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JEE • CHEMISTRY • SOME BASIC CONCEPTS OF CHEMISTRY
Some basic concepts of chemistry practice · Mixed difficulty
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Practice format and chapter quiz
These sets use single-correct-answer MCQs. They do not cover every JEE Main or JEE Advanced question format and are not full-length mock papers.
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Showing 181-210 of 436 questions
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181
Medium
181 of 436
Application
+4 | -1
If a piece of copper weighs , how many atoms does it contain?
View answer and explanation
Correct option: A
Option A () is correct because it is calculated by dividing the given mass by the molar mass and multiplying by Avogadro's number.
182
Easy
182 of 436
Application
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Four faradays of electricity is passed through a solution of . The mass of copper deposited at the cathode is: (At. mass of ).
View answer and explanation
Correct option: C
Option C () is correct because it represents the mass of copper deposited when four faradays of electricity are passed through a solution.
183
Medium
183 of 436
Application
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An element reacts with hydrogen leading to formation of a class of compounds that is analogous to hydrocarbons. of forms of a mixture of two compounds of and in the molar ratio of Determine the molar mass of
View answer and explanation
Correct option: A
28
Option A (28) is correct because applying the Principle of Atomic Conservation (POAC) on element X allows us to determine its molar mass.
184
Medium
184 of 436
Application
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Rest mass of 1 mole neutrons is:
View answer and explanation
Correct option: D
Option D () is correct because it is the product of the mass of one neutron and Avogadro's number.
185
Medium
185 of 436
Application
+4 | -1
Number of moles of hydrogen atoms present in of acetic acid:
View answer and explanation
Correct option: A
Option A () is correct because one molecule of acetic acid contains 4 hydrogen atoms, and we are dealing with one molecule (60 amu).
186
Easy
186 of 436
Application
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Vapour density of a volatile substance is . Its molecular weight would be:
View answer and explanation
Correct option: C
64
Option C (64) is correct because the molecular weight is twice the vapor density, and the vapor density is given relative to methane (CH4 = 1).
187
Medium
187 of 436
Application
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moles of and moles of react together to form solid . Calculate the amount of formed .
View answer and explanation
Correct option: B
Option B () is correct because it is the mass of Ag₂CrO₄ formed, calculated using the limiting reagent concept.
188
Easy
188 of 436
Remembering
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Molarity is expressed as:
View answer and explanation
Correct option: B
Option B () is correct because molarity is defined as moles of solute per liter of solution.
189
Medium
189 of 436
Application
+4 | -1
Number of molecules in 1 litre of oxygen at NTP is:
View answer and explanation
Correct option: B
Option B is correct because at NTP, 1 mole of any gas occupies 22.4 L, so the number of molecules in 1 L is Avogadro's number divided by 22.4.
190
Medium
190 of 436
Analyzing
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of is added to of . The resultant solution becomes:
View answer and explanation
Correct option: C
acidic
Option C (acidic) is correct. The number of moles of HCl is greater than the number of moles of NaOH, resulting in an acidic solution.
191
Medium
191 of 436
Understanding
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Statement I: The molality of the solution does not change with temperature.
Statement II: The molality is expressed in the unit of of solvent.
Statement II: The molality is expressed in the unit of of solvent.
View answer and explanation
Correct option: B
Statement I is true; Statement II is true Statement II is not the correct explanation of Statement I
Option B (Statement I is true; Statement II is true Statement II is not the correct explanation of Statement I) is correct because molality is defined as moles of solute per kg of solvent, which is mass-based and thus independent of temperature, but this definition doesn't explain the temperature independence.
192
Hard
192 of 436
Application
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For the reaction: mole of and excess of will produce
View answer and explanation
Correct option: B
4 mole of C
Option B (4 mole of C) is correct because according to the stoichiometry of the reaction, 2 moles of A produce 1 mole of C, so 8 moles of A will produce 4 moles of C.
193
Medium
193 of 436
Application
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The number of moles of water present in a spherical water droplet of radius is
[Given: density of water in the droplet
[Given: density of water in the droplet
View answer and explanation
Correct option: B
Option B (2π/27) is correct because the number of moles of water is calculated from the volume of the sphere, density of water, and molar mass of water.
194
Medium
194 of 436
Analyzing
+4 | -1
The equivalent weight of in the reaction, would be
View answer and explanation
Correct option: B
Option B (M) is correct because the n-factor for Fe3O4 in the given reaction is 1, so the equivalent weight is M/1 = M.
195
Medium
195 of 436
Application
+4 | -1
Molarity and molality of a solution of an liquid (mol. wt. ) in aqueous solution is 9 and 10 respectively. What is the density of solution?
View answer and explanation
Correct option: D
Option D (1.35 g/cc) is correct because the density is calculated using the molarity, molality, and molecular weight of the solute.
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196
Easy
196 of 436
Application
+4 | -1
The number of oxygen atoms in of is (molar mass of )
View answer and explanation
Correct option: C
The correct answer is because the number of oxygen atoms is calculated from the moles of the compound and the number of oxygen atoms per molecule.
197
Easy
197 of 436
Application
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Active mass of in 10 lit vessel is
View answer and explanation
Correct option: B
Option B ( M) is correct because the active mass is calculated by dividing the number of moles by the volume in liters.
198
Hard
198 of 436
Application
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A 0.50 solution of reacts with excess of and solutions according to the equation, . Which of the following statements is true?
View answer and explanation
Correct option: C
0.5 litre of the solution produces 0.15 mole of
Option C (0.5 litre of the solution produces 0.15 mole of ) is correct because 5 moles of produces 3 moles of .
199
Medium
199 of 436
Application
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The percentage weight of in white vitriol is approximately equal to
View answer and explanation
Correct option: D
Option D () is correct because it is calculated by dividing the mass of Zn by the molecular weight of the compound and multiplying by 100.
200
Medium
200 of 436
Analyzing
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Statement I: The number of atoms in a given mass of dioxygen (oxygen) and trioxygen (ozone) gases is same.
Statement II: The number of atoms depends on atomic mass, not on molecular mass.
Statement II: The number of atoms depends on atomic mass, not on molecular mass.
View answer and explanation
Correct option: A
If both statements are CORRECT, and Statement II is the CORRECT explanation of Statement I
If both statements are CORRECT, and Statement II is the CORRECT explanation of Statement I. Same mass, same element and hence, same number of atoms.
201
Medium
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Application
+4 | -1
On analysis a certain compound was found to contain iodine and oxygen in the ration 254 g of iodine and 80 g of oxygen. The atomic mass of iodine is 127 and that of oxygen is 16. Which is the formula of the compound?
View answer and explanation
Correct option: D
Option D () is correct because the ratio of iodine to oxygen atoms is 2:5 after converting masses to moles.
202
Medium
202 of 436
Analyzing
+4 | -1
For the reaction: . The equivalent mass of is (M is the mol wt of )
View answer and explanation
Correct option: D
Option D () is correct because the n-factor for the given reaction is 20, and the equivalent mass is calculated as M/n.
203
Hard
203 of 436
Analyzing
+4 | -1
In the reaction,
View answer and explanation
Correct option: D
at STP is produced for every mole HCl(aq) consumed
The correct answer is D because the stoichiometry of the balanced equation shows that 6 moles of HCl produce 3 moles of H2, meaning 1 mole of HCl produces 0.5 moles of H2, which is 11.2 L at STP.
204
Medium
204 of 436
Application
+4 | -1
Consider the following reaction
If 4 mole of mole of mole of reacts with 6 mole of , then the limiting reagent is
If 4 mole of mole of mole of reacts with 6 mole of , then the limiting reagent is
View answer and explanation
Correct option: C
Option C (C) is correct because C is the limiting reagent as it is completely consumed before the other reactants.
205
Medium
205 of 436
Analyzing
+4 | -1
In the following
Equivalent weight of (Molecular weight M) is
Equivalent weight of (Molecular weight M) is
View answer and explanation
Correct option: D
Option D () is correct because the equivalent weight is the molecular weight divided by the total number of electrons transferred in the redox reaction.
206
Medium
206 of 436
Application
+4 | -1
2 mole of ethyl alcohol are present with 6 mole of water. The mole fraction of alcohol is:
View answer and explanation
Correct option: D
0.25
Option D (0.25) is correct because the mole fraction is calculated by dividing the moles of alcohol by the total moles of the solution.
207
Medium
207 of 436
Application
+4 | -1
If the density of water is 1 g ) then the volume occupied by one molecule of water is approximately
View answer and explanation
Correct option: D
Option D () is correct because it is the approximate volume calculated by dividing the molar volume by Avogadro's number.
208
Medium
208 of 436
Application
+4 | -1
0.1 mole of a carbohydrate with empirical formula contains 1 g of hydrogen. What is its molecular formula?
View answer and explanation
Correct option: A
Option A () is correct because the molecular formula is determined by finding the number of moles of hydrogen and relating it to the empirical formula.
209
Hard
209 of 436
Analyzing
+4 | -1
One mole of mixture of and has a mean molar mass of On heating to a temperature, at which all the is dissociated into the mean molar mass tends to a lower value of What is the mole ratio of and in the original mixture?
View answer and explanation
Correct option: A
Option A (5: 1: 4) is correct because solving the system of equations derived from the given molar mass data yields the mole ratio of N2, NO2, and N2O4 as 5:1:4.
210
Hard
210 of 436
Application
+4 | -1
What will be the minimum molar mass of a compound containing of nickel?
View answer and explanation
Correct option: B
15 kg
Option B (15 kg) is correct because it is calculated by assuming the compound contains at least one nickel atom and then determining the molar mass based on the given percentage.
Revision notes and key takeaways
Review SOME BASIC CONCEPTS OF CHEMISTRY in your textbook or class notes, then use this set to check your understanding.
Showing 181-210 of 436 questions
