Find the asnwers for the following questions .1.Name the acid present in the following:
(i) Tomato (ii) Vinegar (iii) Tamarind
2. 15 mL of water and 10 mL of sulphuric acid are to be mixed in a beaker
(i) State the method that should be followed with reason.
(ii)What is this process called?
3.Explain how antacid works.
4. Explain the action of dilute hydrochloric acid on the following with chemical equation:
(i) Magnesium ribbon (ii) Sodium hydroxide (iii) Crushed egg shells
5.State reason for the following statements:
(i) Tap water conducts electricity whereas distilled water does not.
(ii) Dry hydrogen chloride gas does not turn blue litmus red whereas dilute hydrochloric acid does.
(iii) During summer season, a milk man usually adds a very small amount of baking soda to fresh milk.
(iv) For a dilution of acid, acid is added into water and not water into acid.
(v) Ammonia is a base but does not contain hydroxyl group.
6. Name the natural source of each of the following acid
(i) Citric acid. (ii)Oxalic acid.
(iii)Lactic acid. (iv)Tartaric acid.
7.A student detected the pH of four unknown solution A, B, C and D as follows 11, 5, 7 and 2. Predict the nature of the solution.
8. How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal?
9. (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.
10. 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.
Answers
Answer:
1) Citric Acid in
2) Acetic acid
3) Tartaric acid
Q2 (i)
We should mix the sulphuric acid in the water drop by drop and with a constant stirring to avoid any splash and accident. 2- The process is called Dilution.
(ii) This process is called dilution.
Antacids work by counteracting (neutralising) the acid in your stomach. They do this because the chemicals in antacids are bases (alkalis) which are the opposite of acids. A reaction between an acid and base is called neutralisation. This neutralisation makes the stomach contents less corrosive..
In this reaction hydrochloric acid react with magnesium ribbon and form magnesium chloride and hydrogen gas. ... Reaction with crushed egg cell. 2HCl+ CaCO3 ========》CaCl2 + CO2 + H2O. when hydrochloric acid reacts with crushed egg shells and utilise to you formation of calcium chloride carbon dioxide gas and water.