Homework 1

I’ll help you solve these questions following the same numbering as in the PDF. Let me break them down systematically:

1 a)

i) Silver chloride: AgCl
ii) Barium sulfate: BaSO₄
iii)

• Calcium carbonate: CaCO₃
• Copper (II) fluoride: CuF₂
• Sodium carbonate: Na₂CO₃
• Silver phosphate: Ag₃PO₄
• Ammonium sulfate: (NH₄)₂SO₄
• Magnesium phosphate: Mg₃(PO₄)₂
• Aluminium hydroxide: Al(OH)₃
• Iron(III) bromide: FeBr₃

1 b) Electronic configurations:
i) ²³₁₁Na: 2, 8, 1
ii) ³²₁₆S: 2, 8, 6
iii) ³⁹₁₉K: 2, 8, 8, 1

2. Balanced chemical equations:
   i) C + O₂ → CO₂
   ii) CO₂ + C → 2CO
   iii) Fe₂O₃ + 3CO → 2Fe + 3CO₂
3. Calculations:

• Number of moles of Al₂O₃ in 51g:
• Molar mass of Al₂O₃ = (2 × 27) + (3 × 16) = 102 g/mol
• Number of moles = 51/102 = 0.5 moles
• Number of particles in 0.5 moles of NaCl:
• Number of particles = 0.5 × 6.022 × 10²³
• = 3.011 × 10²³ particles

2. Calculate the mass of:
   i) 2 moles of calcium carbonate:

• Molar mass of CaCO₃ = 40 + 12 + (3 × 16) = 100 g/mol
• Mass = 2 × 100 = 200g

ii) 0.25 mole of water:
* Molar mass of H₂O = (2 × 1) + 16 = 18 g/mol
* Mass = 0.25 × 18 = 4.5g

5. For CaCO₃:

• Given: 0.1 moles = 10g
• Molar mass = mass/number of moles
• = 10/0.1 = 100 g/mol

c) For CaO:

• Given: 0.05 moles = 2.8g
• Molar mass = 2.8/0.05 = 56 g/mol

1. Relative molecular/formula mass:
   a) i) C₂H₅OH = (2 × 12) + (6 × 1) + 16 = 46
   ii) CH₃COOCH₂CH₃ = (4 × 12) + (8 × 1) + (2 × 16) = 88
   iii) CH₃CH₂COOH = (3 × 12) + (6 × 1) + (2 × 16) = 74
   iv) CH₃CH=CH₂ = (3 × 12) + (6 × 1) = 42

b) i) Na₂CO₃ = (2 × 23) + 12 + (3 × 16) = 106
ii) Ca(OH)₂ = 40 + (2 × 16) + (2 × 1) = 74
iii) (NH₄)₂SO₄ = (2 × 14) + (8 × 1) + 32 + (4 × 16) = 132

Would you like me to explain any of these calculations in more detail?