Q18 of 44 Page 1

Which of the following are combination reactions?




A combination reaction is one in which or more reactants combine to form a single product. In reaction (ii), MgO and H2O combine to from Mg (OH)2. In reaction (iii), Al and O2 combine to form Al2O3. A combination reaction is also known as synthesis reaction.


Reaction (i) is decomposition reaction and reaction (iv) is displacement reaction.

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16

Which one of the following processes involve chemical reactions?

 17

In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

 19

Write the balanced chemical equations for the following reactions and identify the type of reaction in each case.

(a) Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773 K to form ammonia gas.


(b) Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water.


(c) Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated H2SO4.


(d) Ethane is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.


Chemical Reactions and Equations

 20

Write the balanced chemical equation for the following reactions and identify the type of reaction in each case.

(a) In Thermite reaction, iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide.


(b) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride


(c) Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine.


(d) Ethanol is burnt in air to form carbon dioxide, water and releases heat.