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प्रश्न
Define: Chemical combination reaction
उत्तर
When two or more substances combine (a mixture of compounds) to form a single product, then the reaction is called a combination reaction.
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संबंधित प्रश्न
Write the balanced chemical equation for the following and identify the type of reaction.
\[\ce{Hydrogen(g) + Chlorine(g) -> Hydrogen chloride (g)}\]
Why is respiration considered an exothermic reaction? Explain.
Find the odd man out:
Camphor, Ammonium Chloride, Naphthalene balls, Sugar
What happens chemically when quicklime is added to water filled in a bucket?
What type of reaction is represented by the following equation?
CaO + H2O → Ca(OH)
What type of chemical reaction take place when a magnesium wire is burnt in air?
What type of chemical reaction take place when ammonia and hydrogen chloride are mixed?
What type of reaction is represented by the following equation?
CaO + CO2 → CaCO3
Define a combination reaction.
Give one example of a combination reaction which is also exothermic.
Consider the following equation of the chemical reaction of a metal M:
4M + 3O2 → 2M2O3
This equation represents:
(a) combination reaction as well as reduction reaction
(b) decomposition reaction as well as oxidation reaction
(c) oxidation reaction as well as displacement reaction
(d) combination reaction as well as oxidation reaction
What happens during a chemical reaction ?
What do you understand by a chemical bond ?
Give one example each of which illustrates the following characteristics of a chemical reaction:
change of colour
Fill in the blank
A reaction in which two or more substances combine to form a single substance is called a ............ reaction.
Fill in the blank
The chemical reaction between hydrogen and chlorine is a ................ reaction
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{CaCO3_{(s)} ->[heat]CaO_{(s)} + CO2_{(g)}}\]
A student prepared an aqueous solution of CuSO4 in beaker X and an aqueous solution of FeSO4 in beaker Y. He then dropped some iron pieces in beaker X and some zinc pieces in beaker Y. After about 10 hours he observed that the solutions in X and Y respectively appear:
(A) blue and green
(B) colourless and pale green
(C) colourless and light blue
(D) greenish and colourless
(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.
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
State why a direct combination reaction is called a – ‘synthesis reaction’.
Classify the following reaction into –
- Direct combination
- Decomposition
- Displacement
- Double decomposition
The reaction is – Molten zinc at high temperatures, burns in air to give zinc oxide.
Complete the statement by filling in the blank with the correct word:
Direct combination reaction of phosphorus pentoxide with water gives _______.
Give a balanced equation for the following type of reaction:
A reaction of direct combination i.e. synthesis in which twp gases combine to give another gas – which turns lime water milky.
The number of products formed in a synthesis reaction is ______
Define a combination reaction. Give one example of an exothermic combination reaction.
Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
Which of the following is not a physical change?
In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?
The Salt Story
From: The New Indian Express 9 March 2021
The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.
One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.
The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.
| COMPOUND | FORMULA | MASS OF SOLID PRESENT /g |
| Sodium Chloride | NaCl | 28.0 |
| Magnesium Chloride | MgCl2 | 8.0 |
| Magnesium Sulphate | MgSO4 | 6.0 |
| Calcium Sulphate | CaSO4 | 2.0 |
| Calcium Carbonate | CaCO3 | 1.0 |
| TOTAL AMOUNT OF SALT OBTAINED | 45.0 | |
Which compound in the table reacts with acids to release carbon dioxide?
Balance the following chemical equation and identify the type of chemical reaction.
`"Na"("s") + "S"("s") overset("(Fuse)")(->) "Na"_2"S"("s")`
Balance the following chemical equation and identify the type of chemical reaction.
`"CaO"("s") + "SiO"_2("s") -> "CaSio"_3("s")`
A metal ribbon 'X' bums in oxygen with a dazzling white flame forming a white ash 'Y'. The correct description of X, Y and the type of reaction is:
- Assertion: Rusting of Iron is endothermic in nature.
- Reason: As the reaction is slow, the release of heat is barely evident.
