Q. In the reaction 2H2 + O2 → 2H2O, what is the ratio of moles of hydrogen to moles of oxygen?
A.
1:1
B.
2:1
C.
2:2
D.
1:2
Show solution
Solution
The balanced equation shows that 2 moles of H2 react with 1 mole of O2, giving a ratio of 2:1.
Correct Answer:
B
— 2:1
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Q. In the reaction 2H2 + O2 → 2H2O, which element is oxidized?
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Solution
Oxygen (O) is oxidized as it goes from 0 in O2 to -2 in H2O.
Correct Answer:
B
— O
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Q. In the reaction 2Na + Cl2 → 2NaCl, how many grams of NaCl can be produced from 5 g of Na?
A.
10 g
B.
15 g
C.
20 g
D.
25 g
Show solution
Solution
5 g of Na = 0.217 moles. 2 moles of Na produce 2 moles of NaCl, so 0.217 moles of NaCl = 0.217 * 58.5 g = 12.7 g.
Correct Answer:
A
— 10 g
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Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens if SO2 is removed from the system?
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase in temperature
Show solution
Solution
Removing SO2 will shift the equilibrium to the left to produce more SO2, according to Le Chatelier's principle.
Correct Answer:
B
— Shift to the left
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Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens to the equilibrium if the volume of the container is decreased?
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase the rate of reaction
Show solution
Solution
Decreasing the volume increases the pressure, and the equilibrium will shift towards the side with fewer moles of gas, which is the right side (2 moles of SO3).
Correct Answer:
A
— Shift to the right
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Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what is the effect of increasing the pressure on the equilibrium?
A.
Shift to the left
B.
Shift to the right
C.
No effect
D.
Depends on the temperature
Show solution
Solution
Increasing the pressure will shift the equilibrium towards the side with fewer moles of gas, which is the right side in this case (2 moles of SO3).
Correct Answer:
B
— Shift to the right
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Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what is the effect of increasing the concentration of SO2?
A.
Shifts to the right
B.
Shifts to the left
C.
No effect
D.
Increases the rate of reaction
Show solution
Solution
Increasing the concentration of a reactant shifts the equilibrium position to the right, favoring the formation of products (SO3).
Correct Answer:
A
— Shifts to the right
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Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what will happen if SO3 is removed from the system?
A.
Equilibrium shifts to the left
B.
Equilibrium shifts to the right
C.
No change
D.
Equilibrium constant increases
Show solution
Solution
Removing SO3 will shift the equilibrium to the right to produce more SO3, according to Le Chatelier's principle.
Correct Answer:
B
— Equilibrium shifts to the right
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Q. In the reaction 3A + 2B → 4C, if 6 moles of A are used, how many moles of C will be produced?
A.
4 moles
B.
6 moles
C.
8 moles
D.
12 moles
Show solution
Solution
From the stoichiometry, 3 moles of A produce 4 moles of C. Therefore, 6 moles of A will produce (6 moles A) x (4 moles C / 3 moles A) = 8 moles of C.
Correct Answer:
C
— 8 moles
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Q. In the reaction 3H2 + N2 → 2NH3, how many moles of nitrogen are required to produce 6 moles of ammonia?
A.
3 moles
B.
2 moles
C.
1 mole
D.
4 moles
Show solution
Solution
According to the stoichiometry, 2 moles of NH3 require 1 mole of N2. Therefore, 6 moles of NH3 will require 3 moles of N2.
Correct Answer:
A
— 3 moles
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Q. In the reaction 3H2 + N2 → 2NH3, which element is oxidized?
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Solution
Hydrogen (H) is oxidized as it goes from an oxidation state of 0 to +1 in NH3.
Correct Answer:
A
— H
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Q. In the reaction 4Al + 3O2 → 2Al2O3, how many moles of Al2O3 are produced from 12 moles of Al?
A.
2 moles
B.
3 moles
C.
6 moles
D.
8 moles
Show solution
Solution
According to the stoichiometry, 4 moles of Al produce 2 moles of Al2O3. Therefore, 12 moles of Al will produce (12/4) x 2 = 6 moles of Al2O3.
Correct Answer:
C
— 6 moles
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Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many grams of Fe2O3 can be produced from 8 grams of Fe?
A.
16 g
B.
32 g
C.
48 g
D.
24 g
Show solution
Solution
8 g of Fe = 0.143 moles. 4 moles of Fe produce 2 moles of Fe2O3, so 0.0715 moles of Fe2O3 = 0.0715 * 160 g = 11.44 g.
Correct Answer:
C
— 48 g
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Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe are required to react with 6 moles of O2?
A.
4 moles
B.
6 moles
C.
8 moles
D.
12 moles
Show solution
Solution
From the balanced equation, 3 moles of O2 react with 4 moles of Fe. Therefore, 6 moles of O2 will require (4/3) * 6 = 8 moles of Fe.
Correct Answer:
C
— 8 moles
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Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe2O3 are produced from 12 moles of Fe?
A.
2 moles
B.
3 moles
C.
4 moles
D.
6 moles
Show solution
Solution
From the balanced equation, 4 moles of Fe produce 2 moles of Fe2O3. Therefore, 12 moles of Fe will produce (12/4) x 2 = 6 moles of Fe2O3.
Correct Answer:
C
— 4 moles
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Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe2O3 can be produced from 8 moles of Fe?
A.
2 moles
B.
4 moles
C.
6 moles
D.
8 moles
Show solution
Solution
From the balanced equation, 4 moles of Fe produce 2 moles of Fe2O3. Therefore, 8 moles of Fe will produce 4 moles of Fe2O3.
Correct Answer:
B
— 4 moles
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Q. In the reaction 4Fe + 3O2 → 2Fe2O3, how many moles of Fe2O3 can be produced from 12 moles of Fe?
A.
3 moles
B.
6 moles
C.
9 moles
D.
12 moles
Show solution
Solution
From the stoichiometry, 4 moles of Fe produce 2 moles of Fe2O3. Therefore, 12 moles of Fe will produce (12/4) x 2 = 6 moles of Fe2O3.
Correct Answer:
B
— 6 moles
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Q. In the reaction 4Fe + 3O2 → 2Fe2O3, what is the oxidation state of iron in Fe2O3?
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Solution
In Fe2O3, iron has an oxidation state of +3.
Correct Answer:
B
— +3
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Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), if the pressure is increased, which direction will the equilibrium shift?
A.
To the left
B.
To the right
C.
No shift
D.
Depends on temperature
Show solution
Solution
Increasing pressure shifts the equilibrium towards the side with fewer moles of gas, which is the right side in this case.
Correct Answer:
B
— To the right
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Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), if the temperature is decreased, what will happen to the equilibrium?
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase in pressure
Show solution
Solution
Decreasing the temperature for an exothermic reaction will shift the equilibrium to the right, favoring the formation of CH3OH.
Correct Answer:
A
— Shift to the right
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Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what will happen if H2 is removed from the system at equilibrium?
A.
Equilibrium shifts to the right
B.
Equilibrium shifts to the left
C.
No change
D.
Equilibrium constant increases
Show solution
Solution
Removing H2 will shift the equilibrium to the left to produce more H2, thus favoring the reactants.
Correct Answer:
B
— Equilibrium shifts to the left
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Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what will happen if H2 is removed from the system?
A.
Shift to the left
B.
Shift to the right
C.
No change
D.
Increase the rate of reaction
Show solution
Solution
Removing H2 will shift the equilibrium to the left to produce more H2, according to Le Chatelier's principle.
Correct Answer:
A
— Shift to the left
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Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what will happen if H2 is removed?
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Equilibrium constant increases
Show solution
Solution
Removing H2 will shift the equilibrium to the left to produce more H2, according to Le Chatelier's principle.
Correct Answer:
B
— Shift to the left
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Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what will happen if the volume of the container is decreased?
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase in temperature
Show solution
Solution
Decreasing the volume increases the pressure, which shifts the equilibrium to the side with fewer moles of gas, favoring the production of CH3OH.
Correct Answer:
A
— Shift to the right
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Q. In the reaction Zn + CuSO4 → ZnSO4 + Cu, which element is oxidized?
A.
Zn
B.
Cu
C.
SO4
D.
None of the above
Show solution
Solution
Zinc (Zn) is oxidized as it loses electrons to form Zn2+.
Correct Answer:
A
— Zn
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Q. In the reaction: 2A(g) ⇌ B(g) + C(g), if the volume of the container is decreased, what will happen?
A.
Shift to the left
B.
Shift to the right
C.
No change
D.
Depends on the temperature
Show solution
Solution
Decreasing the volume increases the pressure, and the equilibrium will shift towards the side with fewer moles of gas, which is the left side in this case.
Correct Answer:
A
— Shift to the left
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Q. In the reaction: 2A(g) ⇌ B(g) + C(g), if the volume of the container is decreased, what will happen to the equilibrium?
A.
Shift to the left
B.
Shift to the right
C.
No change
D.
Depends on temperature
Show solution
Solution
Decreasing the volume increases the pressure, and the equilibrium will shift to the side with fewer moles of gas, which is the left side in this case.
Correct Answer:
A
— Shift to the left
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Q. In the reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens if the temperature is increased?
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase in Kp
Show solution
Solution
If the reaction is exothermic, increasing the temperature will shift the equilibrium to the left, favoring the reactants.
Correct Answer:
B
— Shift to the left
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Q. In the redox reaction 2Fe2O3 + 3C → 4Fe + 3CO2, what is the oxidation state of carbon in CO2?
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Solution
In CO2, the oxidation state of carbon is +4.
Correct Answer:
C
— +4
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Q. In the van der Waals equation, what do the constants 'a' and 'b' represent?
A.
Pressure and volume
B.
Attraction and volume
C.
Temperature and pressure
D.
Volume and temperature
Show solution
Solution
'a' accounts for the attractive forces between molecules, while 'b' accounts for the volume occupied by the gas molecules.
Correct Answer:
B
— Attraction and volume
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Showing 391 to 420 of 2802 (94 Pages)
Chemistry Syllabus (JEE Main) MCQ & Objective Questions
The Chemistry Syllabus for JEE Main is crucial for students aiming to excel in their exams. Understanding this syllabus not only helps in grasping fundamental concepts but also enhances performance in objective questions and MCQs. Regular practice with these types of questions is essential for scoring better and mastering important topics.
What You Will Practise Here
Basic Concepts of Chemistry
Atomic Structure and Chemical Bonding
States of Matter: Gases and Liquids
Thermodynamics and Thermochemistry
Equilibrium: Chemical and Ionic
Redox Reactions and Electrochemistry
Hydrocarbons and Environmental Chemistry
Exam Relevance
The Chemistry syllabus is a significant part of CBSE, State Boards, NEET, and JEE exams. Questions from this syllabus often appear in various formats, including multiple-choice questions, assertion-reason type questions, and numerical problems. Familiarity with the common question patterns can greatly enhance your exam preparation and confidence.
Common Mistakes Students Make
Misunderstanding the periodic trends and their implications.
Confusing different types of chemical bonds and their properties.
Neglecting to balance redox reactions properly.
Overlooking the significance of units in thermodynamic calculations.
Failing to apply concepts of equilibrium in problem-solving.
FAQs
Question: What are the key topics I should focus on in the Chemistry syllabus for JEE Main?Answer: Focus on atomic structure, chemical bonding, thermodynamics, and equilibrium as they are frequently tested.
Question: How can I improve my performance in Chemistry MCQs?Answer: Regular practice with past papers and understanding concepts deeply will help you tackle MCQs effectively.
Start your journey towards mastering the Chemistry Syllabus (JEE Main) by solving practice MCQs today. Test your understanding and build confidence for your exams!
