Class 10 Science Chapter 4 MCQ for 2020-2021
| Class: 10 | Science |
| Chapter: 4 | Multiple Choice Questions (MCQ) Tests |
Class 10 Science Chapter 4 MCQ with Answers
Class 10 Science Chapter 4 MCQ Online tests practice with answers and explanation. Practice here to prepare your school test and board papers. Questions are taken form NCERT Books and answers are also confined to NCERT textbooks only.
Q1
Badal appeared in class test but he confused to know the correct statement. Would you help him to know that?
[A]. If we burn diamond in oxygen, then only carbon dioxide gas is formed and nothing is left behind.
[B]. Diamond does not conduct electricity.
[C]. Diamond and graphite are the two common allotropes of carbon which are known to us for centuries.
[D]. All the above.
Answer: Option D
Explanation:Here, all these statements are correct. Hence, your answer will be option [D].
Q2
In a science quiz competition, Deepti asked a question where she had to choose the statement which was/were incorrect?
[A]. The diamond crystal is, therefore, made up of carbon atoms which are powerfully bonded to one another by a network of covalent bonds.
[B]. The melting point of diamond is also very high, being more than 3500°C.
[C]. Diamond is a conductor of electricity as there are ‘free electrons’ in a diamond crystal.
[D]. None of the above.
Answer: Option C
Explanation:A carbon atom has 4 valence electrons in it. Now, in a diamond crystal, each carbon atom is linked to four other carbon atoms by covalent bonds, and hence all the 4 valence electrons of each carbon atom are used up in forming the bonds. Since there are ‘no free electrons’ in a diamond crystal, it does not conduct electricity.
Q3
Mineral acids are stronger acids than carboxylic acids because:
[A]. Mineral acids are completely ionized, carboxylic acids are partially ionized.
[B]. Carboxylic acids are completely ionized, mineral acids are partially ionized.
[C]. Mineral acids are completely ionized, carboxylic acids are completely ionized.
[D]. Mineral acids are partially ionized, Carboxylic acids are partially ionized.
Answer: Option A
Explanation:Mineral acids are strong acids which ionise almost completely and carboxylic acids are weak acids which ionise only partially.
Q4
Which of the following statement is or are incorrect?
[A]. The compounds of carbon are known as organic compounds.
[B]. Although oxides of carbon (like carbon monoxide and carbon dioxide), carbonates, hydrogen carbonates and carbides are also carbon compounds and they are considered to be organic compounds.
[C]. Most of the carbon compounds are non-conductors of electricity.
[D]. Carbon compounds (or organic compounds) are covalent compounds having low melting points and boiling points.
Answer: Option B
Explanation:Though oxides of carbon (like carbon monoxide and carbon dioxide), carbonates, hydrogen carbonates and carbides are also carbon compounds but they are not considered to be organic compounds. This is because their properties are very different from those of the common organic compounds.
Q5
The soap molecule has a
[A]. Hydrophilic head and a hydrophobic tail
[B]. Hydrophobic head and a hydrophilic tail
[C]. Hydrophobic head and a hydrophobic tail
[D]. Hydrophilic head and a hydrophilic tail
Answer: Option A
Explanation:A soap molecule is made up of two parts: a long hydrocarbon part and a short ionic part -COO-Na+ group. The long hydrocarbon chain is hydrophobic (water repelling) and ionic portion is hydrophilic (water attracting).
Q6
Bikash is doing his homework which is given by his teacher. Would you help him to choose the correct sentences?
[A]. The ethene molecule (C2H4) is made up of 2 carbon atoms and 4 hydrogen atoms.
[B]. Each carbon atom shares three electrons with three hydrogen atoms to form three carbon-hydrogen single covalent bonds.
[C]. In ethane, the two carbon atoms share one pair of electrons among themselves to form one carbon-carbon single covalent bond.
[D]. All the above.
Answer: Option D
Explanation:Here, all these statements are correct. Hence, your answer will be option [D].
Q7
Which of the following statement is or are correct?
[A]. A saturated hydrocarbon containing single bonds is indicated by writing the word “ane” after the stem.
[B]. An unsaturated hydrocarbon containing a double bond is indicated by writing the word “ene” after the stem.
[C]. An unsaturated hydrocarbon containing a triple bond is indicated by writing the word “yne” after the stem.
[D]. All the above.
Answer: Option D
Explanation:Here, all the statements are correct. Hence, your answer will be option [D].
Q8
Recently, in a science class test, you are asked a question where you have to say whether the statements are correct or not?
[A]. Any two adjacent homologous differ by 1 carbon atom and 2 hydrogen atoms in their molecular Formulae.
[B]. The difference in the molecular masses of any two adjacent homologous is 16 u.
[C]. All the compounds of a homologous series show similar chemical properties.
[D]. The members of a homologous series show a gradual change in their physical properties with increase in molecular mass.
Answer: Option B
Explanation:It is the characteristics of a Homologous Series is that the difference in the molecular masses of any two adjacent homologous is 14 u. For example, the molecular mass of methane (CH4) is 16 u, and that of its next higher homologue ethane (C2H6) is 30 u. So, the difference in the molecular masses of ethane and methane is 30 – 16 = 14 u.
Q9
Pooja is writing some statements but she confused to know whether the statements are correct or not? If you know the answer to this question, then tell her:
[A]. The alcohol group is made up of one oxygen atom and one hydrogen atom joined together.
[B]. That the elements chlorine, bromine and iodine are collectively known as halogens, so the chloro group, bromo group and iodol group are called halo groups.
[C]. An atom or ‘a group of atoms which makes a carbon compound (or organic compound) reactive and decides its properties (or functions) is called a functional group.
[D]. The carbon compounds (or organic compounds) containing carboxylic acid group (—COOH group) are called mineral acids.
Answer: Option D
Explanation:The carbon compounds (or organic compounds) containing carboxylic acid group (—COOH group) are called carboxylic acids. Carboxylic acids are commonly known as organic acids. Another name for carboxylic acids is alkanoic acids. The carboxylic acids or organic acids are made up of three elements: carbon, hydrogen and oxygen. The simplest carboxylic acid (or organic acid) is formic acid, HCOOH, which is also known as “Methanoic acid”.
Q10
Carbon exists in the atmosphere in the form of:
[A]. Only carbon monoxide
[B]. Carbon monoxide in traces and carbon dioxide
[C]. Only Carbon dioxide
[D]. Coal
Answer: Option C
Explanation:Carbon exist in the atmosphere in the form of carbon dioxide gas (CO2) in air (only 0.03%). Carbon also occurs in the earth’s crust in the form of minerals like carbonates. It also occurs in the form of fossil fuels, organic compounds, wood, cotton and wool etc.
Why does Carbon not form an ionic bonds?
There are two main reasons for not forming an ionic bonds.
- It could gain four electrons forming C4– anion. But it would be difficult for the nucleus with six protons to hold on to ten electrons, that is, four extra electrons.
- It could lose four electrons forming C4+ cation. But it would require a large amount of energy to remove four electrons leaving behind a carbon cation with six protons in its nucleus holding on to just two
electrons.
Why are covalent compounds poor conductors of electricity?
Covalent compounds are formed by the sharing of electrons. Since the electrons are shared between atoms and no charged particles are formed, such covalent compounds are generally poor conductors of electricity.
What is meant by catenation?
The unique ability to form bonds combining one atom with other atoms of carbon, giving rise to large molecules is called catenation.
What is Glacial acid?
The melting point of pure ethanoic acid is 290 K and hence it often freezes during winter in cold climates. This gave rise to its name glacial acetic acid.
What are isomers?
Compounds with identical molecular formula but different structures
are called structural isomers.
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