Rajasthan Board Class 10 Science Chapter 5 Solution Chemistry in Everyday Life RBSE Class 10 Science Solution for Chapter 5
Objective type questions.
(1.) Aqueous solution of base
a) Turns blue litmus into red
b) Turns red litmus into blue
c) Turns litmus solution into colourless
d) Does not have any effect on litmus solution.
Ans-b) turns red litmus into blue
(2.) Solutions of acid and base are, ____ of electricity.
a) Insulator
b) Conductor
c) Semiconductor
d) No effect
Ans-b) conductor
(3.) pH is negative logarithm of which ions?
a) [H2O]
b) [OH-]
c) [H+]
d) [Na+]
Ans- c) [H+]
(4.) Which one is the pH of acidic solutions.
a) 7
b) 14
c) 11
d) 4
Ans-d) 4
(5.) In our stomach digestion of occurs in which medium.
a) Acidic
b) Alkaline
c) Neutral
d) Variable
Ans-a) acidic
(6.) In making fire extinguisher, which substance is used-
a) Sodium carbonate
b) Sodium hydrogen carbonate
c) Plaster of paris
d) Sodium chloride
Ans-b) sodium hydrogen carbonate
(7.) Washing soda is-
a) NaHCO3
b) NaCl
c) CaCO4. ½ H2O
d) Na2CO3.10H2O
Ans- d) Na2CO3.10H2O
(8.) Which gas is released on keeping bleaching powder open in air-
a) H2
b) O2
c) Cl2
d) CO2
Ans-c) Cl2
(9.) Soap works
a) In soft water
b) In hard water
c) In both soft and hard water
d) None of these
Ans-a) in soft water
(10.) In micelle formulation, hydrocarbon tail is
a) Inward
b) Outward
c) Variable
d) Towards any side.
Ans-a) Inward
(11.) Compounds formation which accept proton [H]+
a) Acid
b) Salt
c) None of these
d) Base
Ans-d) base
Very short type questions.
(12.) Which acid is found in sting of red ant?
Ans- formic acid
(13.) What are proton donor compounds called?
Ans -amphoteric compounds.
(14.) What is neutralization?
Ans- the reaction in which acid and base reacts with each other quantitavely is called neutralization.
(15.) How drinking water is made bacteria free?
Ans- boiling the water and make it bacteria free.
(16.) How acid reacts with metallic oxide? Give equation.
Ans-acid reacts with metallic oxide and forms salt and water
Metal oxide+ acid = salt + water.
CuO + 2HCL = CuCl2 + H2O
(17.) In pH, what P and H indicates?
Ans- P known as protenz and H known as hydrogen ions.
(19.) Which treatment would we take to get relief from excess acidity produced in stomach?
Ans- neutralization treatment.
(20.) Name two sodium salts.
Ans- sodium chloride, sodium carbonate.
(21.) What is saponification?
Ans-sodium and potassium salts of fatty acids with long chain of carbon like stearic acid, palmatic aicds etc these are made by heating oil or fats with sodium hydroxide or potassium hydroxide this reaction is called saponification.
(22.) Give definition of base according to lewis.
And-base are the substances that donates electron pair.
(23.) What is characteristics of detergents?
Ans- detergent are work in both soft and hard water.
(24.) Which compound is used for plastering cracked bones?
Ans- plaster of paris (CaSO4.1/2 H2O)
Short type questions.
(25.) Write name and used of two strong acids and two strong bases.
Ans-nitric acid – used in making fertilizers
Hydrochloric acid- used in industries
Calcium hydroxide –used as to remove acidity of soil
Calcium carbonate – used in making floor as marble.
(26) Differentiates soap and detergents?
Ans-
| Soap | Detergents |
| Sops are the sodium and potassium salts of fatty acids. | They are the sodium alkyl sulphate and sodium alkyl benzene sulphonate. |
| They are work in only soft water | They are work in both soft and hard water. |
| They can not perform cleaning action | They mainly used for cleaning actions. |
(27.) Write definations of acid and base according to Arrhenius.
Ans-the substance which give hydrogen iion (H+) when decomposes in water are called acids and those substances that decomposes in water and give hydroxyl ion(OH) are called bases.
(28.) What is pH? Describe pH range of acidic and alkaline solution.
Ans- pH is the negative logarithm of concentration of hydrogen ions is called pH. The range of acid is 0-7 and base is 7-14.
(29.) What is water of crystallization ? give example
Ans-the water that found in the crystalline framework is called crystallization of water.
(30.) What happens when
1) Curd or sour substances are kept in metal utensils.
Ans-curd or sour substances contains acids. And acids react with metals to produce salt and hydrogen gas.
2) Teeth are not cleaned after eating food at night.
Ans-the bad odor form in mouth.enamel cause damage and results decay and cavities.
(31.) compound A reacts with acid H2SO4 and release gas B with brisk effervescence. On heating gas B burns with pop sound. Tell names of A and B and give equation of reaction.
Ans-
Essay type question.
(32.) Explain acid and base according to bronsted Lowry and Lewis.
Ans-according to A) bronsted lowry- acids are the proton donors and base are the proton acceptors
Eg- H2O + NH3 – NH4 + OH
Here water is the proton donor so it is called acid and ammonia is proton acceptor.
B) lewis_- according acids are the substances which accept electron pair and base substances that donates electron pair.
Eg-BF3 +NH3 – F3B +NH3
Here base gives electron and lewis acid accept electron to form compound where both are attached by co-ordinate bond.
(33.) Write uses of pH in normal life.
Ans- a) Acidity in stomach- In this problems’ stomach faces pain and irritation In this gastric juice having more amount of hydrochloric acid is formed in our stomach which causes pain and burning sense. To get rid of it, antacid which means weak bases like [ Mg(OH)2] milk of magnesia are used. It neutralizes excess amount of acid in our stomach.
b) Tooth decay – Generally pH of mouth is almost 6.5 Bacteria present in the mouth reduce pH of mouth when they react with food remains in teeth by producing acid. Tooth enamel decay when pH value becomes lower than 5.5 so after eating food teeth should be cleaned by tooth paste or alkaline solution so that tooth decay can be controlled.
c) pH of soil – By determining the pH of soil, the crops that can be sown in soil can be selected and use of proper fertilizer can also be determined so that good crop is obtained.
(34) Write name, method of preparation and uses of-
Ans-
| Formula | name | Method of preparation | uses |
| NaOH | Sodium hydroxide | It is produced by the electrolysis of sodium chloride. | It isused in metallurgy of bauxite
It is used in purification of petroleum.
|
| NaHCO3 | Sodium hydrogen carbonate(baking soda) | It is prepared by passing CO2 gas in solution of sodium carbonate. | As a baking powder in food products and as mild antiseptic. |
| Na2CO3.10 H2O | Sodium carbonate( washing soda) | It is obtained on heating baking soda. | In washing and cleaning
As detergent Laboratory reagent. |
| CaOCl2 | Calcium chloride( bleaching powder) | It is produce by passing chlorine gas in dry slaked line. | As bleach in cloth industry
As bleach in paper industry. |
(35.) How micelles are formed? Write mechanism also.
Ans- micelles are formed in aqueous solution where polar and non polar region forms core.hydrocarbon part is called hydrophobic and polar part is called hydrophilic. This hydrocarbon tail which is hydrophobic and polar end which is hydrophilic makes such structure. These parts are arranged such that hydrocarbon part is inward and negatively charged polar end is outward .it is called micelle .hydrophobic part attracts impurity and hydrophilic polar part is outward. So impurity is surrounded and micelle is formed.
