Electrolytes and Dissolving: Quiz
Seven questions on electrolytes, hydration, ion concentrations and energy changes on dissolving, with explanations.
Electrolytes and Dissolving: Quiz
7 questions
NaCl is a strong electrolyte, fully split into ions. Ethanoic acid is only partly ionized, sugar forms no ions and pure water has very few.
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Answer: 0.10 mol/L NaCl
NaCl is a strong electrolyte, fully split into ions. Ethanoic acid is only partly ionized, sugar forms no ions and pure water has very few.
Ethanol dissolves as molecules and does not ionize. The others are a strong base, a strong acid and a soluble salt.
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Answer: Ethanol
Ethanol dissolves as molecules and does not ionize. The others are a strong base, a strong acid and a soluble salt.
The hydrogen atoms carry a partial positive charge (δ+), attracted to the negative chloride ion.
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Answer: Hydrogen atoms
The hydrogen atoms carry a partial positive charge (δ+), attracted to the negative chloride ion.
Each FeCl₃ gives three Cl⁻ ions: 3 × 0.150 mol/L = 0.450 mol/L.
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Answer: 0.450 mol/L
Each FeCl₃ gives three Cl⁻ ions: 3 × 0.150 mol/L = 0.450 mol/L.
CaCl₂ gives 3 ions per formula unit (0.30 mol/L of ions); NaCl gives 2 (0.20 mol/L); ethanoic acid gives very few; glucose gives none.
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Answer: CaCl₂
CaCl₂ gives 3 ions per formula unit (0.30 mol/L of ions); NaCl gives 2 (0.20 mol/L); ethanoic acid gives very few; glucose gives none.
A warmer solution means dissolving is exothermic: the energy released by hydrating the ions exceeds the energy needed to separate them.
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Answer: Hydration releases more energy than breaking the lattice needs
A warmer solution means dissolving is exothermic: the energy released by hydrating the ions exceeds the energy needed to separate them.
n = 10.0 g ÷ 80.05 g/mol = 0.1249 mol; q = 0.1249 mol × 25.7 kJ/mol = 3.21 kJ.
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Answer: 3.21 kJ
n = 10.0 g ÷ 80.05 g/mol = 0.1249 mol; q = 0.1249 mol × 25.7 kJ/mol = 3.21 kJ.