For aspiring medical professionals, a solid understanding of chemistry is paramount, not only for NEET but to comprehend the complex biochemical processes that occur within the human body. Whether you’re a NEET aspirant or simply passionate about chemistry, this quiz is tailored for you. Dive into these 20 multiple-choice questions and test your grasp on the basic concepts of chemistry!
1. What is the SI unit of mass?
Answer:
Explanation:
The International System of Units (SI) designates kilogram as the unit for mass.
2. Avogadro's number represents the number of atoms in:
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Explanation:
Avogadro's number (6.022 x 10^23) is the number of atoms in exactly 12 grams of carbon-12.
3. The number of atoms in a molecule of water is:
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Explanation:
Water (H2O) consists of 2 hydrogen atoms and 1 oxygen atom.
4. A cation is:
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Explanation:
A cation is an ion that has lost electrons and therefore has a positive charge.
5. What is the molar mass of H2O?
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Explanation:
H2O has 2 hydrogen atoms (2 x 1 g/mol) and 1 oxygen atom (16 g/mol), totaling 18 g/mol.
6. Which of the following represents a chemical change?
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Explanation:
Rusting is a chemical change as it results in the formation of a new substance (iron oxide).
7. The density of a substance is defined as:
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Explanation:
Density is the ratio of mass to volume of a substance.
8. What is the pH of pure water at 25°C?
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Explanation:
Pure water is neutral and has a pH of 7 at 25°C.
9. Which of the following is not an element?
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Explanation:
Water is a compound composed of hydrogen and oxygen.
10. What is the atomic number of carbon?
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Explanation:
The atomic number represents the number of protons. Carbon has 6 protons.
11. An isotope of an element contains:
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Explanation:
Isotopes of an element have the same number of protons but a different number of neutrons.
12. A substance made up of two or more elements chemically combined in a fixed ratio is called:
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Explanation:
Compounds are substances formed when two or more elements combine in a fixed ratio.
13. Which of the following is not a physical change?
Answer:
Explanation:
Combustion is a chemical change as it results in the formation of new substances.
14. The number of molecules in one mole of a substance is:
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Explanation:
One mole of any substance contains Avogadro's number (6.022 x 10^23) of entities.
15. Who is known as the father of modern chemistry?
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Explanation:
Antoine Lavoisier is often referred to as the father of modern chemistry.
16. The atomicity of ozone is:
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Explanation:
Ozone (O3) consists of three oxygen atoms, thus its atomicity is 3.
17. Which of the following is a noble gas?
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Explanation:
Argon belongs to the noble gas group of the periodic table and is chemically inert.
18. The number of valence electrons in chlorine is:
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Explanation:
Chlorine has 7 valence electrons in its outermost shell.
19. What is the empirical formula for glucose (C6H12O6)?
Answer:
Explanation:
The empirical formula represents the simplest whole-number ratio of atoms. For glucose, it is CH2O.
20. Which among the following is an exothermic process?
Answer:
Explanation:
When sodium hydroxide (NaOH) dissolves in water, it releases heat, making the process exothermic.