Zadanie 1c
The final step can be summarized as: 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g) ΔH⊖ = −138 kJ mol−1 Describe the types of bonding found in the concentrated aqueous nitric acid product.
Intermolecular forces and physical properties
Rank the strengths of London dispersion forces, dipole-dipole forces and hydrogen bonds for similar molar masses, and use them to explain and compare the boiling points, volatility, solubility and electrical conductivity of covalent substances.
Tę umiejętność sprawdzają 23 zadania wzorowane na arkuszach IB z lat 2022–2026.
Zadania sprawdzające tę umiejętność: 23 Otwórz w wyszukiwarce z filtrami
Zadanie 3c
Pentan-2-ol can form by reacting pent-1-ene with water in the presence of an acid catalyst. CH2=CHCH2CH2CH3(g) + H2O(l) → CH3CH(OH)CH2CH2CH3(aq) ΔH⊖ = −84 kJ mol−1 (i) Explain why increasing the temperature would increase…
Zadanie 4c
The compounds butan-1-ol and ethoxyethane have the same molar mass. Their structures are shown below. Explain, with reasons, why butan-1-ol has a higher boiling point than ethoxyethane.
- Materiał graficzny
Zadanie 8
The three isomers of C4H8O in the table have the same molar mass. What is the reason for the increase in boiling points? A. Increase in the number of covalent bonds per molecule B. Increase in molar mass C. Increase in the strength of intermolecular…
- Tabela do uzupełnienia
Zadanie 1a
At room temperature hydrogen cyanide is a liquid that evaporates readily, whereas ethyne, C2H2, which has almost the same molar mass, is a gas that boils at −84 °C. (i) Draw the Lewis formula of the hydrogen cyanide molecule, showing all valence…
Zadanie 4
Which row shows the gas and the conditions under which its behaviour is closest to that of an ideal gas? A. Hydrogen fluoride, HF, at high pressure and low temperature B. Methane, CH4, at high pressure and low temperature C. Hydrogen fluoride,…
Zadanie 8
Hydrogen fluoride boils at 20 °C, whereas hydrogen chloride boils at −85 °C. Which type of intermolecular force accounts for the much higher boiling point of hydrogen fluoride? A. Hydrogen bonding B. Dipole-dipole forces C. London (dispersion) forces D.…
Zadanie 1d
Suggest why hot-tub owners rarely add bromine itself to the water and instead use solid tablets that release HOBr.
Zadanie 5b
The graph shows the boiling points of five straight-chain carboxylic acids and of the five methyl esters that have the same relative formula masses as the acids. (i) Outline why the carboxylic acids have higher boiling points than the esters with the same…
- Materiał graficzny
Zadanie 2c
Methanol and butan-1-ol are members of the same homologous series. (i) Name the class of compound and the functional group that characterize this series. (ii) State the strongest intermolecular force between molecules of either alcohol. (iii) Predict one type…
Zadanie 4b
Butane, C4H10, and propenal have similar molar masses, yet propenal is the less volatile. Compare and contrast the intermolecular forces in the two substances to account for this difference.
Zadanie 6c
Pantothenic acid (vitamin B5) is added to some processed foods. Its structure is shown. Predict, giving one reason, whether pantothenic acid is soluble in vegetable oil.
- Materiał graficzny
Zadanie 9
Citric acid gives lemon juice its sharp taste. It dissolves very readily in water. Its structure is shown. Explain why citric acid is soluble in water, with reference to its structure.
- Materiał graficzny
Zadanie 12
Which pair of liquids is immiscible? A. CH3OH and CH3CH2CH2OH B. CH3COCH3 and H2O C. C6H14 and CCl4 D. C6H12 and H2O
Zadanie 17b
Paracetamol and phenacetin are two analgesics with similar structures. Predict, giving a reason, which of the two compounds is more soluble in water.
- Materiał graficzny
Zadanie 2c
(i) State the electron domain geometry of the water molecule. (ii) Deduce the Lewis (electron dot) structure of water and sketch its 3D molecular shape. (iii) Explain, with reference to the forces between molecules, why water has a higher boiling point than…
Zadanie 7b
Spot X is known to be either glutamine or isoleucine. The structures of the two amino acids are shown. Predict, with reference to the structures, which amino acid is more likely to be in spot X. Use the RF values in the table.
- Materiał graficzny
Zadanie 9
Which compound is both volatile and soluble in water? A. C6H14 B. KBr C. SiO2 D. CH3CH2OH
Zadanie 25
Which statement best explains why the boiling points of the straight-chain alkanes rise from methane to pentane? A. The carbon–hydrogen bonds become stronger B. Longer molecules have more electrons, so the London (dispersion) forces between them are stronger…
Zadanie 1d
Ethanoic acid and propanone, CH3COCH3, each contain a C=O group, and their molar masses are close. (i) Considering the strongest intermolecular forces in each liquid, explain why propanone boils at a much lower temperature than ethanoic acid.…
Zadanie 1d
Ethanoic acid and propanone, CH3COCH3, both contain a carbonyl group and have similar molar masses. (i) Explain, in terms of the strongest intermolecular forces present in each liquid, why propanone boils at a much lower temperature than ethanoic acid.…
Zadanie 13
Which substance is highly volatile in its pure state and gives a solution with high electrical conductivity in water? A. CH3Br B. KBr C. H2S D. HBr
Zadanie 4a
(i) Deduce the structural formula and the empirical formula of B. (ii) Explain, with reference to Le Châtelier’s principle, the effect on the yield of B of using dilute rather than concentrated sulfuric acid as the catalyst. (iii) Compound A has a lower molar…
- Materiał graficzny