Are these practice questions for Some Basic Concepts Of Chemistry based on the CBSE pattern?

Yes. Every practice question is modeled on the CBSE Class 11 - Science Chemistry exam pattern — including MCQs, assertion-reason questions, and short-answer formats that frequently appear in CBSE papers.

Are the practice questions for Some Basic Concepts Of Chemistry free?

Yes. Every chapter includes free practice questions for Class 11 - Science students to get you started.

What types of questions are included?

The practice set for Some Basic Concepts Of Chemistry mainly includes MCQs and CBSE-style short-answer questions, with instant feedback on each answer. For full-length textbook practice, use the NCERT Solutions page.

Are the practice questions suitable for board exam preparation?

Yes. The questions test the same concepts and depth that CBSE asks in board exams. After finishing, also solve the NCERT and NCERT Exemplar exercises for Some Basic Concepts Of Chemistry for full coverage.

How many practice questions are there for Some Basic Concepts Of Chemistry?

The number scales with chapter length and concept density. Each chapter typically has 15-50 practice questions across MCQ and short-answer formats.

Some Basic Concepts Of Chemistry Class 11 Chemistry Practice Questions with Answers

easy

Propose a simple, physical method to distinguish between a homogeneous mixture (like a sugar solution) and a pure liquid compound (like water) without using any specialized laboratory equipment. Justify your proposed method.

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easy

Analyze the number 0.052090 and determine the number of significant figures.

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easy

The boiling point of ethanol is

78.37^\circ\text{C}

. Calculate this temperature in Kelvin.

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easy

Define molarity.

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easy

Define an empirical formula.

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easy

List the seven base physical quantities and their corresponding SI units.

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easy

Name the SI base unit for the amount of substance and its symbol.

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easy

Explain the difference between a homogeneous and a heterogeneous mixture with one example for each.

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easy

State the Law of Conservation of Mass.

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easy

Calculate the mass per cent of nitrogen, hydrogen, carbon, and oxygen in urea (

\text{CON}_2\text{H}_4

). (Atomic masses: C=12.01 u, O=16.00 u, N=14.01 u, H=1.008 u)

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medium

A student is tasked with determining the density of copper. The accepted literature value is

8.96 \text{ g/cm}^3

. The student records three measurements:

8.71 \text{ g/cm}^3

,

8.73 \text{ g/cm}^3

, and

8.72 \text{ g/cm}^3

. Evaluate these results in terms of precision and accuracy. Justify your conclusions with calculations.

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medium

Explain the terms 'precision' and 'accuracy' using an example.

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medium

Calculate the volume of

0.50

M hydrochloric acid (

\text{HCl}

) solution required to react completely with

10.0

g of calcium carbonate (

\text{CaCO}_3

) according to the equation:

\text{CaCO}_3(\text{s}) + 2\text{HCl}(\text{aq}) \rightarrow \text{CaCl}_2(\text{aq}) + \text{CO}_2(\text{g}) + \text{H}_2\text{O}(\text{l})

. (Molar mass of

\text{CaCO}_3 = 100.1

g/mol)

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medium

Justify why molality is often preferred over molarity as a unit of concentration for experiments that are conducted over a range of temperatures.

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medium

Describe the classification of matter at the macroscopic level. Use a flowchart to illustrate the classification into pure substances and mixtures, and their further subdivisions. Provide an example for each category.

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medium

Analyze the reaction for the combustion of propane:

\text{C}_3\text{H}_8(\text{g}) + 5\text{O}_2(\text{g}) \rightarrow 3\text{CO}_2(\text{g}) + 4\text{H}_2\text{O}(\text{l})

. Calculate the mass of water produced when

22

g of propane is burnt completely. (Molar mass of

\text{C}_3\text{H}_8 = 44

g/mol,

\text{H}_2\text{O} = 18

g/mol)

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medium

An unknown organic compound is found to contain only Carbon, Hydrogen, and Oxygen. Analysis reveals its composition to be

40.0\%

Carbon and

6.7\%

Hydrogen by mass. Formulate a clear, step-by-step plan to determine its empirical formula from this data. Justify each step.

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medium

A solution is prepared by dissolving

5.85

g of sodium chloride (

\text{NaCl}

) in enough water to make

200

mL of solution. Calculate the molarity of the solution. (Molar mass of NaCl =

58.5

g/mol)

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medium

A car's fuel efficiency is

32.0

miles per gallon. Apply dimensional analysis to convert this to kilometers per liter. (Given: 1 mile =

1.609

km, 1 gallon =

3.785

L)

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medium

Summarize three main postulates of Dalton's Atomic Theory.

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medium

An organic compound was found to contain

40.0\%

carbon,

6.7\%

hydrogen, and

53.3\%

oxygen by mass. Analyze this data to determine its empirical formula.

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medium

Apply scientific notation to express the number

543,000,000

with three significant figures.

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medium

Calculate the number of molecules in

0.25

moles of ammonia (

\text{NH}_3

).

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medium

Evaluate Dalton's postulate that "atoms are indivisible" in the context of both chemical and nuclear reactions. Justify its validity in each case.

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medium

Describe the three common scales used for measuring temperature and state the relationship between the Celsius and Kelvin scales.

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medium

You are tasked with preparing solutions of copper(II) sulfate for an experiment. (a) Design a step-by-step procedure to prepare

500.0 \text{ mL}

of a

2.00 \text{ M}

stock solution of

CuSO_4

using solid copper(II) sulfate pentahydrate,

CuSO_4 \cdot 5H_2O

. Your design must include the necessary mass calculation. (Molar masses: Cu=63.5, S=32.1, O=16.0, H=1.0 g/mol). (b) From this stock solution, formulate a method, including calculations, to prepare

250.0 \text{ mL}

of a

0.400 \text{ M}

CuSO_4

solution. Justify your calculation using the principle of mole conservation.

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medium

Critique the following procedure for preparing a

0.5 \text{ M}

solution of

NaOH

in a

250 \text{ mL}

volumetric flask: "Weigh approximately 5 g of

NaOH

pellets on a watch glass, transfer them to the volumetric flask, and then add water up to the mark." Propose at least two critical improvements and justify their necessity.

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medium

Explain the difference between mass and weight. Identify the SI unit for mass.

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medium

Design a laboratory experiment to verify the Law of Conservation of Mass using the precipitation reaction between aqueous solutions of lead(II) nitrate,

Pb(NO_3)_2

, and potassium iodide,

KI

. Your design must specify the apparatus, procedure, and the critical observation needed to validate the law.

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medium

A compound containing only carbon, hydrogen, and oxygen is analyzed. Combustion of a

1.50

g sample produces

2.20

g of

\text{CO}_2

and

0.90

g of

\text{H}_2\text{O}

. The molar mass of the compound is determined to be

60.0

g/mol. Examine the data to determine the empirical and molecular formulas of the compound.

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medium

Identify the number of significant figures in the number 0.05020.

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medium

Calculate the mass in grams of a single atom of gold (Au). (Atomic mass of Au =

197

u)

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hard

Explain the five rules for determining the number of significant figures in a measurement. Provide a clear example for each rule.

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hard

Design a complete experimental strategy to determine the molecular formula of a newly synthesized, unknown volatile liquid that is known to contain only carbon, hydrogen, and oxygen. Your strategy must outline three distinct experimental stages and justify the choice of method for each of the first two stages.

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hard

Define the terms atomic mass, average atomic mass, molecular mass, and formula mass. Explain how each is determined and provide an example for each.

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hard

Critique the statement: "An exact number, such as the '2' in the formula for water (

H_2O

), has an infinite number of significant figures." Justify whether this concept is always practically relevant in stoichiometric calculations.

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hard

Formulate a single unit factor (conversion factor) that can be used to convert a substance's density from units of

\text{g/cm}^3

to

\text{kg/m}^3

. Justify the components of your factor.

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hard

Summarize the five basic laws of chemical combination that govern the formation of compounds from elements. State each law clearly.

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hard

Boron has two stable isotopes,

^{10}\text{B}

and

^{11}\text{B}

. Their respective masses are

10.0129

u and

11.0093

u, and the average atomic mass of boron is

10.811

u. Calculate the natural abundance of each isotope.

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hard

In the synthesis of ammonia,

280

g of dinitrogen gas (

\text{N}_2

) is mixed with

90

g of dihydrogen gas (

\text{H}_2

). The reaction is:

\text{N}_2(\text{g}) + 3\text{H}_2(\text{g}) \rightarrow 2\text{NH}_3(\text{g})

. (a) Identify the limiting reagent. (b) Calculate the maximum mass of ammonia that can be produced. (c) Calculate the mass of the excess reagent that remains unreacted.

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hard

In an industrial reactor for the Haber process,

N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)

, a batch is prepared with

100.0 \text{ kg}

of dinitrogen (

N_2

) and

25.0 \text{ kg}

of dihydrogen (

H_2

). (a) Justify, with calculations, which reactant is the limiting reagent. (b) Propose a calculation to determine the maximum theoretical yield of ammonia (

NH_3

) in kilograms. (c) Evaluate the economic reasoning behind using one reactant in excess in a large-scale industrial process.

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hard

The density of a

2.05

M solution of acetic acid (

\text{CH}_3\text{COOH}

) in water is

1.02

g/mL. Calculate the molality of the solution. (Molar mass of

\text{CH}_3\text{COOH} = 60.05

g/mol)

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hard

Two compounds are formed between carbon and oxygen. Compound A contains

42.9\%

carbon by mass, while Compound B contains

27.3\%

carbon by mass. Formulate a proof to demonstrate that this data is consistent with the Law of Multiple Proportions.

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hard

Justify the international agreement in 1961 to use Carbon-12 as the standard for defining the atomic mass unit (amu). Propose one significant advantage and one potential disadvantage if the scientific community had decided to retain the lightest isotope, Hydrogen-1 (

^1H

), as the standard with a defined mass of exactly 1.

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hard

Critique the assertion that "Gay-Lussac's Law of Gaseous Volumes and Avogadro's Law are independent principles." Formulate a cohesive argument, using the reaction

H_2(g) + Cl_2(g) \rightarrow 2HCl(g)

as an example, to demonstrate how Avogadro's Law provides the necessary theoretical foundation to explain Gay-Lussac's empirical observations.

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Some Basic Concepts Of ChemistryClass 11 Chemistry Practice Questions