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Rakvi performed an activity by taking ethanoic acid and sodium hydrogen carbonate as shown in the diagram given below. The diagram shows an experimental setup where ethanol is oxidised to ethanoic acid using an oxidizing agent, producing CO2 gas sodium bicarbonate (NaHCO3) may be used to test the acidic nature of the product. Answer the following questions based on the given information: (i) What is the observable change when CO2 gas reacts with lime water in the in this experiment? (ii) Rakvi observed that a salt X is formed with the evolution of gas Y. Identify the salt X and evolved gas Y. (iii) Write the chemical equation of the reaction involved.
(a) Lime water turns milky because carbon dioxide gas reacts with calcium hydroxide solution to form calcium carbonate. Calcium carbonate is insoluble in water and appears as a white precipitate, giving the solution a milky appearance. This reaction is a common laboratory test for the presence of caRead more
(a) Lime water turns milky because carbon dioxide gas reacts with calcium hydroxide solution to form calcium carbonate. Calcium carbonate is insoluble in water and appears as a white precipitate, giving the solution a milky appearance. This reaction is a common laboratory test for the presence of carbon dioxide gas.
(b) When ethanoic acid reacts with sodium hydrogen carbonate, the products formed are sodium ethanoate (X), water, and carbon dioxide gas (Y). The reaction demonstrates the typical acid–carbonate reaction, producing effervescence due to carbon dioxide release. The sodium salt formed is soluble, while the gas evolved can turn lime water milky.
(c) Carbon dioxide released from the reaction is confirmed using lime water. It reacts with calcium hydroxide to form insoluble calcium carbonate, which makes the solution appear milky. The balanced reaction is:
Ca(OH)₂ + CO₂ → CaCO₃ + H₂O. This simple test is widely used to detect carbon dioxide gas.
See lessStudy the figure given below and answer the following questions: (A) Name the process depicted in the diagram. (B) Write the composition of gases collected at anode and the cathode. (C) Write the balanced chemical equation of the reaction taking place in this case. (D) The reaction does not take place if a few drops of dilute sulphuric acid are not added to water. Why?
ANSWER: (A) Electrolytic decomposition of water/electrolysis of water. (B) The gas collected at cathode is hydrogen which is double the volume of oxygen collected at anode. (C) 2H2O (l) + Electric current → 2H2 (g) + O2 (g) When an electric current is passed through water, it undergoes electrolysis.Read more
ANSWER:
(A) Electrolytic decomposition of water/electrolysis of water.
(B) The gas collected at cathode is hydrogen which is double the volume of oxygen collected at anode.
(C) 2H2O (l) + Electric current → 2H2 (g) + O2 (g) When an electric current is passed through water, it undergoes electrolysis. Two molecules of liquid water (2H₂O) decompose to form hydrogen gas (2H₂) and oxygen gas (O₂). Hydrogen collects at the cathode, while oxygen collects at the anode.
(D) Water is not a good conductor of electricity sulphuric acid is added in the water to make, it a good conductor of electricity.
See lessZinc granules on treating with an acid X, form zinc sulphate (ZnSO₄) salt along with the evolution of a gas Y, which burns with a pop sound when brought near to a burning candle. Identify acid X and gas evolved Y:
ANSWER: [C] Explanation: When an acid reacts with a metal, hydrogen gas is liberated. In the given reaction, when dilute sulphuric acid reacts with zinc granules, hydrogen gas is liberated and zinc sulphate solution is formed: Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂ (g) The presence of hydrogen gas is teRead more
ANSWER: [C]
Explanation: When an acid reacts with a metal, hydrogen gas is liberated. In the given reaction, when dilute sulphuric acid reacts with zinc granules, hydrogen gas is liberated and zinc sulphate solution is formed:
Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂ (g)
The presence of hydrogen gas is tested by bringing a lighted candle near it. When a lighted candle is brought near the test tube containing hydrogen gas, it burns with a “pop sound” making a little explosion. Hence, acid “X” is sulphuric acid and gas “Y” is hydrogen gas.
See lessWhen a girl is born, the ovaries already contain thousands of immature eggs. On reaching puberty, some of these start maturing. One matured egg is released every month by one of the ovaries. The two oviducts unite into an elastic bag-like structure known as uterus. (i) Write the site of fertilization in human female. (ii) How does the uterus prepare itself to receive and nurture the growing embryo? Explain.
(i) Fertilization in human females takes place in the fallopian tube (oviduct). (ii) The inner lining of the uterus, called the endometrium, becomes thick, soft, and richly supplied with blood vessels each month. This provides a warm, nutrient-rich environment to receive the fertilized egg and suppoRead more
(i) Fertilization in human females takes place in the fallopian tube (oviduct).
(ii) The inner lining of the uterus, called the endometrium, becomes thick, soft, and richly supplied with blood vessels each month. This provides a warm, nutrient-rich environment to receive the fertilized egg and support the growing embryo.
See lessHow does the developing embryo get nutrition from the mother’s blood? Explain.
The developing embryo gets nutrition from the mother’s blood through a special tissue called the placenta. The placenta forms a connection between the embryo and the mother’s uterus. Tiny finger-like structures, called villi, grow into the uterine tissue, increasing the surface area for exchange. ThRead more
The developing embryo gets nutrition from the mother’s blood through a special tissue called the placenta. The placenta forms a connection between the embryo and the mother’s uterus. Tiny finger-like structures, called villi, grow into the uterine tissue, increasing the surface area for exchange. The mother’s blood vessels surround these villi and supply oxygen, glucose, amino acids, and other nutrients, which diffuse into the embryo’s blood. At the same time, waste products from the embryo pass into the mother’s blood for removal.
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