Advertisements
Advertisements
प्रश्न
Give reason for the following:
A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.
Advertisements
उत्तर
A characteristic change of colour is seen when piece of iron is added to Copper (II) sulphate Solution. This is because iron displaces copper from the copper sulphate solution and forming ferrous sulphate
CuSO4 + Fe → FeSO4 + Cu.
Hence, Blue colour of the solution in changes to pale green and there is a reddish brown deposits on copper.
APPEARS IN
संबंधित प्रश्न
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.
FILL IN THE BLANK
........... electrolytes dissociate completely in aqueous state and allow large amount of electricity to flow through it.
TRUE \ FALSE
The evolution of a gas during a chemical reaction is shown by an arrow pointing downwards. True or false ?
Fill in the blank.
Melting of ice is a _______ change.
Fill in the blank:
During a chemical reaction transfer of ________ takes place.
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.
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 reason for the following:
Molybdenum is used in the manufacture of ammonia.
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 white solid which evolves two colourless gases which on cooling combine and condense on the cooler parts of the test tube.
Complete the table given below.
| Heat on iodine crystals | Colour of vapours evolved |
Complete the table given below.
| Addition of dil. H2SO4 to zinc | Test for gas evolved |
Complete the table given below.
| Flame test for calcium chloride | Acid used for flame test |
Match the chemical reactions in List I with the appropriate answer in List II.
| List I | List II | ||
| 1. | \[\ce{XY⇌[heat]X + Y}\] | A: | Displacement reaction |
| 2. | \[\ce{XY->X + Y}\] | B: | Double decomposition |
| 3. | \[\ce{X+Y- + A+B^-->X+B- + A+Y-}\] | C: | Endothermic reaction |
| 4. | \[\ce{X + YZ->XZ + Y}\] | D: | Thermal dissociation |
| 5. | \[\ce{X + Y->[heat]XY -\Delta}\] | E: | Decomposition reaction |
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to calcium carbonate.
Differentiate between the following:
Neutralization reaction and a precipitation reaction.
Match the following:
| 1. | Sodium Chloride | a. | CaSO41/2H2O |
| 2. | Calcium sulphate dihydrate | b. | C2H5Oh |
| 3. | Magnesium sulphate hydrate | c. | CaSO4.2H2O |
| 4. | Calcium sulphate hemihydrate | d. | NaCl |
| 5. | Phenol | e. | MgSO4.H2O |
Classify the following as physical or chemical properties
Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.
______ are substances that speed up the process of a chemical change and it will not undergo any change during the course of the reaction.
Collect information about the types of fuels used for cooking in your area. Discuss with your teachers/parents/others which fuels are less polluting and why.
