Class 10 Science Acid base and Salts Short Questions( One and two Marks)
In this page we have Class 10 Science Acid base and Salts Short Questions( One and two Marks) . Hope you like them and do not forget to like , social shar
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One Mark Questions
Question 1) Why does the flow of acid rain water into a river make the survival of aquatic life in the river difficult? Question 2) Write balanced chemical equations for the reactions taking place when dry blue crystals of copper sulphate are dropped into concentrated sulphuric acid. Question 3) Name the products formed when sodium hydrogen carbonate is heated. Write the chemical equation for the reaction involved. Solution
Formula of sodium hydrogen carbonate is NaHCO3.
when it is heated it forms water , carbon dioxide and and sodium carbonate.
2NaHCO3 --> H2O + CO2 + Na2CO3
Question 4) Two solutions A and B have pH values of 5 and 8 respectively. Which solution will be basic in nature? Solution
Solution B as pH > 7
Question 5) Why does tooth decay start when the pH of mouth is lower than 5.5? Question 6) How is the concentration of hydronium ions (H3O+) affected when a solution of an acid is diluted? Question 7) Fresh milk has a pH of 6. When it changes into curd (Yogurt), will its pH value increase or decrease? Why? Solution
Fresh milk has a pH of 6, before conversion. When milk is turned into curd then its pH value will decrease due to the production of lactic acid in curd which is acidic in nature.
8) A dry pellet of a common base B, when kept in open absorbs moisture and turns sticky. The compound is also a by – product of chlorine – alkali process. Identify B. What type of reaction occurs when B is treated with an acidic oxide? Write a balanced chemical equation for one such solution.
9) Name the acid present in an ant sting.
Two Marks Questions
Question 1) Write the chemical formula for bleaching powder. How is bleaching powder prepared? For what purpose is it used in paper factories? Question 2) (i) An aqueous solution has a pH of 7.0. Is this solution acidic, basic or neutral?
(ii) Which has higher pH value, 1 M HCI or 1 M NaOH? Solution
ii) NaOH has more pH value
Question 3) Name the gas which is usually produced when dilute sulphuric acid reacts with a metal. Illustrate it with an example. How will you test the evolution of this gas? Question 4) A metal compound ‘A’ reacts with dilute sulphuric acid to produce a gas which extinguishes a burning candle. Identify the compound ‘A’ and the a gas produced. Write a balanced chemical equation for the reaction if one of the compounds formed in the reaction is sodium sulphate. Question 5) State what happens when zinc granules are heated with sodium hydroxide solution. Write the balanced equation for this reaction. Name the main product formed in this reaction. Question 6) Give reasons for the following:
(a) Dry HCI does not change the colour of dry litmus paper.
(b) Aqueous solution of an acid conducts electricity. Solution
The colour of litmus paper changes only in the presence of ions like hydrogen (H+) or hydronium (H3O+) ions. HCl can produce these ions only in the form of aqueous solution. Hence dry HCl gas does not change the colour of dry litmus paper
Question 7) While diluting an acid, why is it recommended that acid should be added to water and not water to the acid? Question 8) P and Q are aqueous solution of sodium chloride and sodium hydroxide respectively. Which of these will turn:
(a) Blue litmus to red or
(b) Red litmus to blue? Give justification for your answer. Solution
Solution P no effect on litmus paper since it is neutral
Solution Q it is strong base so it turns red to blue litmus
Question 9) What is universal indicator? State the purpose for which this indicator is used. Question 10) Name the acid produced in our stomach. What happens if there is an excess of acid in the stomach? How can it be cured? Name one antacid. Solution
our stomach produces hydrochloric acid. It helps in the digestion of food without harming the stomach.During indigestion the stomach produces too much acid and this causespain and irritation. To get rid of this pain, people use bases called antacids. These antacids neutralise the excess acid.Magnesium hydroxide (Milk of magnesia), a mild base, is often used for this purpose
Question 11) Define an acid and a base. Name one weak acid and one strong base. Question 12) Explain why an aqueous solution of sodium sulphate is neutral while an aqueous solution of sodium carbonate is basic in nature. Solution
Because Sodium sulphate salt is made by reaction of sulphuric acid (strong acid) the sodium hydroxide (strong base) , thus on combining the opposite effects of acid and base neutralize each others effect completely leading to the formation of a neutral salt.
Sodium carbonate salt is made of reaction of carbonic acid and sodium hydroxide . on combining the basic character will be more as a week acid can not neutralize a strong base completely . so the salt formed is basic in nature
Question 13) How does the enamel of the teeth undergo damage due to the eating of chocolates? What should be done to prevent it? Question 14) (a) Three acidic solutions A, B and C have pH = 0, 3 and 5 respectively.
(i) Which solution has the highest concentration of H+ ions?
(ii) Which solution has the lowest concentration of H+ ions?
(b) How concentrated sulphuric acid can be diluted? Describe the process. Solution
Solution A has highest concentration of H+ ions and Solution C has the lowest concentration of H+ ions
concentrated sulphuric acid can be diluted using water. We need to add small amount of acid in the water not the water to the acid.
Question 15) Fresh milk has a pH of 6. How do you think the pH will change to curd? Explain. Question 16) State in brief the method of preparation of bleaching powder. Give a balanced chemical equation of the reaction involved. Question 17) Give two uses of baking soda and washing soda each. Question 18)When zinc metal is treated with a dilute solution of a strong acid, a gas is evolved, which is utilized in the hydrogenation of oil. Name the gas evolved. Write the chemical equation of the reaction and also write a test to detect the gas formed. Question 19) State for what purpose is bleaching powder used in water treatment plants. Question 20) How would you distinguish between baking powder and washing soda by heating? Question 21) Salt A commonly used in bakery 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 C. Question 22) What are strong and weak acids? In the following list of acids, separate strong acids from weak acids: Hydrochloric acid, citric acid, acetic acid, nitric acid, formic acid, sulphuric acid. Solution
A strong acid dissociates completely (100%)
A weak acid is only partly dissociated (less than 100%)
A strong acid has a pH 1.
pH of weak acid is 3-5
Hydrochloric acid, sulphuric acid.
Acetic acid, Formic acid
All the HCl molecules becomes into hydrogen ions & chloride ions when they are dissolved in water
Some of the acid molecules become ions. most of them stay as acid molecules