Chemistry Review Manual 2
Chemistry Review Manual 2 Chemistry Review Manual 2
(c) carbon dioxide and carbon tetrachloride, CCl 4 (d) lithium bromide, LiBr, and water (e) sodium nitrate, NaNO 3 , and carbon tetrachloride, CCl 4 4.3 Electrolytes can be strong or weak. For example, most acids are molecules that dissociate in water. They react with water to form an anion (the conjugate base) and hydronium ion, H 3 O + . The ions formed can conduct electricity. So, the resulting solution is an electrolyte solution. However, most acids are weak which means they only dissociate to a small extent. Consequently, the ion concentration in solution is small, and the electrical conductivity is also small. Weak acids are therefore weak electrolytes. Weak bases are similarly weak electrolytes. Ionic materials and strong acids and bases are strong electrolytes. Label each of the following materials as a strong or weak electrolyte, or as a non-electrolyte. (a) nitric acid, HNO 3 (b) lithium hydroxide, LiOH (c) ethanol, C 2 H 5 OH (d) potassium iodide, KI (e) ammonia, NH 3 (f) hypochlorous acid, HOCl (g) sodium hypochlorite, NaOCl Page 36 of 88
Solutions: 4.1 (a) Cl 2 (g). The bonding is covalent. This is a molecular gas. Chlorine gas consists of pairs of chlorine atoms covalently bonded to form molecules. (b) LiOH(s). Ionic and covalent bonding are present. This is an ionic material. Lithium hydroxide consists of Li + and OH − ions arranged in a lattice. Hydroxide, OH − , is a diatomic anion with an oxygen atom covalently bonded to a hydrogen atom. (c) H 2 SO 4 (l). The bonding is covalent within the sulfuric acid molecules. Since the material is a liquid, there are also intermolecular forces holding the molecules together. These are weaker forces. At room temperature, the sulfuric acid molecules have enough thermal energy to easily move around one another. Consequently, sulfuric acid is a liquid at room temperature. (d) Fe(s). The bonding is metallic. The material is a metal. Iron atoms share valence electrons over vast arrays of nuclei arranged in a dense lattice to optimize the sharing. (e) CaCO 3 (s). Ionic and covalent bonding are present. This is an ionic material. Calcium carbonate consists of Ca 2+ and CO 3 2− ions arranged in a lattice. Carbonate, CO 3 2− , is a polyatomic anion with three oxygen atoms covalently bonded to a carbon atom. (f) C(diamond). Only covalent bonding is present. Diamond is a network covalent solid. It consists of a network (lattice) of carbon atoms held together by covalent bonds between neighboring atoms. (g) brass – an alloy of mostly copper, zinc and (sometimes) Sn. The bonding is metallic. The material is a metal. It consists of vast arrays of copper, zinc and (sometimes) Sn nuclei with valence electrons shared as a “sea” over the network. 4.2 (a) ethane, C 2 H 6 , and butane, C 4 H 10 . These materials form a solution. They are both non-polar molecules. (b) ethanol, C 2 H 5 OH, and water. They form a solution. They are both polar molecules. (c) carbon dioxide and carbon tetrachloride, CCl 4 . They form a solution, as they are both non-polar molecules. (d) lithium bromide, LiBr, and water. These form a solution, as LiBr is an ionic material that dissolves in water and splits into ions that are solvated by the polar water molecules. (e) sodium nitrate, NaNO 3 , and carbon tetrachloride, CCl 4 . These do not form a solution, as carbon tetrachloride is non-polar molecular liquid and the ionic NaNO 3 requires a polar solvent to dissolve it and solvate its ions. 4.3 (a) nitric acid, HNO 3 . Nitric acid is a strong electrolyte. It is a strong acid - it fully dissociates in water. (b) lithium hydroxide, LiOH. Lithium hydroxide is a strong electrolyte. It is an ionic material. It is also a strong base. However, since hydroxide is already ionic, reaction with water is not needed to produce an electrolyte solution. In the case of hydroxide, the products of reaction with water are water and hydroxide – there is no effect on the composition of the solution. Page 37 of 88
- Page 1 and 2: Chemistry Review Manual 2 nd Editio
- Page 3 and 4: Example 4.1: Type of bonding 31 4.2
- Page 5 and 6: 1. The Mole Early chemists discover
- Page 7 and 8: 2 Ca(s) + O 2 (g) → 2 CaO(s) It i
- Page 9 and 10: 1.5 Solutions Sometimes we are give
- Page 11 and 12: Problems: 1.1 How many grams of cal
- Page 13 and 14: 1.3 Mass of water produced = volume
- Page 15 and 16: The molar mass is determined from T
- Page 17 and 18: pV amount of H 2 consumed = n = RT
- Page 19 and 20: Solutions: 2.1 (a) These three gase
- Page 21 and 22: The amount of Al = (2/3) × 0.0043
- Page 23 and 24: 3.2 Strong and Weak Acids and Bases
- Page 25 and 26: Note that weak acids are conjugate
- Page 27 and 28: onds to the carbon atom. The result
- Page 29 and 30: Solutions: 3.1 (a) 2 Li(s) + Cl 2 (
- Page 31 and 32: 4. Bonding 4.1 Types of Bonding The
- Page 33 and 34: e.g. δ+ H H δ+ δ+ δ+ H H δ+ O
- Page 35: that pH = 7 tells us that the solut
- Page 39 and 40: 5. Chemical Equilibrium 5.1 Dynamic
- Page 41 and 42: Bases are characterized by the base
- Page 43 and 44: Suppose we have a table of equilibr
- Page 45 and 46: Whether we add or remove product, t
- Page 47 and 48: from which we get 4 4 = = 4 2 ⎛ x
- Page 49 and 50: The solution of this quadratic equa
- Page 51 and 52: consider dissolving CaCO 3 (s) in a
- Page 53 and 54: which gives Using the quadratic for
- Page 55 and 56: (c) H 2 S K a1 = 8.9 × 10 −8 App
- Page 57 and 58: ( ) 2 − 1.8× 10 ± 1.8× 10 + 4
- Page 59 and 60: 5.2 An equilibrium mixture of N 2 O
- Page 61 and 62: Solutions: 5.1 (a) K = p p p 2 BrCl
- Page 63 and 64: 5.5 CH 4 (g) + Br 2 (g) CH 3 Br(g
- Page 65 and 66: (b) HOCl(aq) + H 2 O(l) H 3 O + (
- Page 67 and 68: 6. Thermochemistry Chemical reactio
- Page 69 and 70: or which rearranges to q water =
- Page 71 and 72: 6.4 Energy Conservation - the First
- Page 73 and 74: The number of moles of H + (aq) is
- Page 75 and 76: Note that an element in the standar
- Page 77 and 78: ∆Hgas phase reaction ≅ 2 D[C-C]
- Page 79 and 80: Solutions: 6.1 Heat is related to t
- Page 81 and 82: 3 3 × ⎯⎯→ × − 2 2 o −1
- Page 83 and 84: 7. Math Skills Chemistry is a quant
- Page 85 and 86: The value of the gas constant used
(c) carbon dioxide and carbon tetrachloride, CCl 4<br />
(d) lithium bromide, LiBr, and water<br />
(e) sodium nitrate, NaNO 3 , and carbon tetrachloride, CCl 4<br />
4.3 Electrolytes can be strong or weak. For example, most acids are molecules that dissociate in<br />
water. They react with water to form an anion (the conjugate base) and hydronium ion, H 3 O + .<br />
The ions formed can conduct electricity. So, the resulting solution is an electrolyte solution.<br />
However, most acids are weak which means they only dissociate to a small extent.<br />
Consequently, the ion concentration in solution is small, and the electrical conductivity is also<br />
small. Weak acids are therefore weak electrolytes. Weak bases are similarly weak<br />
electrolytes. Ionic materials and strong acids and bases are strong electrolytes.<br />
Label each of the following materials as a strong or weak electrolyte, or as a non-electrolyte.<br />
(a) nitric acid, HNO 3<br />
(b) lithium hydroxide, LiOH<br />
(c) ethanol, C 2 H 5 OH<br />
(d) potassium iodide, KI<br />
(e) ammonia, NH 3<br />
(f) hypochlorous acid, HOCl<br />
(g) sodium hypochlorite, NaOCl<br />
Page 36 of 88
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