advertisements
Questions
What do you observe when iron nail is kept in copper sulphate solution for sometime.
What happens when an iron nail is dipped in copper (II) sulphate solution? Write balanced chemical equations to support your answer.
Advertisements
Solution
When an iron nail is kept in copper sulphate solution, a reddish brown coating is seen on the iron nail after sometime. Also, the colour of the copper sulphate solution changes from blue to green. This is observed because iron displaces copper from copper sulphate solution, as iron is more reactive than copper.
\[\ce{Fe_{(s)} + CuSO4_{(aq)} -> FeSO4_{(aq)} + Cu_{(s)}}\]
RELATED QUESTIONS
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Iron and rust are the same substances.
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Condensation of steam is not a chemical change.
The gas we use in the kitchen is called liquefied petroleum gas (LPG). In the cylinder, it exists as a liquid. When it comes out from the cylinder it becomes a gas (Change − A), then it burns (Change − B). The following statements pertain to these changes. Choose the correct one.
Fill in the blank
A catalyst either ................or ............... the rate of a chemical change but itself remains ............... at the end of the reaction.
TRUE \ FALSE
Ammonia is a good oxidizing agent.
Define electrolysis.
Write a short note on the information derived from a balanced chemical equation.
How is a strong electrolyte different from a weak electrolyte?
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 spoiling of food is a chemical change which is recognized from the generation of certain ______ due to it.
Give one example electrochemical reaction.
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.
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Addition of dilute acid to an active metal.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper nitrate to nitrogen dioxide
Limestone contains ______ mainly.
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?
Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.
Which of the following is a chemical change?
Melting of wax is a change where a solid changes to liquid state. Give one more such change which you observe in your surroundings
Write word equations for two chemical reactions with the help of materials given in the box.
| Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water |
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
