BASIC CONCEPTS chemistry MCQs

 

CHAPTER NO.1

BASIC CONCEPTS

 

Q1.      Select the most suitable answer from the given ones in each question.

(i)                                         The mass of one mole of electrons is

(a)              Properties which depend upon mass

(b)             Arrangement  of electrons in orbital

(c)              Chemical properties

(d)             The extent to which they may be affected in electromagnetic field (ii)        Which of the following statements is not true?

(a)                        isotopes with even atomic masses are comparatively abundant

(b)                       isotopes with odd atomic masses and even atomic number are comparatively abundant

(c)                        atomic masses are average masses of isotopes.

(d)                       Atomic masses are average masses of isotopes proportional to their relative abundance

(iii)                 Many elements have fractional atomic masses, this is because  

(a)                   The mass of the atom is itself fractional (b)         Atomic masses are average masses of isobars (c)          Atomic masses are average masses of isotopes.

(d)         Atomic masses are average masses of isotopes proportional to their relative abundance

(iv)                 The mass of one mole of electrons is

(a)                   008mg   (b)      0.55mg              (c)      0.184mg          (d)      1.673mg

(v)                    27g of Al will react completely with how much mass of O₂ to produce Al₂O₃

(a)     8g of oxygen                           (b)        16g of oxygen 

(c)     32g of oxygen                                     (d)        24g of oxygen

(vi)                               The number of moles of CO₂ which contain 8.0 g of oxygen.

(a)              0.25     (b)        0.50     (c)        1.0       (d)        1.50 

(vii)                            The largest number of molecules are present in

(a)              3.6g of H₂ O                (b)        4.8g of C₂H₅ OH

            (c)        2.8 g of CO                  (d)        5.4g of N₂O₅

(viii)                          One mole of SO₂ contains

(a)              6.02x10²³ atoms of oxygen

(b)             18.1x10²³ Molecules of SO₂

(c)              6.02x1023 atoms of sulphur 

(d)             4 gram atoms of SO₂

(ix)                               The volume occupied by 1.4 g of N₂at STP is  

(a)              2.24 dm3                             (b)        22.4dm3

(c)        1.12 dm³                      (d)        112 cm³

(x)                                 A limiting reactant is the one which  

(a)              is taken in lesser quantity in grams as compared to other reactants 

(b)             is taken in lesser quantity in volume as compared to the other reactants

(c)              give the maximum amount of the product which is required 

(d)             give the minimum amount of the product under consideration

Ans:     (i)a       (ii)d      (iii)d     (iv)b     (v)d      (vi)a     (vii)a    (viii)c