Chemistry Chapter 1 Entry Test MCQs
101. Which one act as a limiting reactant when 6g of carbon and 16 g of oxygen react to produce CO2
a. Anyone of oxygen and carbon
b. Carbon
c. Oxygen
d. None of these
102. For stoichiometry calculations, we have to assume
a. Side reaction occurs
b. Mass of reactants is less than the mass of products
c. Reaction is reversible
d. All the reactants are converted into products
103. If a sample of ammonium phosphate, (NH4)3PO4 contains 6 moles of hydrogen atoms. Then number of moles of oxygen atoms in the sample is
a. 4
b. 1
c. 6
d. 2
104. The law of conservation of mass and the law of definite proportions are obeyed while doing calculation of
a. Stoichiometry
b. Limiting reactant
c. Theoretical yield
d. All of these
105. 3NA, 2NA and 1NA molecules of N2, O2 and He are present in a container, the mole ratio of these gases is respectively
a. 2: 3: 1
b. 2: 1: 3
c. 3: 2: 1
d. 3: 1: 2
106. The sulphate of a certain metal has formula M2SO4.The formula of metal chloride would be
a. M2Cl2
b. MCl
c. MCl3
d. MCl2
107. Which of the following sets contains only compounds?
a. hydrogen, ammonia, oxygen
b. air, water, sodium
c. table salt, glucose, German silver
d. carbon monoxide, phosphine, phosgene
108. Total ions in 5 formula units of NaClO3 is equal to the number of
a. 8 protons in an oxygen atom
b. 10 electrons in neon
c. 2 isotopes of chlorine
d. 23 nucleons in sodium atom
109. Which one of the following pair is isoelectronic?
a. Na, K
b. Si, CO2
c. NH3, Mg
d. H2O, Ne
110. Mass of acetone is equal to the mass of
a. Propanal
b. Ethanal
c. 1-Butanol
d. Ethanol
111. Which of the following set of elements form nearly 50% of earth crust?
a. O, Mg, S, Fe, K
b. O, Mg, C, Ca, Fe
c. O , Mg , C , Si , Fe
d. O, Mg , Si , Ca , Fe
112. The number of OH- ions required to react completely with H+ ions produced by 100% dissociation of 49g H3PO4
a. 9.03 × 1023
b. 3.01 × 1023
c. 12.04 × 1023
d. 6.02 × 1023
113. The volume of NH3 obtained by the combination of 10 cm3 of N2 and 30 cm3 of H2 at S.T.P. is
a. 30 cm3
b. 20 cm3
c. 10 cm3
d. 40 cm3
114. Stoichiometric calculation assumes that
a. All the reactants are completely converted into product
b. In calculation law of conservation of mass and law of definite proportions are obeyed
c. No side reaction occurs
d. All of these
115. Which type of relationship can be studied with the help of balanced chemical equation
a. Mole – Mass relationship
b. Mass – mass relationship
c. All relations can be studied
d. Mass – volume relationship
116. “X” gram of calcium carbonate was completely burnt in air as. The weight of solid residue formed is 14g. What is value of “X” in grams
a. 100
b. 25
c. 200
d. 50
117. In the reaction 4NH3(g) + 5O2(g) 4NO(g) + 6H2O when one mole of ammonia and 1-mole of O2 are made to react to completion, then
a. All the ammonia will be consumed
b. 1.0 mol of H2O is produced
c. All the oxygen will be consumed
d. 1.0 mol of NO will be produced
118. The mass of water formed when 20g of H2 and 160g of oxygen react
a. 26g
b. 36g
c. 360g
d. 180g
119. When 0.1 kg of CaCO3 is decomposed the CO2 produced occupies a volume at STP
a. 22414 dm3
b. 2.2414 dm3
c. 224014 dm3
d. 22.414 dm3
120. If two moles of SO2 are oxidized to SO3, how many moles of oxygen molecules are required
a. 1
b. 0.5
c. 2
d. 1.5
121. In stoichiometry law of definite proportions is obeyed, it means that atoms are bound to
a. get oxidized
b. react
c. combine in any ratio
d. combine in definite ratios
122. When 1/2 mole of Hydrogen reacts with excess of chlorine what mass of HCl is likely to form
a. 73 g
b. 39 g
c. 36.5g
d. 23 g
123. Theoretical yield is calculated by
a. balanced chemical equation
b. moles of products
c. experiment
d. rate of reaction
124. N2 + O2 → 2NO. What volume of NO will be produced by 10dm3 each of N2 and O2 reacted together?
a. 40cm3
b. 20dm3
c. 10cm3
d. 30cm3
125. 𝐒𝐢𝐎𝟐+𝟑𝐂→𝐒𝐢𝐂+𝟐𝐂𝐎 The mass of SiC produced when 1.5 mole of carbon reacts with excess of sand will be
a. 13.3g
b. 40g
c. 26g
d. 20g
126. Ratio of theoretical yield and actual yield is
a. Always one
b. Always zero
c. Always less than 1
d. Always greater than 1
127. NaNO3 → NaNO2 + O2 170g of NaNO3 upon decomposition give 48g O2, the % age yield is
a. 88%
b. 50%
c. 95%
d. 75%
128. A limiting reactant can determine _
a. Amount of product
b. Rate of reaction
c. Actual yield
d. Order of reaction
129. 6.02 x 1022 H+ ions are produced by the ionization of
a. 7.3g HCl
b. 3.65g HCl
c. 36.5g HCl
d. 36g HCl
130. One of the purposes to use limiting reactant in a reaction is to
a. slow down the reaction
b. Oxidise the other reactant
c. decrease the activation energy
d. completely consume expensive reactant
131. Mechanical loss while doing practical work in laboratory
a. helps identify limiting reactant
b. causes reaction to stop
c. decreases actual yield
d. completes the reaction
132. Occurrence of side reactions tend to:
a. stop the reaction
b. Fasten the reaction
c. consume limiting reactant
d. disturb actual yield
133. How many moles of oxygen gas are needed to prepare 44.8dm3 of Carbon monoxide when Carbon is combusted in excess of oxygen
a. 3
b. 4
c. 1
d. 2
134. Which of the following percentage yield shows maximum efficiency of reaction?
a. 95%
b. 90%
c. 50%
d. 70%
135. Stoichiometry does not give the idea of
a. Reactant – product relation
b. mass-mass relation
c. Mole – volume relation
d. Limiting reactant
136. H2SO4 ionizes in water according to the following equation H2SO4→2H+ + SO-24 98g of H2SO4 constitute its
a. 1g ion
b. 1g atom
c. 1g formula
d. 1g molecule