Grade: 10 Acids, Bases and Salts(Board Papers)
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(a) Write the name given to bases that are highly soluble in water? Give an example. (b) How is tooth decay related to pH?
How can it be prevented? (c) Why does bee sting cause pain and irritation? Rubbing of baking soda on the sting area gives
relief. How?
(a) Alkali; NaOH (or) KOH
(b) Tooth decay starts when the pH of the mouth is lower than 5.5. It can be prevented by using tooth pastes which are
generally basic.
(c) Bee-sting has acid that causes pain and irritation. Baking soda being alkaline neutralises acid and gives relief
(a)Write the chemical name and chemical formula of washing soda.
(b)How is it obtained from sodium chloride? Give equations of the reactions.
(c) Why it is called a basic salt? Give its one use.
Chemical name-sodium carbonate
Formula – Na2CO3. 10 H2O
It is a basic salt because when dissolves in water it gives a strong base NaOH; In glass, paper industry; As cleaning agent; For
removing permanent hardness (any one)
Differentiate between strong and weak acids. Identify the strong and weak acids from the following list of acids. Hydrochloric
acid, acetic acid, formic acid, nitric acid.
Acids which ionize completely in aq. Solution – Strong acids; Acids which ionize partially in aq. Solution – Weak acids;
Hydrochloric acid, Nitric acid – Strong acid; Acetic acid, formic acid – Weak acid.
Describe an activity with diagram to illustrate that the reaction of metal carbonates and metal bicarbonates with acids
produces carbon dioxide. Write the relevant equations of all the reactions that take place. Name any two forms in which
calcium carbonate is found in nature.
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(a) Write the common name of CaOCl2. How is it prepared? Write the chemical equation of the reaction involved in the
process. Give any two uses of it. (b) Write the chemical name of washing soda. How is it prepared? Give the relevant chemical
equations.
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A compound which is prepared from gypsum has the property of hardening when mixed with right quantity of water. (i)
Identify the compound and write its chemical formula. (ii) Write the chemical equation for its preparation. (iii) List any two
uses of the above compound.
Mr. P.H.Ganeshan, Chemistry Teacher
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(i) Name the gas which is liberated when an acid reacts with a metal? How will you test the presence of this gas? (ii) Write the
chemical equation for the reaction of zinc metal With (a) hydrochloric acid and (b) with sodium hydroxide. Write the
chemical name of salt obtained in each case.
(iii) Identify the acid and base for ammonium chloride salt. What would be the nature of this salt? Mention the pH range of
this salt.
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(i) Explain why is hydrochloric acid a strong acid and acetic acid, a weak acid ? How can it be verified? (ii) Explain why
aqueous solution of an acid conducts electricity. (iii) You have four solutions A, B, C and D. The pH of solution A is 6, B is 9, C is
12 and D is 7, (a) Identify the most acidic and most basic solutions. (b) Arrange the above four solutions in the increasing
order of H+ ion concentration. (c) State the change in colour of pH paper on dipping in solution C and D.
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(i) What is meant by the term hydrated salt? (ii) Give two examples of hydrated salt which are white and state their chemical
formula.
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A student dropped few pieces of marble in dilute hydrochloric acid, contained in a test – tube. The evolved gas was then
passed through lime water. What change would be observed in lime water? What will happen if excess of gas is passed
through lime water? With the help of balanced chemical equations for all the changes explain the observations.
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(a) Five solutions A, B, C, D and E when tested with universal indicator showed pH as 4, 1, 11, 7 and 9 respectively. Which
solutions is : (i) neutral (ii) strongly alkaline (iii) strongly acidic (iv) weakly acidic and
(v) Weakly alkaline Arrange the solutions in increasing order of H-ion concentration (b) Name the acid and base from which
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the following salts have been formed. (i) Sodium acetate (ii) Ammonium chloride.
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(a) You are given two solutions A and B. The pH of solution A is 6 and pH of solution B is 8. (i) Identify the acidic and basic
solution (ii) Which solution has more H+ ion concentration? Give reason for your answer. (b) Why is HCl a stronger acid than
acetic acid? Explain.
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(a) Identify the compound of calcium which is yellowish white powder and is used for disinfecting drinking water. Write its
chemical name and formulae. How is it manufactured? Write the chemical equation for the reaction involved. Also list two
other uses of the compound.
(b)Write the balanced chemical equation of chlor-alkali Process.
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Write the chemical name of Na2 CO3. 10H2O and Na2CO3. Write the significance of 10 H2O. Mention the term used for water
molecules attached with a salt. With the help of chemical equation. Explain the method of preparation of both of Na 2 CO3.
10H2O and Na2CO3. Also list two uses of Na2 CO3. 10H2O.
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To the three solutions listed below, a few drops of phenolphthalein and blue litmus were added separately. Specify the color
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change in each case, if any :
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(a) An apparatus has been set up as shown in the figure:
State the observation made when electric current is passed through the solution in the beaker? If the solution is replaced by
glucose solution, what will be the observation on passing electric current? Give reason for your observations in each case.
(b) In a gas jar containing hydrogen chloride gas, a dry blue litmus paper is dropped. What change is observed? Now a blue
litmus paper is moistened and dropped into the gas jar. Giving reason, state what is observed?
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(i) Write the chemical name and formula of sodium salt used as :
(a) baking soda (b) washing soda
(ii) Write an equation to show what happens when baking soda is heated.
(iii) State the reason of using baking soda while making breads and cakes.
(iv) List two uses (other than baking) of baking soda.
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(a) Tooth decay starts when the pH of the mouth is lower than 5.5. Explain how the tooth paste prevents tooth decay. (b)
Name the acids present in: (i) Nettle sting (ii) Curd. (c) State the soil conditions under which a farmer treats the soil of his
field with quick lime or slaked lime.
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(a) You have three solutions - A, B, and C having a pH of 6, 2 and 9 respectively. Arrange these solutions in increasing order of
hydrogen ion concentration. Which of the three is most acidic? What happens to the hydrogen ion concentration in A as it is
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diluted? (b) If someone is suffering from a stomach problem called acidity, why is a solution of baking soda offered as a
remedy? (c) Write chemical name and formula of baking soda.
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(a) Write the chemical name and formula of each of the following. (i) Baking soda (ii) Washing soda (b) How does heating of
baking soda help in making a cake soft and spongy ? (c) List two uses of washing soda.
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(a) Write the chemical formula of each of the following: (i) Plaster of paris (ii) Gypsum (b) How can plaster of Paris be
converted into gypsum? (c) List two uses of plaster of Paris stating the property of this compound responsible for these uses.
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To a solution of sodium hydroxide in a test tube two drops of phenolphthalein are added. (i) State the colour change
observed. (ii) If dil HCl is added drop wise to the solution, what will be the colour change? (iii) On adding few drops of NaOH
solution to the above mixture the colour of the solution reappears. Why?
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A compound ‘X’ is bitter to taste. It is a compound of washing powder and reacts with dilute HCl to produce brisk
effervescence due to a colourless and odourless gas ‘Y’ which turns lime water milky due to the formation of ‘Z’ when excess
of CO2 is passed, milkiness disappears due to formation of ‘P’. Identify ‘X’, ‘Y’, ‘Z’ and ‘P’. Write the equations involved in the
formation of Y, Z and P.
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It has been observed that dry hydrogen chloride gas does not turn blue litmus red whereas hydrochloric acid does. Explain
this observation with the help of an activity and state the reason behind it.
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Write the chemical formula of bleaching powder? Write balanced chemical equation involved in the preparation of bleaching
powder and write its three uses.
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(i) Dry pellets of a base 'X' when kept in open absorbs moisture and turns sticky. The compound is also formed by chlor-alkali
process. Write chemical name and formula of X. Describe chlor-alkali process with balanced chemical equation. Name the
type of reaction occurs when X is treated with dilute hydrochloric acid. Write the chemical equation. (ii) While diluting an
acid, why is it recommended that the acid should be added to water and not water to the acid?
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(a) Bee sting leaves a chemical substance that causes pain and irritation. Name the chemical substance. Identify the type of
substance which may give relief on the stung area when applied on it. (b) Mention the pH value below which tooth decay
begins. How this fall below this value? Explain the ill effect of the acidic medium in the mouth. How can this be prevented? (c)
What are strong acids and weak acids? Give an example of each.
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Write balanced chemical equations for the following reactions: (a) dilute sulphuric acid reacts with aluminium powder (b)
dilute hydrochloric acid reacts with sodium carbonate (c) Carbon-di-oxide is passed through lime water.
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(a) State the chemical name and formula of bleaching powder. Write the chemical equation for its preparation. Also mention
its two uses other than bleaching. (b) There are three test tubes A, B, C. Test tube A has an acidic solution, test tube – B has a
basic solution and test tube – C has distilled water. Identify the contents of each test tube with the help of litmus paper.
Mr. P.H.Ganeshan, Chemistry Teacher
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(a) A metal compound ‘X’ reacts with dil. H2SO4 to produce effervescence. The gas evolved extinguishes a burning candle. If
one of the compound formed is calcium sulphate, then what is ‘X’ and the gas evolved? Also write a balanced chemical
equation for the reaction which occurred.
(b) (i) Name one antacid. How does it help to relieve indigestion in stomach? (ii) A farmer treats the soil with quick lime or
calcium carbonate. What is the nature of soil? Why does the farmer treat the soil with quick lime?
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Write the names of the products formed when zinc reacts with NaOH. Also write the balanced chemical equation for the
reaction involved. Write a test to confirm the presence of the gas evolved during this reaction.
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How is sodium hydroxide produced? Write the balanced chemical equation also Why is this process called as chlor – alkali
process? In this process name the products given off at: (a) anode (b) cathode Write one use of each of these products.
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What is water of crystallization? Write the common name and chemical formula of a commercially important compound
which has ten water molecules as water of crystallization. How is this compound obtained? Write the chemical equation also.
List any two uses of this compound.
Mr. P.H.Ganeshan, Chemistry Teacher
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(a) State one example of a synthetic indicator and an olfactory indicator?
(b) How do bacteria decay our teeth? Why do we basic tooth pastes for cleaning our teeth?
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A compound ‘X’ is used in the kitchen for making crispy pakoras. Identify the compound and write its common name and
chemical formula. Write the chemical equation of the process by which ‘X’ is produced. What is the nature of compound X?
State one use of ‘X’ based on its nature. Name the powder or mixture obtained by mixing ‘X’ with tartaric acid. Why is this
mixture/powder added to cakes?
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Describe an activity to show that the crystals of copper sulphate contain water of crystallization. Write the formula of
hydrated copper sulphate. Define water of crystallization. State two more examples of salts which have the water of
crystallization.
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Write the chemical name and formula of washing soda. How is it prepared? Write balanced chemical equation of the reaction.
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(a) You have two solutions X and Y. the pH of solutions X is 5 and pH of solution Y is 8. Which solution has more hydrogen ion
concentration? Which of this is acidic and which one is basis?
(b) While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid? (c) Write
the balanced chemical equation for the action of granulated zinc with sodium hydroxide. Name the products formed.
Mr. P.H.Ganeshan, Chemistry Teacher
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(a) Write the chemical reaction of metal carbonates with acid. What happens on passing this gas evolved above, over lime
water? Write the chemical equation for it. (b) Give the reaction involved in the manufacture of caustic soda by chlor – alkali
process. How can this reaction be used simultaneously for the manufacture of HCl acid? Why is it called chlor-alkali process?
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Give reasons: (i) Copper vessels develop a green coating when exposed in air.
(ii) Acids like HCl and HNO3 show acidic characters in aqueous solutions while solutions of compound like alcohol and
glucose do not show acidic character. (iii) Dry HCl gas does not change the colour of the dry litmus paper.
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(a) What is a neutralization reaction? Give two examples.
(b) Metal compound ‘A’ reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning
candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
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A metal is treated with dilute sulphuric acid. The gas evolved is collected by a method as shown in the figure.
Answer the following questions: (a) Name the gas. (b) Is the gas soluble or insoluble in water?
(c) Is the gas lighter or heavier than air? Justify your answer with reason in each case.
Mr. P.H.Ganeshan, Chemistry Teacher
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(a) Identify the compound of calcium which is yellowish white powder and is used for disinfecting drinking water. Write its
name and formula. How is it manufactured? Write chemical equation for the reaction involved. Mention one more use of the
compound. (b) Write balanced equation for the preparation of the following salts : (c) (i) NaNO 3 (ii) K2SO4
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(a) Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCl) is added to test tube A while
acetic acid (CH3COOH) is added to test tube B. In which test tube will fizzing occur vigorously and why? Write equation to
show the gas evolved. (b) Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Justify your
answer. Why a milkman does adds a small amount of baking soda to fresh milk?
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Demonstrate by an experiment that acid reacts with metal carbonate to liberate carbon dioxide gas.
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(a) What are olfactory indicators? Give an example. (b) Name two naturally occurring acids and mention their source. (c) Zinc
reacts with HCl and NaOH both to produce H2 gas. Write balanced equation for both reactions.
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Give reasons: (a) Acid must be added to water and not vice versa during dilution. (b) Solution of sulphuric acid conducts
electricity whereas alcohol does not. (c) Cakes rise on adding baking powder. (d) Dry ammonia gas has no action on litmus
paper but a solution of ammonia in water turns red litmus paper blue. (e) Tartaric acid is an ingredient of baking powder.
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(a) What is water of crystallization in a substance? Suggest a method to show that the blue copper sulphate crystals contain
water of crystallization. (b) How is plaster of Paris prepared? Give its chemical formula.
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In an activity to investigate whether all compounds containing hydrogen are acidic.
(a) Draw a well labelled experimental set – up for the activity. (b) State what is observed giving reasons for the following
when.
(i) Current is passed through dilute hydrochloric acid in the beaker. (ii) Current is passed through glucose and alcohol
solutions in the beaker.
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(a) With the help of a labelled diagram demonstrate an experiment to show the reaction between sodium carbonate and
dilute hydrochloric acid.
(b) Name the gas evolved. (c) Suggest the test for the gas evolved. (d) Write equation for the chemical reactions involved.
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(a) Explain why (i) Dry crystals of copper sulphate changes colour on heating. (ii) Fresh milk has a pH of 6. This value of pH
decreases when milk is changed into curd. (iv) Tartaric acid helps in making cake or bread soft and spongy. (b) Doctor apply
wet surgical bandages on the fractured bones of a patient for supporting them in right position. What changes are likely to
occur? Write chemical equation for the reaction involved.
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A solution of a substance ‘X'is used for testing carbon dioxide. Identify ‘X'. What will be its reaction with carbon dioxide?
Write balanced equation for the reaction?
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(a) What are antacids? State their role in the treatment of indigestion. (b) What happens when an acid is added to water?
Explain with the help of equation. Give two examples of naturally occurring acid and also mention its source.
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(i) Write balanced chemical equations only for the following chemical properties of acids: (a) when an acid reacts with a
metal.(b) when an acid reacts with a metal bicarbonate. (c) when an acid reacts with a base. (ii) Three solutions A, B and C
have pH values 5, 8 and 10 respectively.
Amongst the three which solution has maximum hydrogen ion concentration? Classify the nature of the three solutions as
acidic or basic.
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(a) Study the following chemical equation : -
Name the reactant and the product and mention one use of the product.
(b) The following salts are formed by the reaction of an acid with a base: (i) Sodium chloride
(ii) Ammonium nitrate. Identify the acid and the base and tabulate your answer in the format given below.
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Naman and Raghav perform an experiment in which they mix concentrated sulphuric acid with water. Naman mixes water to
acid and Raghav mixes acid to water slowly with constant stirring. Mention the suitable reason for selecting the one which
you find is a correct method and discarding the one which is wrong.
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Two test tubes A and B are taken containing solid sodium carbonate and sodium hydrogen carbonate respectively. Some
dilute HCl is poured in both the test tubes. (i) Name the main products formed with their chemical formula in A and B. (ii)
State the similarity between both the activities. (iii) Name the compound that is formed when electricity is passed through an
aqueous solution of the main product obtained in the above mentioned activity. (iv) State your observation with a balanced
chemical equation when the gas evolved in test tube B during the activity passes through lime water.
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