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प्रश्न
Define chemical reaction.
उत्तर
Chemical reaction : Any chemical change in matter which involves its transformation into one or more new substances is called a chemical reaction.
संबंधित प्रश्न
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Which one of the following alters the rate of the chemical reaction without itself undergoing any change?
- temperature and Pressure
- concentration of reactants
- presence of catalyst
- none of these
TRUE \ FALSE
Weak electrolytes dissociate partially in their aqueous or fused state.
TRUE \ FALSE
Positively charged electrode is called the anode. True or false ?
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
To prevent rusting, a layer of ______ metal is applied on iron sheets.
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)
Oxygen is a ______ in respiration.
Explain by writing a word equation.
Limestone powder disappears on adding to dilute hydrochloric acids.
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.
When electric current is passed through acidulated water ______ of water takes place.
Give an example of a reaction where the following are involved:
Solution
State the type of reactions for the following represent and balance the ones that are not balanced.
NaOH + HCl → NaCl + H2O
Multiple choice:
Which of the following is not a characteristic of a chemical change?
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Define:
Electrochemical reaction
Give one example
Name: Two nitrates that do not produce nitrogen dioxide on heating.
Write your observation and a balanced equation in the case of the following substances being heated.
Zinc carbonate.
Select the correct answer for the following options:
The black residue obtained on heating copper carbonate.
Give a word equation for the following reaction.
An exothermic reaction where both the reactants are gases, one of which is oxygen.
What is a chemical reaction?
Complete the table given below.
| Heat on copper carbonate | Test for gas evolved |
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 |
State the following reaction represent oxidation or reduction.
\[\ce{H->H+}\]
Give a suitable example with an equation to show the representation of a chemical reaction.
True or False. If false, give the correct answer.
Taking a glass of water and freezing it by placing it in the freezer is a chemical change.
Higher order Thinking question
A very hot glass on putting in cold water cracks. What does this change indicate?
Silver articles turning black: ______:: Boiling of H2O: physical change ______.
Rusting of iron is ______.
______ occurs in the absence of air and in the presence of micro-organisms such as yeast.
Write the chemical reaction of baking soda with lemon.
What is thermochemical reactions?
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.
