Zadanie 1a
Determine the mass of sodium thiosulfate pentahydrate, Na2S2O3 ⋅ 5 H2O, needed to prepare 250.0 cm3 of a 0.2000 mol dm−3 solution.
- Materiał graficzny
Molar mass and mole calculations
Use molar mass in g mol⁻¹ to convert between mass in grams, amount in moles and number of particles with n = m / M, and chain these conversions in multi-step problems.
Tę umiejętność sprawdza 39 zadań wzorowanych na arkuszach IB z lat 2022–2025.
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Zadanie 1d
For the AAS method, a series of standards of known concentration was prepared by diluting a stock solution of Cu2+ ions. The instrument was zeroed with deionized water and the absorbance of each standard was recorded. (i) Draw the line of best fit for…
- Materiał graficzny
Zadanie 3b
Each student used a different mass of the hydrated salt. The results of the whole class are shown below (Mr of H2O = 18.02). (i) Determine the two missing values in the table. The class results were plotted on the graph below. (ii) Draw a line of…
- Tabela do uzupełnienia
- Materiał graficzny
Zadanie 4c
Calculate the percentage by mass of hydrogen in compound Y, giving your answer to four significant figures. Use section 7 of the data booklet.
Zadanie 7b
A second sample of Z was converted completely into vapour at a known temperature and pressure. (i) 0.148 g of the vapour occupied 63.7 cm3 at 110 °C and a pressure of 1.00 × 105 Pa. Calculate the amount, in mol, of Z in this sample. Use…
Zadanie 1a
Calculate the mass of solid potassium hydroxide that has to be weighed out.
Zadanie 4
4.06 g of hydrated magnesium chloride, MgCl2 ⋅ 6 H2O (Mr = 203), is dissolved in water to make 0.250 dm3 of solution. What is the concentration of chloride ions, in mol dm−3, in this solution? A. 0.0400 B. 0.0800 C.…
Zadanie 1c
A student writing a report on chlorine as a disinfectant collects, from several websites and reference books, values for how much chlorine dissolves in pure water at various temperatures. (i) Identify one difficulty in comparing the solubility values from…
- Tabela do uzupełnienia
Zadanie 4
A cylinder contains 80 g of argon and 12.0 g of helium. What is the ratio of the number of argon atoms to the number of helium atoms in the cylinder? A. 0.15 B. 0.67 C. 1.5 D. 6.7
Zadanie 5b
The enthalpy of combustion of C15H32 is −10 040 kJ mol−1. (i) Calculate the maximum amount of energy that the complete combustion of 1.75 g of pentadecane can release. (ii) The energy from burning the 1.75 g sample is used to heat…
Zadanie 1c
At 150.0 °C and a pressure of 1.00 × 105 Pa, the vapour of A has a density of 2.45 × 103 g m−3. Determine the molar mass of A and hence its molecular formula. Use sections 1 and 2 of the data booklet.
Zadanie 2c
A second spirit burner contains hexane, C6H14, instead of butan-1-ol. Determine whether hexane would release more or less energy per gram than butan-1-ol. Use section 14 of the data booklet.
- Materiał graficzny
Zadanie 2a
Demonstrate that these data are consistent with the formula MgSO4 ⋅ 7 H2O.
- Materiał graficzny
Zadanie 2
Which compound has the highest percentage of carbon by mass? A. CH3CH2OH B. CH3CHO C. C3H8 D. C2H6
Zadanie 6b
The iodine number of a fat or oil is the mass, in grams, of iodine that reacts with 100 g of the fat or oil. It is a measure of the degree of unsaturation. A 3.50 g sample of peanut oil reacts completely with 65.5 cm3 of…
Zadanie 13b
Calculate the specific energy of ethane hydrate, in kJ g−1. Use section 14 of the data booklet.
Zadanie 13b
Cyclopentane is a component of petrol. Its specific energy, the energy released per kilogram of fuel burned, is 4.69 × 107 J kg−1. Calculate the enthalpy of combustion of cyclopentane, C5H10, in kJ mol−1. Use…
Zadanie 1
A sample of ammonium sulfate, (NH4)2SO4, has a mass of 66.1 g. Mr = 132.17 How many moles of ammonium ions are present in the sample? A. 0.25 B. 0.50 C. 1.00 D. 1.50
Zadanie 4
A steel cylinder of volume 5.0 dm3 holds 2.0 g of helium at 27 °C. Ar(He) = 4.0; R = 8.31 J K−1 mol−1; PV = nRT Which expression gives the pressure of the helium, in Pa? A.…
Zadanie 1
What is the mass of one molecule of white phosphorus, P4? Use NA = 6.02 × 1023 mol−1. A. 5.1 × 10−23 g B. 2.1 × 10−22 g C. 4.9 × 1021 g D. 7.5 × 1025 g
Zadanie 1b
A sample of 0.296 g of a volatile organic liquid, Y, was vaporized completely at 87.0 °C and 100.0 kPa. The volume of the vapour was 123 cm3. Determine the molar mass of Y.
Zadanie 3
A gas sample gave the experimental results below. Which expression gives the molar mass of the gas, in g mol−1? Ideal gas constant R = 8.31 J K−1 mol−1, PV = nRT A. B.…
- Tabela do uzupełnienia
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 7a
Glucose, C6H12O6, is oxidized in the body by respiration to carbon dioxide and water. The standard enthalpy of combustion of glucose is −2803 kJ mol−1. Determine the energy, in kJ, released by the complete oxidation of 12.5 g of glucose.
Zadanie 14c
The global warming potential (GWP) of a gas compares the heat it absorbs with the heat absorbed by an equal mass of carbon dioxide. The GWP of the refrigerant C2H2F4 is approximately 1300. Estimate the heat absorbed by one mole of C2H2F4 relative…
Zadanie 17b
One antacid tablet contains 1.50 g of calcium carbonate and a second tablet contains 1.50 g of magnesium hydroxide. Show by calculation that the tablet of magnesium hydroxide would neutralize more hydrochloric acid than the tablet of calcium carbonate.
Zadanie 1b
Calculate the percentage by mass of carbon in ethanoic acid.
Zadanie 1b
Calculate the mass percentage of oxygen in ethanoic acid.
Zadanie 2
Metal M reacts with 8.00 g of oxygen to produce 28.0 g of the oxide MO2. What is the relative atomic mass of M? A. 20 B. 40 C. 80 D. 160
Zadanie 2
When 10.65 g of chlorine gas is passed over a metal M, 13.35 g of the compound MCl3 is formed and no reactant is left over. Which value is the relative atomic mass of M? A. 9 B. 18 C. 27 D. 133
Zadanie 3
A mixture of 44.1 g of propane and 192 g of oxygen is ignited and reacts until one reactant is used up, according to the equation. C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l) Which substances are present in the vessel once the reaction has finished? A.…
Zadanie 3
A sealed vessel contains 4.41 g of propane and 24.0 g of oxygen, which react according to the equation. C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l) Which substances are present in the vessel after the reaction is complete? A. CO2(g) and H2O(l)…
Zadanie 4c
Naturally occurring sulfur is a mixture of several isotopes. A sample was enriched in , giving the following composition: (i) Calculate the relative atomic mass of the enriched sample to two decimal places. (ii) The abundance of…
- Tabela do uzupełnienia
Zadanie 1
A 2.51 g sample of zinc carbonate is heated until it reaches constant mass. ZnCO3(s) → ZnO(s) + CO2(g) What is the mass of solid remaining? A. 0.88 g B. 1.63 g C. 2.51 g D. 3.39 g
Zadanie 1b
In an experiment, calcium turnings were heated strongly in a crucible with a lid. The following data were recorded: (i) Calculate the amount of calcium, in mol, that was used. (ii) Determine the percentage uncertainty in the final mass of product. (iii) Assume…
- Tabela do uzupełnienia
Zadanie 1a
Calculate the percentage by mass of nitrogen in ammonium chloride. Use section 7 of the data booklet.
Zadanie 3
How many moles of carbon dioxide are produced by the complete combustion of 14.5 g of butane, C4H10? Mr = 58 A. 0.25 B. 0.50 C. 1.00 D. 1.25
Zadanie 5a
A sample of coal contains 1.20 % sulfur by mass. Calculate the amount, in mol, of sulfur dioxide produced when 400.0 g of this coal undergoes complete combustion. S(s) + O2(g) → SO2(g)