| 1 |
Thermal decompositionof calcium carbonate produces a gas. |
- A. Oxygen
- B. Carbon di oxide
- C. Nitrogen
- D. Carbon monoxide
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| 2 |
During photosynthesis in plants, carbon dioxide CO2 and water react to produce. |
- A. Water
- B. Energy
- C. Glucoe
- D. CO2
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| 3 |
The equation in which the number of atoms of each element on both sides are not equal is called. |
- A. Quadratic equation
- B. Unbalanced equation
- C. Balanced equation
- D. Standard equation
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| 4 |
Fire works is an example of ........... reactions. |
- A. Addition
- B. Exothermic
- C. Endothermic
- D. Decomposition
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| 5 |
Substancs whihc take part in a chemical reaction are called. |
- A. Products
- B. Ractants
- C. Elements
- D. Compunds
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| 6 |
When methane is burnt in air, CO2 and.......... are formed. |
- A. O2
- B. H2O
- C. Glucose
- D. Energy
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| 7 |
Exothermic reaction ae those reactions durng which heat is. |
- A. Given out
- B. Remain same
- C. Absorbed
- D. Used
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| 8 |
How many oxygen atoms are present in onw molecule of Mg(HCO3)2 |
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| 9 |
Symbol and formulae of the reactants are written on....... side fo arrow. |
- A. Left
- B. Right
- C. Upward
- D. Both side
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| 10 |
Law of conservation of mass put forward in. |
- A. 1783
- B. 1784
- C. 1785
- D. 1786
|