Distinguish Between Acids And Bases

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Form ten Science Chapter 2 Extra Questions and Answers Acids Bases and Salts

Extra Questions for Class 10 Scientific discipline Affiliate 2 Acids Bases and Salts with Answers Solutions

Acids Bases and Salts Extra Questions Very Brusque Answer Type

Question 1.
2 solutions A and B have pH values of 5 and 8 respectively. Which solution will be basic in nature?
Reply:
Solution B.

Question ii.
If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be washed?
Answer:
The hand should be done immediately with enough of h2o and a paste of sodium hydrogen carbonate (a base) must exist applied to neutralise the acid.

Question iii.
If someone is suffering from the problem of acerbity afterwards overeating; which of the post-obit would you suggest as a remedy?
Lemon juice, Baking soda solution or Vinegar.
Answer:
Baking soda solution considering it is basic in nature and hence neutralises the excess acrid present in the tum.

Question iv.
Arrange the following in the increasing society of acidic strength. Acetic acid, water and hydrochloric acid
Reply:
Water < acetic acid < hydrochloric acid.

Question v.
Why does tooth decay kickoff when the pH of mouth is lower than 5.5 ?
Answer:
Tooth starts decaying when the pH of our mouth is lower than five.v. This is because below this pH value, the medium of the mouth becomes more than acidic due to which molar enamel corrodes at a faster rate.

Question 6.
Ii solutions X and Y take pH values of 3.0 and 9.v respectively. Which of these will turn litmus solution from blue to red and which volition plough phenolphthalein from colourless to pink?
Respond:
Ten will turn blue litmus to reddish because it is acidic in nature having pH value less than seven. Y will turn phenolphthalein from colourless to pinkish because it is bones in nature having pH value. greater than 7.

Question 7.
Why aqueous ammonia solution considered a base although ammonia does not contain hydroxyl (OH-) ion ?
Respond:
Ammonia dissolves in water equally follows:
NH₃ + H₂O → NH₃ ⁺ + OH^–
The hydroxyl ions produced in the solution are responsible for basic character of ammonia.

Question viii.
A knife, which is used to cutting a fruit, was immediately dipped into water containing drops of blue litmus solution. The colour of the solution changes to red, what is the nature of the fruit ?
Answer:
The fruit is acidic every bit it turns blue litmus solution to cherry.

Question 9.
Explain why an aqueous solution of ammonium chloride is acidic in nature.
Answer:
Ammonium chloride (NH₄Cl) is the common salt of a strong acid, hydrochloric acid (HCl), and a weak base of operations ammonium hydroxide (NH₄OH), so an aqueous solution of ammonium chloride is acidic in nature.

Question 10.
What are the products formed when an acrid reacts with a base of operations ?
Answer:
acrid reacts with a base to class salt and water.

Question 11.
Fresh milk has a pH of 6. When it changes into curd (yogurt), will its pH value increase or subtract ? Why?
Answer:
When milk changes into curd (yogurt), its pH value decreases. This is because during curd formation, lactic acrid is produced which makes it acidic.

Question 12.
A white compound becomes hard on mixing proper quantity of water. It is also used in surgery to maintain joints in a fixed position. Name the chemical compound
Reply:
Plaster of Paris (calcium sulphate hemihydrate).

Question 13.
Which ane of these has a higher concentration of H⁺ ions ?
ane M HCl or 1 M CH_threeCOOH
Answer:
1 Yard HCl has a college concentration of H⁺ ions because it is a stronger' acrid than CH₃COOH.

Question fourteen.
In addition to sodium hydrogencarbonate, baking pulverisation contains a substance '10'. Proper noun the substance 'X'.
Answer:
Tartaric acid.

Question xv.
What is the commerClal name of calcium sulphate hemihydrate ?
Reply:
Plaster of Paris.

Question xvi.
Name the substance obtained by the activity of chlorine on dry slaked lime.
Answer:
Bleaching pulverization.

Question 17.
Write two methods of grooming of baking soda forth with the chemical equation.
Reply:
Preparation Method:

Question 18.
Why does the milkiness disappear on passing excess of carbon dioxide to lime h2o ?
Answer:
When carbon dioxide is passed in excess, calcium carbonate (which appears milky) gets converted into calcium hydrogencarbonate which is soluble. Hence, the milkiness disappears.

Question 19.
An aqueous solution turns scarlet litmus solution blue. Excess add-on of which solution would opposite the change ammonium hydroxide solution or muriatic acid?
Answer:
Hydrochloric acid because adding excess acrid to the base would turn blue litmus solution red.

Question 20.
Plaster of Paris should exist stored in moisture proof container. Explain why?
Answer:
Plaster of Paris reacts with moisture and gets hardened due to formation of gypsum so it is stored in moisture proof container.

Question 21.
Why is the electrolysis of a concentrated solution of sodium chloride known as chlor-alkali process?
Answer:
Information technology is because of the products formed : chlor for chlorine and brine for sodium hydroxide.

Question 22.
Write the modernistic definition of acid and base. Requite one example of each.
Reply:
acid : Those substances which give hydrogen ions (H⁺) or hydronium ions (H_iii O⁺) on dissoClation in aqueous solution are called acids, east.g. HCl (aq) \(\rightleftharpoons\) H⁺ + C1^–
Base : Those substances which give hydroxide ions (OH^–) on dissoClation or ionisation in aqueous solution are chosen bases, e.g. NaOH (aq) \(\rightleftharpoons\) Na⁺ + OH^–
Strong acids HCl, H_twoAnd then_iv, HNO₃
Weak Bases NH_fourOH.Al(OH)_three

Question 23.
Explain the method of preparation of bleaching powder.
Answer:
Bleaching powder (CalCl_two) is prepared by action of chlorine on dry slaked lime.

Question 24.
What is pH value ? Describe its importance in our daily life:
Answer:
pH Calibration : It is a calibration used for measuring hydrogen ion concentration. The p in pH stands for potenz which means power in German.
It has values ranging from 0 (very acidic) to xiv (very element of group i). Thus, pH is a number which indicates the acidic or bones nature of a solution.
Importance in everyday life :
(i) Plants and Animals are pH sensitive : Living or ganisms tin survive only in a narrow range of pH change, our torso works commonly within a pH range of 7 to seven.viii.
(2) pH in Our Digestive Organisation : HCl present in the stomach helps is the digestion of food. During indigestion the breadbasket produces also much acid, it couses pain and irritation.

Acids Bases and Salts Extra Questions Short Answer Blazon

Question 1.
What is an olfactory indicator ? Name 2 such indicators.
Answer:
Those substances whose smell (or odour) changes in acidic or basic solutions are called olfactory indicators. Onion and vanilla extract are olfactory indicators.

Question ii.
Proper noun the acid present in the following:
(i) Tomato plant
(2) Vinegar
(iii) Tamarind
Reply:
(i) Cltric acrid
(two) Acerb acrid
(3) Tartaric acrid.

Question three.
List in tabular grade two differences between an acid and a base based on their chemical properties.
Answer:

Question 4.
What happens when a cold and concentrated solution of sodium chloride reacts with ammonia and carbon dioxide ? Write the equation of the reaction which takes place.
Reply:
When a cold and concentrated solution of sodium chloride reacts with ammonia and carbon dioxide, sodium hydrogencarbonate (baking soda) and ammonium chloride is formed.

Question five.
Name the gas evolved when dilute HCl reacts with sodium hydrogen carbonate. How is it recognised ?
Answer:
Co₂ gas is evolved. The reaction is as follows:

When the produced gas is passed through lime h2o, lime water turns milky which confirms that the evolved gas is CO₂.

Question 6.
The pH of soil A is 7.v while that of soil B is 4.5. Which of the ii soils should exist treated with powdered chalk to suit its pH and why?
Answer:
Soil B having pH 4.5 should be treated with powdered chalk to adjust its pH. Soil B is besides acidic. Its acidity can exist reduced by adding powdered chalk (CaCO_iii), which is a base.

Question 7.
Write down the molecular formula and chemical name of Baking soda. Give the chemical equation of its training.
Answer:
Baking Soda : Its chemical proper name is Sodium Hydrogen Carbonate (or Sodium Bicar bonate).
Its molecular formula is NaHCO_iii.
Preparation :
NaCl(aq) + H₂O(l) + CO_two(g) + NH₃(g) → NH₄Cl(g) + NaHCO₃(south)

Question viii.
The conditions preferred by some plants are shown in the table beneath:

(a) Which plants grow well over the largest range of pH values ?
(b) Which plant can abound in the most acidic soil ?
(c) Which plant tin grow in the bones soil only?
(d) What is the pH range for onion to grow well ?
Answer:
(a) Black currant and strawberry
(b) Potato (4.5 – half-dozen.0)
(c) Mint (seven.0 – 8.0)
(d) 6.0 – 7.0

Question 9.
(i) Name the products formed when sodium hydrogencarbonate is heated.
(ii) Write the chemical equation for the reaction involved in it.
Answer:
(i) On heating sodium hydrogencarbonate (NaHCO₃), information technology decomposes to form sodium carbonate (Na_two.CO₃), water (H₂O) and carbon dioxide (CO₂).

Question 10.
Name the acid present in an emmet sting and give its chemical formula. Too requite the mutual method to get relief from the discomfort caused by the ant sting.
Answer:
The acrid nowadays in an ant sting is methanoic acid (formic acrid). The chemical formula is HCOOH. To get relief, i should utilise whatsoever available basic salt, e.chiliad., blistering soda (NaHCO₃) on it.

Question 11.
What happens when nitric acid is added to an eggshell ?
Answer:
Eggshells contain calcium carbonate. When nitric acid is added to it, carbon dioxide gas is evolved. The reaction can exist given as
CaCO_iii + 2HNO_iii → Ca(NO₃)_ii + H₂O + CO₂

Question 12.
When zinc metal is treated with a dilute solution of a potent acrid, a gas is evolved, which is utilised in the hydrogenation of oil. Name the gas evolved. Write the chemical equation of the reaction and also write a examination to find the gas formed.
Answer:
When zinc reacts with dilute solution of stiff acid, it forms salt and hydrogen gas is evolved.
Zn + 2HCl → ZnCl₂ + H₂
When a burning splinter is brought near the oral cavity of the exam tube, the gas burns with a popular sound.

Question 13.
What will be the activeness of the following substances on litmus paper ? Dry HCl gas, Moistened NH, gas, Lemon juice, Carbonated soft drink, Curd, Soap solution.
Answer:

Question 14.
A educatee prepared solutions of
(i) an acid and
(ii) a base in two dissever beakers. She forgot to label the solutions and litmus paper is not available in the laboratory. Since both the solutions are colourless, how will she distinguish between the two ?
Reply:
In the absence of litmus paper, whatsoever indicator like methyl orange, phenolphthalein can exist used. Natural indicator similar turmeric tin also be used.

Question 15.
Which acid is produced in our stomach ? What happens if in that location is an excess of acid in the tum ? How can its effect be cured ?
Answer:
Hydrochloric acid is produced in our stomach. The excess acrid in the tummy causes indigestion which produces pain and irritation. This effect can be cured by using antacids. Antacids (a group of balmy bases) react with excess acid in the stomach and neutralise it.

Question 16.
To the 3 solutions listed below, a few drops of phenolphthalein and bluish litmus were added separately. SpeClfy the color modify in each case, if any:

Answer:

Question 17.
A table salt Ten when dissolved in distilled h2o gives a clear solution which turns scarlet litmus blue. Explicate this phenomenon.
Reply: Basic solutions turn red litmus paper blueish. The salt of a weak acid and a potent base gives a basic solution. Then, the given salt X is the salt of a weak acid and a strong base. . Instance : When sodium carbonate is dissolved in h2o, it gets hydrolysed to some extent and forms sodium hydroxide and carbonic acid.

Being a strong base, sodium hydroxide is fully ionised and gives a large corporeality of hydroxide ions (OH^–). Carbonic acrid is a weak acid which is just slightly ionised and hence, gives a small amount of hydrogen ions (H⁺). The H⁺ ions produced past carbonic acrid neutralises just a small amount of OH-ions produced by sodium hydroxide and the rest amount of OH^–ions are present in the solution. Hence, the Na_two CO₃ solution is basic in nature. It turns cherry litmus blue.

Question xviii.
With the assistance of a chemic equation, explain how a soda-acid fire extinguisher helps in putting out a fire.
Answer:
Soda-acrid fire extinguisher contaisn sodium bicarbonate and sulphuric acrid, which are in split containers in them. When knob of the fire extinguisher is pressed, then sulphuric acrid mixes with sodium bicarbonate solution and produces a lot of CO, gas, which forms a blanket over the fire and cuts it off from the supply of the air to the burning substance and the fire stops.

Question 19.
Give a method of preparation of Plaster of Paris and also requite ane use.
Respond:
The compound prepared from gypsum on heating it at 100°C, is known as Plaster of Paris. Its chemical formula is CaSO_four.\(\frac{1}{two}\) H₂O. Hence, its chemical name is calcium sulphate hemihydrate. The chemical equation for its preparation is every bit follows :

Plaster of Paris is used in hospitals mainly every bit plaster for supporting fractured basic in the right position. In dentistry, it is used for making casts.

Question 20.
What is meant past water of crystallisation ? Explain that the crystalline salts contains water of crystallisation.
Respond:
Water of crystallisation is a stock-still number of water molecules present in one formula unit of a salt. I formula unit of measurement of copper sulphate contains 5 water molecules (5H₂O). The water molecules which grade part of the structure of a crystal are called water of crystallisation. When hydrated salts are heated strongly, they lose their water of crystallisation.
On potent heating, blue copper sulphate crystals plough white (due to the loss of water of crystallisation).

Question 21.
(i) Write the formula and chemical name of bleaching pulverization.
(ii) Write the chemical equation to represent the action of atmospheric CO₂ gas on bleaching powder when left exposed in open.
(iii) Country for what purpose is bleaching powder used in h2o treatment plants.
Answer:
(i) Chemic formula : CaOCl₂
Chemic name : calcium oxychloride

(three) Bleaching powder is used in water treatment plants for disinfecting drinking h2o to make it free of germs.

Question 22.
How would you distinguish between baking pulverisation and washing soda by heating?
Answer:
The chemical formula of baking powder is sodium hydrogencarbonate (NaHCO₃); whereas; that of washing soda is sodium carbonate (Na₂ CO₃.10H₂O).
Sodium hydrogencarbonate on heating gives CO_ii gas which will plow lime h2o milky whereas no such gas is obtained from sodium carbonate.

Question 23.
Table salt A commonly used in baker products on heating gets converted into another salt B which itself is used for removal of hardness of water and a gas C is evolved. The gas C when passed through lime water, turns it milky. Identify A, B and
Answer:
Baking powder (NaHCO₃), table salt A is ordinarily used in baker products. On heating, it forms sodium carbonate (Na₂CO₃), B and CO₂ gas, C is evolved. When CO₂ gas is passed through lime water information technology forms calcium carbonate (CaCO_iii), which is slightly soluble in water making it milky.
A – NaHOCO₃; B — Na₂CO_iii; C — CO₂ gas

Question 24.
What are potent and weak acids ? In the following list of acids, split up strong acids from weak acids; Hydrochloric acid, Cltric acid, acetic acid, nitric acid, formic acid, sulphuric acid.
Answer:
In aqueous solutions, stiff acids ionise completely and provide loftier concentration of hydronium ions. On the other hand, weak acids are partially ionised and an aqueous solution of aforementioned molar concentration provides a much smaller concentration of H_threeO⁺ ions.
Potent acids-Hydrochloric acrid, sulphuric acrid, nitric acid.
Weak acids-Cltric acid, acetic acid, formic acid.

Question 25.
What happens when dilute hydrochloric acid is added to the following and write counterbalanced chemical equations :
(i) Bleaching powder
(ii) Zinc granules
(3) Baking soda
Answer:

Question 26.
Give suitable reason for the following statements :
(i) We feel called-for sensation in the stomach when we overeat.
(two) The crystals of washing soda change to white pulverisation on exposure to air.
(iii) An aqueous solution of sodium chloride is neutral simply an aqueous solution of sodium carbonate is bones.
Reply:
(i) When we overeat excess of acids is produced in the tummy which causes called-for awareness.
(2) Washing soda is sodium carbonate decahydrate which when exposed to air loses ten molecules of water and changes to white powder.
(iii) Sodium chloride is a salt of strong acrid HCl and strong base NaOH, so it is neutral.. Sodium carbonate is a salt of weak acid H₂CO_three and stiff base NaOH, then it is basic.

Question 27.
(i) How is plaster of Paris chemically dissimilar from gypsum ? How tin can they be interconverted ? Write two uses of Plaster of Paris.
(ii) What is the effect of temperature on plaster of Paris?
Respond:
(i) Plaster of Paris is chemically CaSO₄.1/2H₂O, merely gypsum is CaSO_iv.2H₂O. On heating gypsum (CasO_four.2H₂O) at 373 G, it loses water molecules and becomes calcium sulphate hemihydrate (CaSO_four . \(\frac{1}{2}\)H₂O).
On mixing with water, plaster of Paris changes to gypsum one time again leaving a hard solid mass.
Uses :
(a) Information technology is used for making ceiling designs.
(b) It is used for joining the fractured bones.
(2) On heating plaster of Paris, it loses water molecules and becomes calcium sulphate.

Question 28.
Write chemical equation for the grooming of Washing soda and also give its one use.
Answer: Sodium Carbonate is a white crystalline solid. It is called Washing soda. Sodium Carbonate can be obtained past heating baking soda.
NaCO_three(s)+10H₂O(50) → Na_iiCO₃.10H₂O(southward)
Use: It is used in glass, lather and newspaper industries.

Acids Bases and Salts Extra Questions Long Answer Type

Question 1.
(i) In the following schematic diagram for the preparation of hydrogen gas as shown in effigy, what would happen if post-obit changes are made ?
(a) In place of zinc granules, aforementioned amount of zinc dust is taken in the test tube. (b) Instead of dilute sulphuric acid, dilute hydrochloric acid is taken.
(c) Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated.
(ii) How do metallic carbonates and metal hydrogencarbonates react with acids ?

Reply:
(i) (a) Hydrogen gas will evolve with greater speed.
(b) Almost same corporeality of gas is evolved.
(c) If sodium hydroxide is taken, hydrogen gas will be evolved.

(ii) All metallic carbonaes and hydrogencarbonates react with acids to class a respective salt, carbon dioxide and h2o.
Metal carbonate + acid → Table salt + Carbonate dioxide + Water
Metallic hydrogencarbonate + acrid → Salt + Carbon dioxide + Water
For case, sodium carbonate reacts with dilute hydrochloric acid as follows:
Na₂CO₃(due south) + 2HCl (aq) → 2NaCl(aq) + H_twoO(fifty) + CO₂ (k)
Sodium hydrogencarbonate reacts with dilute hydrochloric acid every bit follows:
NaHCO_three(s) + HCl (aq) → NaCl (aq) + H_iiO(fifty) + CO₂(g)

Question 2.
A metallic carbonate X on reacting with an acid gives a gas which when passed through a solution Y gives the carbonate back. On the other hand, a gas Yard that is obtained at anode during electrolysis of brine is passed on dry Y, it gives a chemical compound Z, used for disintifecting drinking h2o. Place X, Y, Thou and Z. [NCERT Exemplar]
Respond:
The gas evolved at anode during electrolysis of brine is chlorine (G).
When chlorine gas is passed through dry out Ca(OH)₂ (Y) produces bleaching pulverization (Z) used for disintifecting drinking water.

Since Y and Z are calcium salts, therefore X is also a calcium common salt and is calcium carbonate :
CaCO_three + 2HCl → CaCl₂ + CO₂ + H_twoO
Ca(OH)₂ + CO_ii → CaCO₂ + H₂O

Question 3.
A sulphate salt of Group 2 element of the Periodic Table is a white, soft substance, which can exist moulded into different shapes past making its dough. When this chemical compound is left in open for some time, it becomes a solid mass and cannot be used for moulding purposes. Identify the sulphate salt and land why does it show such a behaviour. Requite the reaction involved.
Answer:
The substance which is used for making different shapes is Plaster of Paris. Its chemical
proper name is calcium sulphate hemihydrate (CaSO₄ – \(\frac{1}{ii}\)H₂O). The two formula unit of Caso share one molecule of water. As a outcome, it is soft.
When it is left open for some time, information technology absorbs moisture from the atmosphere and forms gypsum, which is a hard solid mass.

Question iv.
Write the formulae of the salts given below:
Potassium sulphate, sodium sulphate, calcium sulphate, magnesium sulphate, copper sulphate, sodium chloride, sodium nitrate, sodium carbonate and ammonium chloride.
Identify the acids and bases from which the in a higher place salts may exist obtained. How many families can yous identify amongst these salts ?
Answer:
The formulae of the given salts and the acids and bases from which these salts may be obtained are given in the following tabular array :

What Happens When ?

Question 1.
Write only the chemical reaction of the following:
(i) Effect of temperature on sodium bicarbonate.
(two) Sodium bicarbonate with muriatic acid.
Answer:

How to obtain ?

Question 1.
Write only the chemical reactions of the following:
(i) Sodium bicarbonate from sodium chloride
(ii) Plaster of Paris from gypsum
Answer:

Distinguish Between Acids And Bases,

Source: https://www.learncram.com/cbse/acids-bases-and-salts-class-10-extra-questions/

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