Basic Concepts Of Chemistry Test

Basic Concepts Of Chemistry

This is Basic concepts of chemistry Test-01 for CBSE class 12 Chemistry.. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Chemistry does not play a major role in
  • A
    Explaining ozone depletion
  • B
    Explaining superconductivity
    Correct
  • C
    Design and synthesis new materials having specific magnetic, electric and optical properties.
  • D
    Large scale production of a variety of fertilizers
2
Matter can be classified at the macroscopic or bulk level as
  • A
    mixtures or pure substances
    Correct
  • B
    solids and liquids
  • C
    Atoms and molecules
  • D
    Elements and molecules
3
In a homogeneous mixture,
  • A
    the components completely mix with each other and its composition is not uniform throughout
  • B
    the components do not mix with each other and its composition is not uniform throughout
  • C
    the components completely mix with each other and its composition is uniform throughout.
    Correct
  • D
    The components do not mix with each other and its composition is uniform throughout.
4
Which of the following statements about pure substances correct?
  • A
    Pure substances have fixed composition, whereas mixtures may contain the components in fixed ratio and their composition is fixed.
  • B
    Pure substances have fixed composition, whereas mixtures may contain the components in any ratio and their composition is variable.
    Correct
  • C
    Pure substances have variable composition, whereas mixtures may contain the components in any ratio and their composition is variable.
  • D
    Pure substances do not have fixed composition, whereas mixtures may contain the components in any fixed ratio
5
Particles of compounds are
  • A
    molecules of two or more atoms of different elements
    Correct
  • B
    homogeneous mixtures
  • C
    atoms
  • D
    heterogeneous mixtures
6
Physical properties are those properties which ______ measured or observed ______ changing the identity or the composition of the substance
  • A
    cannot be ,even by
  • B
    can be, after
  • C
    cannot be ,without
  • D
    can be ,without
    Correct
7
SI units for Base Physical Quantities of length, mass and current are
  • A
    meter, kilogram, ampere
    Correct
  • B
    meter, kilogram, candela
  • C
    meter, gram, ampere
  • D
    decimetre, kilogram, ampere
8
SI unit of density is
  • A
    kg $m^{-2}$
  • B
    kg $m^3$
  • C
    kg $m^{-3}$
    Correct
  • D
    kg$^{-1} m^3$
9
The kelvin scale is related to celsius scale by
  • A
    K = °C + 273.15
    Correct
  • B
    K = °C + 32
  • C
    K = °C + 212
  • D
    K = °C + 100
10
In scientific notation for such numbers, any number can be represented in the form N × 10n where
  • A
    n is an exponent having positive or negative values and N can vary from 10 to 100
  • B
    n is an exponent having positive or negative values and N can vary from 1 to 10
    Correct
  • C
    n is an exponent having positive or negative values and N can vary from 0 to 1
  • D
    n is an exponent having positive values only and N can vary from 1 to 10
11
Precision and Accuracy refer to _______ of various measurements for the same quantity(repeatability) and agreement of a particular value to the_______ of the result.
  • A
    minimum , true value
  • B
    maximum , true value
  • C
    closeness , other values
  • D
    closeness , true value
    Correct
12
Significant figures are
  • A
    meaningful digits which are known with certainty
    Correct
  • B
    digits before the decimal point
  • C
    first three digits after the decimal point
  • D
    digits after the decimal point
13
According to Gay Lussac’s Law of Gaseous Volumes when gases combine or are produced in a chemical reaction they do so ______ when gases combine or are produced in a chemical reaction they do so by volume provided all gases are at same temperature and pressure.
  • A
    in a ratio of 1:2
  • B
    in inverse ratio
  • C
    in a simple ratio
    Correct
  • D
    in a ratio of 1:1
14
According to Avogadro Law equal volumes of gases at the same temperature and pressure should contain
  • A
    same type of molecules
  • B
    different types of molecules
  • C
    unequal number of molecules
  • D
    equal number of molecules
    Correct
15
Molecular mass is the
  • A
    average of atomic masses of the elements present in a molecule
  • B
    minimum of atomic masses of the elements present in a molecule
  • C
    sum of atomic masses of the elements present in a molecule
    Correct
  • D
    maximum of atomic masses of the elements present in a molecule