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प्रश्न
(a) What is double displacement reaction? Explain with an example.
(b) A small amount of quick lime is added to water in a beaker.
(i) Name and define the type of reaction that has taken place.
(ii) Write balanced chemical equation for the above reaction and the chemical name of the product formed.
(iii) List two main observations of this reaction.
उत्तर
(a) Double Displacement Reaction : Reactions in which there is an exchange of ions between the reactants are called Double Displacement Reactions.
Example : \[\ce{Pb(NO3)2_{(aq)} + 2KI_{(aq)} -> \underset {\text{(Yellow ppt)}}{PbI_2}( v) + 2KNO3_{(aq)} }\]
(b) (i) Reaction taking place is combination reaction. A reaction in which two or more reactants combine to form a single product is known as combination reaction.
\[\ce{\underset{\text{Quick lime}}{CaO_{(s)}} + H2O_{(l)} -> \underset{\text{(Calcium hydroxide)}}{Ca(OH)2_{(aq)}} + Heat}\]
(iii) Two main observations :Calcium oxide when reacts vigorously with water produces slaked lime i.e Ca(OH)2 . A large amount of heat is evolved . This is an Exothermic reaction .
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संबंधित प्रश्न
A silvery-white metal X taken in the form of ribbon, when ignited, burns in air with a dazzling white flame to form a white powder Y. When water is added to powder Y, it dissolves partially to form another substance Z.
(a) What could metal X be?
(b) What is powder Y?
(c) With which substance metal X combines to form powder Y?
(d) What is substance Z? Name one domestic use of substance Z.
(e) Write a balanced chemical equation of the reaction which takes place when metal X burns in air to form powder Y.
What type of reaction is represented by the following equation?
CaO + H2O → Ca(OH)
Define a combination reaction.
Give one example of a combination reaction which is also endothermic.
What are chemical combination or synthesis reactions ? Chemical combination or synthesis:
Calcium oxide reacts vigorously with water to produce slaked lime.
\[\ce{CaO{(s)} + H2O(l) -> Ca(OH)2(aq)}\]
This reaction can be classified as:
(A) Combination reaction
(B) Exothermic reaction
(C) Endothermic reaction
(D) Oxidation reaction
Explain the following reaction with their balanced chemical equation.
Ammonia gas reacts with hydrogen chloride.
Identify the correct option from the given table which represents the type of reactions occurring in step 1 and step 2.
Balance the following chemical equation and identify the type of chemical reaction.
`"Mg"("s") + "Cl"_2("g") -> "MgCl"_2("s")`
Read the text below and answer the questions that follow:
A small amount of hydrochloric acid was taken in a test tube. The test tube was heated. A glass rod was dipped in the ammonia solution and held on the top of the test tube. A white smoke was seen emanating from the tip of the glass rod.
- What must have happened?
- Which colour of gas is formed?
- Write the chemical equation for the reaction.
