Gyan Bharti Online Test For Class 10th
Class :- 10th Sub. :- Science FM :- 25 marks
Questions and Answers
- 1.
What will happen if a solution of sodium hydrocarbonate is heated? Give the equation of the reaction involved.
- 2.
Give two important uses of washing soda and baking soda.
- 3.
Which of the statements about the reaction below are incorrect? 2PbO (s) + C (s) → 2Pb (s) + CO2 (g) (a) Lead is getting reduced. (b) Carbon dioxide is getting oxidised. (c) Carbon is getting oxidised. (d) Lead oxide is getting reduced.
- A.
(a) and (b)
- B.
(a) and (c)
- C.
(a) , (b) and (c)
- D.
All
Correct Answer
A. (a) and (b)Explanation
In the given reaction, lead oxide (PbO) is being reduced to lead (Pb), which means that lead is gaining electrons and its oxidation state is decreasing. Therefore, statement (a) is incorrect. On the other hand, carbon (C) is being oxidized to carbon dioxide (CO2), which means that carbon is losing electrons and its oxidation state is increasing. Therefore, statement (b) is also incorrect.Rate this question:
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- 4.
What happens when dilute hydrochloric acid is added to iron filings? Tick the correct answer.
- A.
Hydrogen gas and iron chloride are produced.
- B.
Chlorine gas and iron hydroxide are produced.
- C.
No reaction takes place.
- D.
Iron salt and water are produced.
Correct Answer
A. Hydrogen gas and iron chloride are produced.Explanation
When dilute hydrochloric acid is added to iron filings, a chemical reaction occurs. The hydrogen ions from the hydrochloric acid react with the iron to form hydrogen gas, while the chloride ions combine with the iron to form iron chloride. Therefore, the correct answer is that hydrogen gas and iron chloride are produced.Rate this question:
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- 5.
A shiny brown-coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ ________ and the black coloured compound formed ________
Correct Answer
copper (Cu)
copper oxide (CuO)Explanation
When the shiny brown-colored element "X" is heated in air, it undergoes a chemical reaction and forms a black-colored compound. This indicates that the element "X" is copper (Cu) and the black-colored compound formed is copper oxide (CuO).Rate this question:
- 6.
What is the common name of the compound CaOCl2?
- A.
Washing soda
- B.
Baking soda
- C.
Plaster of paris
- D.
Bleaching powder
Correct Answer
D. Bleaching powderExplanation
CaOCl2 is commonly known as bleaching powder. It is a white powder that is used for various purposes, including bleaching fabrics and disinfecting water. The compound is a mixture of calcium hypochlorite (Ca(ClO)2) and calcium chloride (CaCl2), which gives it its bleaching properties.Rate this question:
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- 7.
Name the substance which on treatment with chlorine yields bleaching powder?
- A.
Calcium oxide
- B.
Calcium hydroxide [Ca(OH)2]
- C.
Calcium carbonate
- D.
Calcium sulphate
Correct Answer
B. Calcium hydroxide [Ca(OH)2]Explanation
Calcium hydroxide is the substance that, when treated with chlorine, yields bleaching powder. Bleaching powder is a mixture of calcium hypochlorite (Ca(ClO)2) and calcium chloride (CaCl2), which are formed when chlorine gas reacts with calcium hydroxide. The reaction between chlorine and calcium hydroxide produces calcium hypochlorite, which is the active ingredient in bleaching powder and is responsible for its bleaching and disinfecting properties.Rate this question:
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- 8.
Name the sodium compound which is used for softening hard water.
- A.
Baking soda
- B.
Baking powder
- C.
Washing soda
- D.
Gypsum
Correct Answer
C. Washing sodaExplanation
Washing soda, also known as sodium carbonate, is used for softening hard water. It is a common household product that can be added to laundry to help remove stains and soften water. Washing soda works by reacting with the minerals in hard water, such as calcium and magnesium, to form insoluble compounds that can be easily rinsed away. This helps to prevent the build-up of mineral deposits on clothes and in washing machines, resulting in cleaner and softer laundry.Rate this question:
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Mar 07, 2023Quiz Edited by
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Jun 10, 2020Quiz Created by
Abdul Baqui
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