Advertisements
Advertisements
प्रश्न
Write true or false :
When potassium iodide solution is added to lead acetate solution a red precipitate is formed.
विकल्प
True
False
उत्तर
False
APPEARS IN
संबंधित प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.
Complete and balance the following chemical equations
Na + H2 O →
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
FILL IN THE BLANK
In a double decomposition precipitation reaction both the reactants must be ............ soluble.
FILL IN THE BLANK
The new substances formed during a chemical reaction are called the ..................
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 |
Write true or false :
Hydrogen sulphide has rotten egg smell .
Balancing a chemical equation is based on
State what you would observe when the following substance is heated in a glass test tube red lead.
Name the type of chemical reaction shown by the following equation:
2Mg + O2 → 2MgO
What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.
State the conditions necessary for a chemical change or reaction.
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Multiple choice:
Thermal decomposition of sodium carbonate will produce
Define:
Photochemical reaction
Give one example
Name: A greenish-yellow gas.
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 |
State the original colour of the following substance and colour of residue obtained after heating.
Lead nitrate
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium chloride
Give reason for the following:
Even though rusting is an exothermic reaction, the heat evolved when an iron nail rusts is unnoticeable.
Give reason for the following:
The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌}
between the reactants and products, formed in the chemical reaction.
Give balanced equation for the following conversion affected by heat alone on the substance:
Ammonium dichromate to nitrogen
Complete the table given below.
| Heat on ammonium dichromate | Name of neutral gas evolved |
State the following reaction represent oxidation or reduction.
\[\ce{Al->Al+++}\]
NPK are the primary nutrients for plants.
Discuss how acid rain occurs due to emission of smoke from vehicles and industries?
______ is the chemical name of slaked lime.
