Stoichiometry and Chemical Bonding Practice Problems

Chemical Bonding and Atomic Properties

1) In the compound NaCl:
I. A pair of atoms share their electronic link (F)
II. Sodium presents the electronic configuration of Neon (V)
III. Chlorine presents the electronic configuration of Argon (V)

2) In the compound MgCl₂, we can say that magnesium:
I. Has an octet in its valence shell (V)
II. Lost 2 electrons (V)
III. Gained 2 electrons (F)
IV. Shares its valence electrons (F)

4) Given the compounds PCl₅, BF₃, CH₄, and XeF₄, it is possible to say:
I. Carbon (C) satisfies the octet rule (V)
II. The compound BF₃ has 26 total valence electrons (F)
III. P and Xe have 5 and 8 valence electrons, respectively (V)

Stoichiometry and Chemical Reactions

6) One of the main reactions in the metallurgy of Iron (Fe) is as follows:
Fe₂O₃(s) + 3 CO (g) → 2 Fe + 3 CO₂(g). If one ton of Fe₂O₃ produces 400 kg of Iron (Fe), and we assume the reaction occurs with 100% yield, we can say the ore purity is:

7) Given the following reaction:
CaCl₂ + 2 HNO₃ → Ca(NO₃)₂ + 2 HCl. How much calcium nitrate is obtained when mixed:

8) From the unbalanced equation KClO₃ → KCl + O₂, determine the mass of KClO₃ that is required to obtain 100 g of molecular oxygen:

9) 20 g of Bismuth(III) oxide reacted with 50 g of nitric acid according to the following balanced reaction:
Bi₂O₃ + 6 HNO₃ → 2 Bi(NO₃)₃ + 3 H₂O. The mass of Bi(NO₃)₃ formed and the limiting reagent, respectively, are:

10) Given the following unbalanced reaction:
Cu + I₂ → CuI. For one mole of Cu:

11) Given the following unbalanced reaction:
Ca(HCO₃)₂ → CaO + H₂O + CO₂. If 40.5 g of calcium bicarbonate is heated, we can confirm that:

12) 122.8 g of MnO₂ (85% purity) reacted with excess HCl to form molecular chlorine (Cl₂) according to the following reaction:
MnO₂ + 4 HCl → MnCl₂ + Cl₂ + 2 H₂O. The mass in grams of molecular chlorine formed is:

13) The synthesis of aspirin is produced from salicylic acid and acetic anhydride by the following reaction:
C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + CH₃COOH. Determine the yield of the reaction if 21 g of the compound is obtained from 20 g of salicylic acid.

14) Ethyl alcohol burns according to the following equation:
C₂H₅OH + 3 O₂ → 2 CO₂ + 3 H₂O. When 1.5 mol of ethanol burns in the presence of 2 moles of oxygen, the number of moles of water produced is:

Mass Composition and Empirical Formulas

15) 15 g of Carbon (C) reacted with 15 g of Oxygen (O). When the reaction ends, there is a remnant of 0.75 g of C. According to the above, we can conclude that the mass of the compound formed is:

16) The mass ratio of elements A and B is 1.5. In accordance with the above, the mass of compound AB that can be obtained by reacting 18 grams of A with 30 grams of B will be:

17) An unknown compound has 39% S, 58.5% O, and the remainder is H. Its empirical formula will be:

18)
19)
20)
21)
22)
23)
24)