Advertisements
Advertisements
Question
Fill in the blank
A new substance is formed in a _______ change.
Solution
A new substance is formed in a chemical change.
APPEARS IN
RELATED QUESTIONS
The chemical name of baking soda is ______.
Give reason.
Wasp sting is treated with vinegar.
MATCH THE COLUMNS
| 1 . `H_2` + `CI_2` `→` 2HCI | a. displacement reaction |
| 2. `2FeCI_3`+ `H_2` `→` `2FeCI_2` +2HCI` | b. addition of an electronegative redical |
| 3. Fe + `CuSO_4` `→``FeSO_4` +Cu` | c. removal of an electronegative redical |
| 4. `2H_2O` +`4NO_2`+`O_2` `→` `4HNO_3` | d.reduction by adding hydrogen |
| 5. 3Fe +`3CI_2` `→` `2FeCI_3` | e.electrolysis of water |
| 6. `FeCI_3`+ 3NaOH `→``Fe(OH)_3``↓`+NaCI | F.double decomposition,precipitation reaction |
| 7.`2H_2O` `→` `2H_2``↑`+`O_2` | e. combination or synthesis reaction |
TRUE \ FALSE
A precipitation reaction takes place only in a solution.
TRUE \ FALSE
The evolution of a gas during a chemical reaction is shown by an arrow pointing downwards. True or false ?
Explain the type of reactions on the basis of the direction of reaction.
Fill in the blank.
Melting of ice is a _______ change.
| Reactants | Products | Type of chemical reaction |
| BaCl2(aq) + ZnSO4(aq) | H2CO3(aq) | Displacement |
| 2AgCl(s) | FeSO4(aq) + Cu(s) | Combination |
| CuSO4(aq) + Fe(s) | BaSO4↓ + ZnCl2(aq) | Decomposition |
| H2O(l) + CO2(g) | 2Ag(s) + Cl2(g) | Double displacement |
When electric current is passed through acidulated water ______ of water takes place.
Explain the term reactant and product giving examples.
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
Name: Two carbonates do not produce carbon dioxide on heating.
Distinguish by heating the following in dry test tubs.
Zinc nitrate and copper nitrate.
Distinguish by heating the following in dry test tubs.
Copper Sulphate and copper carbonate
Write your observation and a balanced equation in the case of the following substances being heated.
Copper carbonate.
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc carbonate to zinc oxide
Give a balanced equation for the conversion of a soluble lead salt to an insoluble lead salt – formed as a white precipitate.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Copper nitrate.
______ gas causes tears in our eyes while cutting onions.
Higher order Thinking question
Peeled and unpeeled banana does not look the same. Does that mean peeling banana is a chemical change?
Higher order Thinking question
A very hot glass on putting in cold water cracks. What does this change indicate?
Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.
Two chemical species X and Y combine together to form a product P which contains both X and Y
\[\ce{X + Y -> P}\]
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition
Which of the following is/are true when milk changes into curd?
- Its state is changed from liquid to semi-solid.
- It changes colour.
- It changes the taste.
- The change cannot be reversed.
Choose the correct option from below:
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
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Do you think the formation of rust from iron is a chemical change?
When magnesium is burnt in the air, a new substance is formed which is ______.
Write a note on the catalyst.
Write the effects of chemical reactions.
