Zadanie 1
Liquid octane burns completely in oxygen to give carbon dioxide and liquid water. C8H18(l) + O2(g) → CO2(g) + H2O(l) What is the C8H18 : O2 ratio when the equation is balanced using the smallest whole-number coefficients? A. 1 : 12 B. 1 :…
Chemistry HL Paper 1, November 2023, TZ2
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Dodaj cały arkusz do zestawuZadanie 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 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 4
Naturally occurring bromine has Ar = 79.90 and contains only the isotopes 79Br and 81Br. What percentage of the atoms are 81Br? A. 10 % B. 45 % C. 55 % D. 90 %
Zadanie 5
The first three ionization energies of two elements, X and Y, are shown in the table. Which two elements are X and Y, in that order? A. Sodium and magnesium B. Magnesium and sodium C. Magnesium and silicon D. Silicon and magnesium
- Tabela do uzupełnienia
Zadanie 8
The wavelength of maximum absorbance of an aqueous solution of 0.10 mol dm−3 CuSO4 is measured. Which aqueous solutions would have a different wavelength of maximum absorbance? I. 0.050 mol dm−3 Cu(NO3)2 II.…
Zadanie 9
Which species is best described using resonance structures? A. NO3− B. H2S C. NF3 D. HCN
Zadanie 10
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 11
Between the molecules of which substance do only London (dispersion) forces act? A. XeF4 B. SF4 C. ClF3 D. IF5
Zadanie 12
Which Lewis formula of the perchlorate ion, ClO4−, is preferred on the basis of the lowest formal charges? A. Four Cl–O single bonds B. One Cl=O double bond and three Cl–O single bonds C. Two Cl=O double bonds and two Cl–O single bonds D. Three Cl=O…
Zadanie 13
Which bond angle is expected between the bonds formed by an sp hybridized carbon atom? A. 180° B. 109.5° C. 90° D. 120°
Zadanie 14
Which of these changes are exothermic? I. N2(g) + 3 H2(g) → 2 NH3(g) II. I2(s) → I2(g) III. H2O(g) → H2O(l) A. I and II only B. I and III only C. II and III only D. I, II and III
Zadanie 15
Which calculation gives the standard enthalpy change of formation of nitrogen monoxide, in kJ, from the data below? A. (+66) + (−114) B. 0.5 × (+66) + 0.5 × (−114) C. (+66) − (−114) D. 0.5 × (+66) − 0.5 × (−114)
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Zadanie 16
Which expression gives the enthalpy change, ΔH, of the forward reaction shown in the enthalpy profile? A. II − I B. I − II C. I − III D. III − II
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Zadanie 18
A reaction is not spontaneous at low temperatures but becomes spontaneous when the temperature is raised sufficiently. What are the signs of ΔH and ΔS for the reaction? A. ΔH positive, ΔS positive B. ΔH negative, ΔS negative C. ΔH positive, ΔS…
Zadanie 19
How does a catalyst increase the rate of a reaction? A. It increases the average kinetic energy of the colliding particles. B. It lowers the activation energy so that a greater proportion of collisions are successful. C. It makes the reaction more exothermic.…
Zadanie 20
Phosphine decomposes according to the equation 4 PH3(g) → P4(g) + 6 H2(g). The rate of the reaction can be expressed as the rate of change of the concentration of P4, Δ[P4]/Δt. Which expression is equal to this rate? A.…
Zadanie 21
A proposed mechanism for the reaction between nitrogen monoxide and hydrogen is 2 NO(g) → N2O2(g) (fast) N2O2(g) + H2(g) → N2O(g) + H2O(g) (slow) N2O(g) + H2(g) → N2(g) + H2O(g) (fast) The overall reaction is exothermic. Which potential…
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Zadanie 22
The temperature of a reaction mixture is raised and no catalyst is used. Which quantity changes, even though it does not depend on the concentrations of the reactants? A. Rate of reaction B. Order of reaction C. Rate constant D. Activation energy
Zadanie 23
The system below is at equilibrium. CH4(g) + H2O(g) ⇌ CO(g) + 3 H2(g) ΔH⊖ = +206 kJ Which change to the equilibrium mixture would produce more H2(g)? A. Adding a catalyst B. Increasing the pressure by decreasing the…
Zadanie 24
The system 2 A(g) ⇌ 3 B(g) + C(g) is at equilibrium with the concentrations of A, B and C all equal to 3.0 mol dm−3. Which value is Kc for this system? A. 3 B. 27 C. 9 D. 81
Zadanie 26
100 cm3 of each of two solutions are mixed. Which pair of solutions gives a buffer? A. 0.10 mol dm−3 CH3COOH and 0.10 mol dm−3 NaOH B. 0.20 mol dm−3 CH3COOH and…
Zadanie 27
The titration curve shown was recorded with a pH meter. Which type of titration does it represent? A. Weak acid added to a weak base B. Weak base added to a weak acid C. Strong base added to a weak acid D. Strong acid added to a weak base
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Zadanie 28
A weak acid has a concentration of 0.10 mol dm−3 and Ka = 1.0 × 10−7. Which value is closest to the pH of the solution? A. 1 B. 4 C. 7 D. 8
Zadanie 29
Magnesium ribbon is added to aqueous ethanoic acid. Which combination gives the role of the acid and a product formed from it? A. Oxidizing agent, H2(g) B. Oxidizing agent, CO2(g) C. Reducing agent, H2(g) D. Reducing agent, CO2(g)
Zadanie 30
A 1.0 mol dm−3 solution of magnesium chloride is electrolysed between inert electrodes. Which substance forms at the cathode? A. H2(g) B. Mg(s) C. Cl2(g) D. O2(g)
Zadanie 32
Which option classifies compound X as an amine and compound Y as an alcohol correctly? A. Primary amine and primary alcohol B. Secondary amine and primary alcohol C. Tertiary amine and primary alcohol D. Secondary amine and tertiary alcohol
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Zadanie 33
Butan-1-ol is heated with an acidified oxidizing agent, and the first product formed is distilled off as soon as it forms. Which compound is collected? A. CH3CH2COCH3 B. CH3CH2CH2CH2OH C. CH3CH2CH2CHO D. CH3CH2CH2COOH
Zadanie 34
Which compound reacts with HBr to form 2-bromo-2-methylbutane as the major product? A. Pent-2-ene B. 2-Methylbut-2-ene C. Pent-1-ene D. Cyclopentene
Zadanie 35
Which of these halogenoalkanes reacts fastest with aqueous hydroxide ions by an SN1 mechanism? A. CH3CH2CH2CH2Br B. CH3CH2CH2CH2I C. (CH3)3CBr D. (CH3)3CI
Zadanie 36
The structure of an isomer of 1,2-dichloroethene is shown. Which statement about this isomer is correct? A. It is the cis isomer and is polar. B. It is the cis isomer and is non-polar. C. It is the trans isomer and is polar. D. It is the trans isomer and is…
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Zadanie 37
The concentration of ethanoic acid in a sample of vinegar is determined by titration against a solution of sodium hydroxide of known concentration. Which procedure is most likely to produce a systematic error in the calculated concentration of the acid? A.…
Zadanie 38
In a precipitation reaction, further portions of the excess reactant are added after the limiting reactant has been completely consumed. Which graph shows how the amount of precipitate formed depends on the amount of excess reactant added? A. Graph A B. Graph…
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Zadanie 39
Which observation can be used to distinguish between the two enantiomers of a chiral compound in an achiral environment? A. The direction in which plane-polarized light is rotated B. Boiling point C. The mass-to-charge ratio of the molecular ion D. The number…
Zadanie 40
Use section 21 of the data booklet. The high resolution 1H NMR spectrum of an unknown compound is shown. Which compound is it? A. Butane B. Butanone C. Ethoxyethane D. Pentan-3-one
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