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प्रश्न
Write true or false :
No new substance is formed during a chemical reaction.
पर्याय
True
False
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उत्तर
False
APPEARS IN
संबंधित प्रश्न
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.
Complete and balance the following chemical equations
NaCI + `AgNO_3` `→`
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
Define chemical reaction.
Fill in the blank:
The substances which undergo chemical change are called _______
Match the column in the following table.
| 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 |
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)
Electron ______ is complete in each hydrogen in a hydrogen molecule.
Explain by writing a word equation.
Limestone powder disappears on adding to dilute hydrochloric acids.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Potassium fluoride
Give an example of a reaction where the following are involved
Heat
What do you understand by 'chemical 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.
Select the correct answer for the following options:
The pale blue precipitated obtained when copper [II] sulphate reacts with sodium hydroxide.
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc nitrate to nitrogen dioxide
Discuss how acid rain occurs due to emission of smoke from vehicles and industries?
Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood
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
Classify the following as physical or chemical properties
Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.
Rusting of iron is ______.
Give an example where heat, light, and sound are produced during a chemical change.
