NIOS April 2024 Chemistry MCQs with Answer
NIOS April 2024 Chemistry MCQs
24 Objective Questions
Question Number 1 to 16
NIOS April 2024 Answer
You answered out of questions correctly.
You got % marks.
NIOS April 2024 Subjective Questions Answer
17. Complete the following by the options given below:
atomic mass; formula mass; molar mass; C-6; C-12; C-14; 0·01; 0·001; 0·0001; integral; fractional: 2
(a) 58·5 g mol–1 is the --- of NaCl.
(b) A mole is the amount of a substance that contains as many entities (atoms, molecules or other particles) as in exactly 12 g of --- isotope.
(c) 1 mm is equal to --- m.
(d) Molecular formula is always --- multiple of the empirical formula.
Answer:
(a) molar mass
(b) C-12
(c) 0·001
(d) integral
18. Read the passage given below and answer the following questions (out of four attempt any two) : 1×2=2
According to VSEPR theory, the electron pairs around the central atom in a molecule arrange themselves in space in such a way that they minimize their mutual repulsion. The lone pair repulsion is much greater than the bond pair repulsion.
(a) Name the electron pairs around the central atom in a molecule who arrange themselves in space in such a way that they minimize their
mutual repulsion.
(b) Which parameter of the molecule is linked to mutual repulsion of electron pairs?
(c) When the number of electron pairs around the central atom is five, which geometry is predicted for the molecule?
(d) Which electron pair is known as the lone pair of electrons in a molecule?
Answer:
(a) Bond Pairs and Lone Pairs.
(b) Molecular geometry (or molecular shape).
(c) Trigonal bipyramidal.
(d) Non-bonding electron pair.
19. Write True (T) for correct statement and False (F) for incorrect statement (out of four attempt any two) : 1×2=2
(a) Benzene-chloroform mixture exhibits positive deviation from Raoult's law.
(b) Boiling point is a colligative property.
(c) Vapour pressure of a liquid is the pressure exerted by the vapour of the liquid in any condition/situation.
(d) Two liquids are miscible when they dissolve in each other in all proportions.
Answer:
(a) False (F) (b) True (T) (c) False (F) (d) True (T)
20. Write True (T) for correct statement and False (F) for incorrect statement (out of four attempt any two) : 1×2=2
(a) In a galvanic cell, electrons always flow from cathode to anode.
(b) Salt bridge is a contact between two half-cells without any mixing of electrolytes.
(c) Higher the valency of the ion, greater is its conducting power.
(d) Conductivity of a cell is the product of conductance and cell constant.
Answer:
(a) False (F) (b) True (T) (c) False (F) (d) True (T)
21. Write True (T) for correct statement and False (F) for incorrect statement (out of four attempt any two) : 1×2=2
(a) The reaction of lithium with water is less vigorous than that of sodium.
(b) The melting and boiling points of alkali metals increase down the group due to increasing size and weak intermetallic bond.
(c) Calcium imparts brick red colour to the flame.
(d) Chlorophyll is a complex compound of magnesium.
Answer:
(a) True (T) (b) False (F) (c) True (T) (d) True (T)
22. Write True (T) for correct statement and False (F) for incorrect statement (out of four attempt any two) : 1×2=2
(a) Sulphur shows two, four and six valencies in its compounds.
(b) Fluorine is prepared by electrolysis of hydrogen fluoride.
(c) Chlorofluorocarbons have very high capacity to retain heat.
(d) The oxidation state of chlorine in chlorous acid is +1.
Answer:
(a) True (T) (b) True (T) (c) True (T) (d) False (F)
23. Write True (T) for correct statement and False (F) for incorrect statement (out of four attempt any two) : 1×2=2
(a) Copper(I) compounds are white and diamagnetic while copper(II) compounds are coloured and paramagnetic.
(b) The common oxidation state of Cu, Ag and Au is +2.
(c) Scandium does not exhibit variable oxidation state in its compounds.
(d) Among Al, Zn, Mg and Fe, the densest element is Fe.
Answer:
(a) True (T) (b) True (T) (c) True (T) (d) False (F)
24. Read the passage given below and answer the following questions (out of four attempt any two) : 1×2=2
Coordination compounds are the compounds in which a central metal ion is attached to a group of surrounding ligands by coordinate covalent bond. Ligands can be monodentate or polydentate. Polydentate ligands are also called chelating ligands. The geometries of coordination compounds are linear, tetrahedral, square planar and octahedral.
(a) [Co(CN)6]−3 and[CoF6]−3 both are octahedral complexes. Then what is
the difference between the two?
(b) Give a chemical test to distinguish between [Co(NH3)5Br]SO4 and [Co(NH3)5SO4]Br.
(c) Name any one chelating agent.
(d) Identify and name the bidentate ligand in [Co(en)2(H2O)(CN)]– complex ion.
Answer:
25. Read the passage given below and answer the following questions (out of four attempt any two) : 1×2=2
Ethers are organic compounds in which an oxygen atom is bonded to two alkyl groups or aryl groups. Ethers have geometry similar to water and alcohols.
(a) Draw the geometry of an ether molecule.
(b) Illustrate the basic nature of ethers with the help of a suitable reaction.
(c) What is the IUPAC name of methyl propyl ether?
(d) How can ethers be prepared by Williamson’s synthesis? Illustrate with an example.
Answer:
26. Read the passage given below and answer the following questions (out of four attempt any two) : 1×2=2
Nitro compounds are those derivatives of hydrocarbons in which a hydrogen atom is replaced by a nitro group. These may be aliphatic or aromatic. Nitroalkanes are divided into primary, secondary or tertiary depending upon the attachment of nitro group to primary, secondary or tertiary carbon atom respectively.
(a) Name the following compound according to the IUPAC nomenclature:
CH3-CH(NO2)-CH(CH3)-CH2-CH3
(b) What happens when propane reacts with nitric acid at 680 K? Give the chemical equation.
(c) Write the reduction of nitrobenzene in alkaline medium.
(d) Compare the boiling points of nitro compounds with the corresponding alkanes. Justify your answer.
Answer:
27. Read the passage given below and answer the following questions (out of four attempt any two) : 1×2=2
Hormones are chemical messengers which are secreted by endocrine glands. They are carried through the blood stream to the target tissues. Vitamins are small organic molecules which are taken in diet and these are required in trace amounts for proper-growth.
(a) Name a female sex hormone and state its function.
(b) Which disease is caused by the deficiency of insulin in humans? Which gland secretes it?
(c) Which water-soluble vitamin’s deficiency causes a disease with symptoms of
(i) cracked lips, scaly skin and
(ii) anaemia, irritability?
(d) Name any two vitamins which are fat-soluble.
Answer:
(a) Estrogen is a female sex hormone. Its primary functions include regulating the menstrual cycle, controlling the development of secondary sexual characteristics (such as breasts), and preparing the uterus for pregnancy.
(b) The disease caused by the deficiency of insulin in humans is diabetes mellitus. Insulin is secreted by the pancreas.
(c) (i) Cracked lips and scaly skin are symptoms of riboflavin (Vitamin B2) deficiency.
(ii) Anaemia and irritability are symptoms of folic acid (Vitamin B9) deficiency.
(d) Two fat-soluble vitamins are Vitamin A and Vitamin D.
28. Read the passage given below and answer the following questions (out of four attempt any two) : 1×2=2
A polymer is a giant molecule formed by intermolecular linkage between same or different types of smaller molecules called monomers. The process by which the monomers get linked up is called polymerization. The polymers can be classified on the basis of origin, structure, method of polymerization and molecular forces.
(a) What are the monomers of Terylene?
(b) Among Buna-S and Neoprene, which one is a copolymer and why?
(c) In which process of polymerization are by-products obtained?
(d) In which categories are polymers classified based on their structure?
Answer:
(a) The monomers of Terylene are terephthalic acid (or its dimethyl ester) and ethylene glycol.
(b) Buna-S is a copolymer because it is made from two different monomers: butadiene and styrene. Neoprene, on the other hand, is a homopolymer of chloroprene.
(c) By-products are obtained in the condensation polymerization process. This process involves the elimination of small molecules such as water, ammonia, or hydrogen chloride.
(d) Polymers are classified based on their structure into three main categories: linear polymers, branched polymers, and cross-linked polymers.
