Zadanie 1a
(i) Deduce the ionic equation, including state symbols, for the reaction of hydrogen bromide gas with water. (ii) Calculate the pH of 0.25 mol dm−3 hydrobromic acid. (iii) Explain why a solution of methanoic acid has a higher pH than…
Chemistry HL Paper 2, May 2023, TZ1
Zadania wzorowane na pytaniach z tego arkusza: te same umiejętności, format i punktacja, inne dane i kontekst. Treści arkusza IB nie publikujemy.
Dodaj cały arkusz do zestawuZadanie 1b
Outline one chemical test, other than the use of an indicator, that can distinguish between the two acids, and state the expected result.
Zadanie 1c
A neutralization curve for a weak acid, HA, titrated with a strong base is shown. (i) Estimate the pKa of HA. (ii) Explain, using an equation, why the pH changes very little when small volumes of strong base are added to the weak acid in the buffer…
- Materiał graficzny
Zadanie 2a
(i) Annotate and label the ground state orbital diagram of carbon below, using arrows to represent electrons. (ii) Sketch the shapes of the two types of occupied orbital identified in part (i) on the axes below, and state the orbital type for each.
- Materiał graficzny
Zadanie 2b
Explain why the first ionization energy decreases from beryllium to barium in group 2.
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 2d
Sulfur trioxide is manufactured industrially by the oxidation of sulfur dioxide. 2 SO2(g) + O2(g) ⇌ 2 SO3(g) ΔH⊖ = −198.0 kJ mol−1 (i) Outline what is meant by dynamic equilibrium. (ii) Deduce the Kc expression for this…
- Tabela do uzupełnienia
Zadanie 2e
The oxidation of sulfur dioxide in industry requires a catalyst. (i) State how a catalyst increases the rate of this reaction. (ii) Sketch a Maxwell-Boltzmann distribution curve showing the activation energies with and without a catalyst. (iii) Suggest how the…
- Materiał graficzny
Zadanie 3a
Halogenoalkanes form a homologous series. (i) Outline the meaning of homologous series. (ii) State the preferred IUPAC name of each of the two compounds shown. (iii) State which of the two compounds contains a chiral carbon atom and identify that carbon atom…
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Zadanie 3b
Identify the reagents for each step.
Zadanie 3c
(i) Identify the type of reaction that takes place in step 1. (ii) Sketch the mechanism of the reaction in step 1, using curly arrows to show the movement of electron pairs. (iii) Identify the products formed from the reaction of propan-1-ol and propanoic acid…
Zadanie 4a
State the oxidation state of manganese in the permanganate ion, MnO4−.
Zadanie 4b
(i) Outline why electrons flow from the iron half-cell to the copper half-cell when the two are connected by a wire. Use section 19 of the data booklet. (ii) Formulate equations for the reactions taking place at the anode (negative electrode) and at the…
Zadanie 4c
(i) Calculate the standard cell potential for the voltaic cell. Use section 19 of the data booklet. (ii) Calculate the standard Gibbs energy change, ΔG⊖, in kJ mol−1, for the cell reaction. Use sections 1 and 2 of the data…
Zadanie 5a
(i) Draw one Lewis (electron dot) structure of the sulfate ion. (ii) Calculate the percentage of oxygen present in the double salt. (iii) Determine the empirical formula of the double salt. Use section 7 of the data booklet. (iv) The molar mass of the…
Zadanie 5b
A 1.50 g sample of the double salt was dissolved in distilled water. Aqueous barium chloride was then added in excess, so that all the sulfate ions were precipitated as barium sulfate. (i) Formulate an ionic equation, including state symbols, for…
Zadanie 6a
Hydrogen sulfide, H2S, is removed from natural gas by burning it in air to form sulfur dioxide. (i) Determine the standard enthalpy change of reaction, ΔH⊖, in kJ mol−1, for 2 H2S(g) + 3 O2(g) → 2 SO2(g) + 2 H2O(l),…
- Tabela do uzupełnienia
Zadanie 6b
The enthalpy change of combustion of ethanol was investigated in a school laboratory. A spirit burner containing ethanol was used to heat water in a metal can. A total of 0.0250 mol of ethanol was burned. The following data were recorded. (i) Calculate the…
- Tabela do uzupełnienia
- Materiał graficzny
Zadanie 7a
The skeletal formulae of two esters with the molecular formula C4H8O2 are shown. (i) Deduce the number of signals you would expect in the 1H NMR spectrum of each compound. (ii) Outline why infrared spectroscopy is not used to differentiate between…
- Materiał graficzny
Zadanie 8
The rate constant, k, for the alkaline hydrolysis of ethyl ethanoate was determined at several temperatures. The processed data are shown in the graph. Determine the activation energy for this reaction, stating the units. Use sections 1 and 2 of the data…
- Materiał graficzny
Zadanie 9a
A colorimeter is set to a wavelength of 550 nm. Explain why it cannot be used to follow reactions of compounds of Sc3+. Use section 5 of the data booklet.
Zadanie 9b
Bromine radicals form when the bond in a bromine molecule is broken by ultraviolet light. The energy needed to break the bond in one molecule of Br2 is 3.21 × 10−19 J. (i) Calculate the minimum frequency of light needed to break this…
- Materiał graficzny