Case study
A chemical reaction is a representation of chemical change in terms of symbols and formulae of reactants and products. There are various types of chemical reactions like combination,decomposition, displacement, double displacement, oxidation
and reduction reactions. Reactions in which heat is released along with the formation of products are called exothermic chemical reactions. All combustion reactions are exothermic
reactions.
The chemical reaction in which a single substance breaks
down into two or more simpler substances upon heating is
known as
(a) thermal decomposition reaction
(b) photo decomposition reaction
(c) electric decomposition reaction
(d) both (a) and (c)
The massive force that pushes the rocket forward through
space is generated due to the
(a) combination reaction
(b) decomposition reaction
(c) displacement reaction
(d) double displacement reaction
A white salt on heating decomposes to give brown fumes and yellow residue is left behind. The yellow residue left is of
(a) lead nitrate
(b) nitrogen oxide
(c) lead oxide
(d) oxygen gas
Which of the following reactions represents a combination reaction?
(a) CaO (s) + H2O (l) → Ca(OH)2 (aq)
(b) CaCO3 (s) → CaO (s) + CO2(g)
(c) Zn(s) + CuSO4 (aq) → ZnSO4 (aq) + Cu(s)
(d) 2FeSO4(s) → Fe2O3 (s) +SO2(g) + SO3(g)
Complete the following statements by choosing correct type
of reaction for X and Y.
Statement 1: The heating of lead nitrate is an example of ‘X’
reaction.
Statement 2: The burning of magnesium is an example of ‘Y’
reaction.
(a) X- Combination, Y- Decomposition
(b) X- Decomposition, Y-Combination
(c) X- Combination, Y-Displacement
(d) X- Displacement, Y-Decomposition
Answers
Answer:
sorry I don't know this answer
The correct option to the above questions are as follow -
1. Thermal decomposition reaction - The decomposition reaction are the reaction in which a compound or reactant decomposed into two or more than two products.
- In a thermal reaction, energy in the form of heat energy is required to break the compound's bond.
- So the correct option is (a).
2. Decomposition reaction - The decomposition reaction produces energy that is required to produce a force that pushes the rocket through space.
- Hydrogen peroxide is used in a space rocket, that decomposes to produce a forceful thrust.
- So, the correct option is (b).
3. Lead oxide - The white salt is lead nitrate. On heating, it decomposes into lead oxide and nitrogen oxide.
- Nitrogen oxide is brown fumes, and the yellow residue is lead oxide.
- So, the correct option is (c).
4. CaO (s) + H₂O (l) → Ca(OH)₂ (aq) - A combination reaction is a reaction in which two or more reactants are combined to form a single product.
- It is also known as a synthetic reaction.
- All the equation apart from this is either decomposition reaction, substitution reaction, or displacement reaction.
- So, the correct option is (a)
5. X- Decomposition, Y-Combination - Lead nitrate upon heating produces lead oxide, nitrogen oxide.
- Magnesium reacts with oxygen upon burning to form magnesium oxide. Hence it is a combination reaction.
- So, the correct option is (b).