science important notes on ch 1 class10
Answers
1. law of conservation of mass.
2. definations with examples
3.to balance reactions.
4. corrosion, rancidity
Answer:
Chemical Reactions
Such a process in which breaking and making of bonds between different atoms to produces substances of new property is known as chemical reaction. We should have to determine the chemical reaction has taken place, if there is:
Change in state.
Change in colour.
Evolution of a gas.
Change in temperature.
What Is A Chemical Equation?
The representation of chemical reaction in the form of formulae of reactants and products separated by an arrow marks is known as a Chemical Equation.
What Are Different Type Of Chemical Reactions?
The types of reaction are as follow;
(1) Combination reaction
(2) Decomposition reaction
(3) Displacement reaction
(4) Double displacement reaction
(5) Oxidation and reduction reaction
What Is Decomposition Reaction?
The reaction in which a single reactant breaks down into two or more than two simpler products is known as decomposition reaction.
General form of Decomposition Reaction is given by:
A → B + C
What Are Exothermic Reactions?
Reactions in which heat is released along with the formation of products are calle
d exothermic.
During the reaction large amount of heat (energy) is evolved and this heat makes the reaction mixture warm.
Respiration Is An Exother
mic Reaction
When we take food to get energy to stay alive. During digestion, food is broken down into simpler substances likes carbohydrates and other nutrients. These carbohydrates further broken down to form glucose. This glucose combines with oxygen in cells of our body in the process of cellular respiration and provide energy. Therefore, respiration is also an exothermic reaction.
Corrosion
The process in which metals looses their surface gradually by the action of air, water and moisture is called corrosion.
In other words:
The process in which metals surface get corroded by reaction with air, water and moisture is called corrosion.
Corrosion is not a rusting while rusting causes corrosion.
Preventing Corrosion
There are following method to prevent corrosion:
(i) By galvanization
(ii) By painting metal surfaces
(iii) By oiling or greasing metal surfaces