Solve the following problems using appropriate strategy or tools.
1. Rayver can build 4 4/5of his robot toy collection for 1 hour, How many
robots can he build in 1 2/3 hr?
2. A long jump competition was held at Barangay Mathalino. John Mark
jumped 2/3 of 6 3/5meters of the field. How far did John Mark jump?
Answers
Step-by-step explanation:
Question :
Define with examples
a) Decomposition reaction
b) Double Displacement reaction
c) Redox reaction
ANSWER
Decomposition reaction : -
A reaction in which a single compound divides/splits into 2 or more compounds when some external energy is supplied is called Decomposition reaction.
Represented as;
AB -----> A + B
Depending upon the externally energy supplied the reactions are of 3 types;
Thermal Decomposition reaction
Electrolytic Decomposition reaction
Photo/Photo chemical Decomposition reaction
A reaction in which heat is evolved is generally termed as Exothermic reaction.
( Here, exo means releasing out)
Similarly,
A reaction in which heat is absorbed is generally
termed as Endothermic reaction.
( Here, endo means absorption)
Examples for Decomposition reaction;
1.
\sf{ CaCO_3 \xrightarrow{heat \Delta} \quad CaO + CO_2}CaCO
3
heatΔ
CaO+CO
2
2.
\sf{ 2H_20 \xrightarrow{electricity} \quad 2H_2 + O_2 }2H
2
0
electricity
2H
2
+O
2
3.
\sf{ 2AgBr \xrightarrow{sunlight} \quad 2Ag + Br_2 }2AgBr
sunlight
2Ag+Br
2
Double Displacement reaction : -
A reaction in which there is an exchange of ions between 2 radicals is called as Double Displacement reaction. In a double displacement reaction 2 new compounds will be formed.
Represented as;
AB + CD ----> AC + BD
These are of 2 types;
Precipitation reaction
Neutralising reaction
Examples;
1.
\sf{NaSO_4 + BaCl arrow BaSO_4 + NaCl}NaSO
4
+BaClarrowBaSO
4
+NaCl
2.
\sf{ AgNO_3 + NaCl arrow AgCl + BaNO_3}AgNO
3
+NaClarrowAgCl+BaNO
3
Redox reaction : -
A redox reaction is a chemical reaction in which in there is an exchange of electrons among the reactants.
Generally, in this reaction the oxygen is removed when we add hydrogen to the compound.
However,
The word redox means reduction-oxidation.
Reduction : Gain of electrons or Add of hydrogen
Oxidation : Loss of electrons or add of oxygen
Examples;
1.
\sf{ H_2 + F_2 arrow 2HF }H
2
+F
2
arrow2HF
2.
\sf{ MgO +H_2 arrow Mg + H_2O }MgO+H
2
arrowMg+H
2
O