Chemical formula of cooking soda is
- A.NaCl
- B.NaOCl
- C.Na2CO3
- D.NaHCO3
Correct answer
Explanation
The correct answer is D, NaHCO3. Cooking soda, also called baking soda, is sodium hydrogen carbonate, also known as sodium bicarbonate. It is a mild base made from one sodium, one hydrogen, one carbon and three oxygen atoms. When it is heated, or when it meets an acid such as curd or lemon juice, it releases carbon dioxide gas. The bubbles of this gas make cakes, dhokla and bread soft and spongy. Baking powder is baking soda mixed with a mild edible acid such as tartaric acid. The same compound is used as an antacid to relieve acidity and in some fire extinguishers. Option A is wrong because NaCl is common salt, sodium chloride. Option B is wrong because NaOCl is sodium hypochlorite, the bleaching liquid; bleaching powder itself is a calcium compound. Option C is wrong because Na2CO3 is washing soda, sodium carbonate, used for cleaning and softening hard water. Exam tip: baking soda NaHCO3, washing soda Na2CO3·10H2O, common salt NaCl.
Practice Questions
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- A.1,2 and 3
- B.2 and 4
- C.1 and 3 only
- D.1 only
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- A.Joule
- B.Watt-hr
- C.Newton-metre
- D.kg-metre/sec²
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- A.Magnesium
- B.Zinc
- C.Aluminium
- D.Lead
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Read the full explanation →In an electric circuit, a wire of resistance 10 Ω is used. If this wire is stretched to a length double of its original value, the current in the circuit would become :
- A.half of its original value.
- B.double of its original value.
- C.one-fourth of its original value.
- D.four times of its original value.
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Read the full explanation →Which one of the following scientists mentioned that an electron in an atom could revolve in certain stable orbits without the emission of radiant energy ?
- A.Ernest Rutherford
- B.J.J. Thomson
- C.Niels Bohr
- D.Albert Einstein
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