Chemistry Chapter 1 Entry Test MCQs
76. Which of the following will weigh more?
a. 2 x 1023 atoms of C
b. 10g Fe STP
c. 11.2 dm3 of O2 at
d. 1.6 g atom of N
77. 2.24 dm3 of CO2 gas at S.T.P has mass
a. 44g
b. 28g
c. 4.4g
d. 2.8g
78. Block of metals Mg, Al, Fe, Zn of each mass 100g. The maximum number of atoms are present in a block of metal.
a. Zn
b. Mg
c. Fe
d. Al
Empirical and Molecular formula
79. Which of the following term is not used for ionic compounds?
a. Molecular formula
b. Formula unit
c. Formula Mass
d. Empirical formula
80. Polymeric molecules are best represented by
a. empirical formula
b. formula unit
c. molecular formula
d. linear structure
81. Which of the following is an empirical formula?
a. C3H8
b. C2H2
c. C4H10
d. C2H4
82. If the only representation of a compound is its empirical formula, it means that
a. Molecular mass is different from empirical formula mass
b. M.F is different from E.F
c. The compound has the same M.F and E.F
d. The compound is ionic
83. Which information can be deduced from the empirical formula of a compound
a. the way atoms have combined
b. the polarity of molecule
c. the activation energy of reaction
d. the simplest ratio between atoms
84. For which compound you find the same empirical and molecular formula?
a. ammonia
b. water
c. methane
d. all of these
85. Giant covalent molecules are best represented by
a. empirical formula
b. formula unit
c. molecular formula
d. linear structure
86. A compound with empirical formula CHO2 and molecular mass 90g / mole. The molecular formula of a compound is
a. C12H22O11
b. C6H12O6
c. HCOOH
d. (COOH)2
87. Elemental analysis is performed to determine
a. Structural formula of a compound
b. Molar mass of the compound
c. Mass of halogen present in a compound
d. Empirical formula of a compound
88. CH2O is the empirical formula of
a. CH3. CH(OH). COOH
b. C12H22O11
c. CH3CHO
d. CH2(OH)CH2(OH)
89. An unknown compound has empirical formula CH3O. Its molar mass is 62g/mole. The compound may be (write formulas)
a. CH2(OH)CH2(OH)
b. C2H5OH
c. CH2(OH)CH(OH)CH2(OH)
d. CH3COOH3
90. While determine molecular formula, the simple multiple ‘n’ is not unity for
a. C12H22O11
b. H2O
c. CO2
d. H2O2
91. A compound contains 50% S and 50% O by mass. The empirical formula of compound is
a. SO3
b. SO2
c. SO
d. S2O3
92. Which one of the following statements is not involved in the determination of empirical formula?
a. gram atom of each element
b. %age of each element
c. atomic ratio of element
d. isotopes of each element
93. A pair of compounds that has same empirical formula
a. Acetic acid and glucose
b. Acetic acid and formic acid
c. Formic acid and sucrose
d. Both a and b
94. There are different steps in determining the empirical formula
Step I. Calculating the number of gram atom
Step II. Determining the atomic ratio
Step III. Determining the percentage composition
What is the correct sequence of the above steps?
a. II, I, III
b. I, II, III
c. III, I, II
d. III, II, I
95. The value of ‘n’ in determining molecular formula is obtained from the relation
a. n= Empirical mass molecualr mass
b. n = mass molar mass
c. Cannot be determined
d. n= Conc. × Volume
96. The simplest formula of a compound containing 50% of element X (At.wt = 10) and 50% of element Y (At. wt = 20) is
a. X2Y
b. XY
c. X2Y3
d. XY2
97. Which one will produce largest number of negatively charged ions in case of 100% dissociation of 1 mole
a. NaOH
b. FeCl3
c. ZnCl2
d. Na2SO4
98. Efficiency of a chemical reaction is
a. Percentage yield
b. Actual yield
c. Theoretical yield
d. All of these
Stoichiometry
99. 0.36 moles of Aluminum and oxygen each react to produce alumina then which of the following is limiting reactant and non-limiting reactant respectively
a. Al, Al2O3
b. Al, O2
c. O2, Al2O3
d. O2, Al
100. One of the following is not the limitation of balanced chemical equation
a. Rate of reaction
b. Conditions of reaction
c. Moles of reactants and products
d. Physical states of reactants