What happens when
(i) magnesium is burnt in air
(ii) quick lime is heated with silica
(iii) chlorine reacts with slaked lime
(iv) calcium nitrate is heated?
1 Answers
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Calculate the amount of carbon dioxide that could be produced when 1 mole of carbon is burnt in air.
Answer: The balanced reaction of combustion of carbon can be written as: C + O2 ----------------> CO2 1 1 1 (i) As per the balanced equation, 1 mole of carbon burns in 1 mole...
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A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?
When ethyne is burnt in air, it gives a sooty flame. This is due to incomplete combustion caused by limited supply of air. However, if ethyne is burnt with oxygen,...
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Identify and state the type of transformation of energy in the following cases: (a) When coal is burnt. (b) In a thermal power plant
(a) Chemical energy stored in coal is converted to heat energy. (b) Chemical energy of fuel is first converted into heat energy than to kinetic energy and finally to electrical energy.
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Calculate the number of moles of magnesium present in a magnesium ribbon weighing 12 g. Molar atomic mass of magnesium is 24g mol–1.
Number of moles 12 / 24 = 0.5 mol
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Compute the difference in masses of 10^3 moles each of magnesium atoms and magnesium ions. (Mass of an electron = 9.1×10–31 kg)
A Mg2+ ion and Mg atom differ by two electrons. 103 moles of Mg2+ and Mg atoms would differ by 103 × 2 moles of electrons Mass of 2 ×103 moles of electrons...
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Why should a magnesium ribbon be cleaned before burning in air.
When magnesium ribbon is exposed to air, it reacts with oxygen in the air to form magnesium oxide. This oxide layer interferes with the burning of magnesium ribbon. Thus, the...
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What is redox reaction? When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
i. The reaction in which one reactant gets oxidised and the other reactant gets reduced is called redox reaction. ii. When a magnesium ribbon burns in air with a dazzling flame...
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i. What do you see when a magnesium ribbon is burnt? Is magnesium oxidised or reduced in this reaction? ii. Define corrosion.
When magnesium ribbon is burnt, dazzling white flame is observed and there is formation of white ash. Magnesium is said to be oxidised as it is combining with oxygen. ii. The...
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A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used.
i. Ethyne is an unsaturated hydrocarbon. On combustion in air, it produces a yellow flame with lots of black smoke. ii. Due to this incomplete combustion, heat produced is low and...
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A magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light.
(i) 2Mg + O2→ 2MgO + Light 3Mg + N2→ Mg3N2 (a) X is MgO; Y is Mg3N2 (b) MgO + H2O→ Mg(OH)2 (ii) Grapes when attached to the plants are living and therefore,...
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