In this article, the engineering section bring to you a set of 30 questions based on the latest pattern of JEE Main 2018. This paper will help you to track your progress.
About the paper:
1. There are 30 objective type questions with only one correct option in this paper.
2. Questions have been taken from different topics like Basic Concepts of Chemistry, Structure of Atom, Chemical Bonding and Molecular Structure, States of Matter, Thermodynamics, Solid State, Solutions, Electrochemistry, Chemical Kinetics, Surface Chemistry, Isolation of Elements, p-Block Elements, d and f-Block Elements, Coordination Compounds, Haloalkanes and Haloarenes, Alcohols, Phenols and Ethers, Aldehydes, Ketones and Carboxylic Acids, Organic Compounds containing Nitrogen, Biomolecules, Polymers, Chemistry in Everyday Life
3. Detail solution for all the questions.
Few sample questions from the Solved Practice Paper are given below:
Which of the following solids is not an electrical conductor?
1. Mg (s)
2. TiO (s)
3. I2 (s)
4. H2O (s)
(a) Only 1
(b) Only 2
(c) 3 and 4
(d) 2, 3 and 4
Iodine is a non-polar molecular solid in which iodine molecules are held together by
London force or dispersion force. This is soft and non-conductor of electricity.
Water is a hydrogen bonded molecular solid in which H and 0 are held together by polar covalent bond and each water molecule held together by hydrogen bonding. Due to non-ionic nature, they are not electrical conductor.
Which of the following statements is correct?
(a) Some tranquilizers function by inhibiting the enzymes which catalyse the degradation of noradrenaline
(b) Tranquilizers are narcotic drugs
(c) Tranquilizers are chemical compounds that do not affect the message transfer from nerve to receptor
(d) Tranquilizers are chemical compounds that can relieve pain and fever
Tranquilizers are used for the treatment of stress, fatigue, mild and severe mental diseases. They relieve anxiety, stress, irritability or excitement by inducing a sense of well-being. Noradrenaline is one of the several neurotransmitters which play an important role in mood changes.
If the level of noradrenaline in the body is low for some reasons, then the message transfer process becomes slow and the person suffers from depression. In such cases, antidepressant drugs are used. These drugs inhibit the enzymes which catalyse the degradation of noradrenaline.
If the enzyme is inhibited, then the neurotransmitter noradrenaline is slowly metabolised and can thus activate the receptor for longer periods there by counteracting the effect of depression Tranquilizer form an essential component of sleeping pills.
Which of the following statement is not correct for the catalyst?
(a) It catalyses the forward and backward reactions to the same extent
(b) It alters ΔG of the reaction
(c) It is a substance that does not change the equilibrium constant of a reaction
(d) It provides an alternate mechanism by reducing activation energy between reactants and products
(a) It catalyses the forward and backward reaction to the same extent as it decreases energy of activation hence, increases the rate of both the reactions.
(b) Since, reaction quotient is the relation between concentration of reactants and products. Hence, catalyst does not alter Gibbs free energy as it is related to reaction quotient. Thus, Gibbs free energy does not change during the reaction when catalyst is added to it.
ΔG = – RT ln Q
where, Q = reaction quotient
(c) It doesn't alter equilibrium of reaction as equilibrium constant is also concentration dependent term.
(d) It provides an alternate mechanism by reducing activation energy between reactants and products.
Which one of the following statements related to lanthanons is incorrect?
(a) Europium shows +2 oxidation state.
(b) The basicity decreases as the ionic radius decreases from Pr to Lu.
(c) All the lanthanons are much reactive than aluminium.
(d) Ce (+4) solutions are widely used as oxidizing agent in volumetric analysis.
The first few members of the lanthanoid series are quite reactive, almost like calcium. However, with increasing atomic number, their behavior becomes similar to that of aluminium.
Which of the following process is not responsible for the presence of electric charge on the sol particles?
(a) Electron capture by sol particles
(b) Adsorption of ionic species from solution
(c) Formation of Helmholtz electrical double layer
(d) Absorption of ionic species from solution
Absorption of ionic species from solution is not responsible for the presence of electric charge on the sol particles. Charge on the sol particles is due to
(i) electrons capture by sol particles during electro dispersion of metal.
(ii) preferential adsorption of ionic species from solution.
(iii) formation of Helmholtz electrical double layer.
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
(a) They have high melting points in comparison to pure metals
(b) They are very hard
(c) They retain metallic conductivity
(d) They are chemically very reactive
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals.
(i) They are very hard and rigid.
(ii) They have high melting point which are higher than those of the pure metals.
(iii) They show conductivity like that of the pure metal.
(iv) They acquire chemical inertness.
The stabilisation of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?
Chelation (formation of cycle by linkage between metal ion and ligand) stabilises the coordination compound. The ligand which chelates the metal ion are known as chelating ligand.
Here, only [Fe(C2O4)3]3− is a coordination compound which contains oxalate ion as a chelating ligand. Hence, it stabilises coordination compound by chelating Fe3+ ion.
The reagent which does not react with both, acetone and benzaldehyde?
(a) Sodium hydrogen sulphite
(b) Phenyl hydrazine
(c) Fehling's solution
(d) Grignard reagent
Acetone and benzaldehyde both do not react with Fehling's solution. Fehling's solution react with ketone as acetone is an ketone while benzaldehyde is an aromatic aldehyde having absence of α-hydrogen.
This practice paper will help students to practice new questions from the complete Chemistry syllabus. Students can revise the topics where they stuck while attempting this paper.