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Dodaj cały arkusz do zestawuWhich statements about pure carbon dioxide, CO2, are correct? I. It can be separated into carbon and oxygen by filtration. II. Its carbon and oxygen atoms are present in the same fixed ratio in every sample. III. Its atoms of the two elements are…
A hydrocarbon has the empirical formula CH2 and a molar mass of 98.2 g mol−1. What is its molecular formula? A. C6H12 B. C7H16 C. C7H14 D. C8H16
What is the sum of the coefficients when this equation is balanced with the smallest whole numbers? A. 8 B. 9 C. 10 D. 12
Which species are present after 14 dm3 of ethyne has reacted with 20 dm3 of hydrogen to produce ethane? All gas volumes are measured at the same temperature and pressure. C2H2(g) + 2 H2(g) → C2H6(g) A. 14 dm3 of…
What is the correct number of subatomic particles in ? A. 30 protons, 32 electrons, 35 neutrons B. 30 protons, 28 electrons, 65 neutrons C. 35 protons, 28 electrons, 30 neutrons D. 30 protons, 28 electrons, 35 neutrons
Which electron transition produces the line of longest wavelength in the visible region of the hydrogen line emission spectrum? A. Transition A B. Transition B C. Transition C D. Transition D
Which element is in the f-block of the periodic table? A. U B. Ba C. Hf D. Rf
Equal amounts of each of the following oxides are added to separate samples of water of the same volume. Which oxide gives the solution with the lowest pH? A. CO B. SO3 C. K2O D. CO2
What is the correct formula for ammonium sulfate? A. (NH4)2SO4 B. NH4SO4 C. NH4(SO4)2 D. (NH3)2SO4
Which bond is the most polar? A. C−S B. C−Br C. C−Cl D. C−O
Which combination best describes SO32−? A. 4 electron domains around S, trigonal pyramidal, 107° B. 3 electron domains around S, trigonal planar, 120° C. 4 electron domains around S, tetrahedral, 109.5° D. 3 electron domains around…
A 52.0 g piece of zinc at 90.0 °C is dropped into 80.0 cm3 of water at 20.0 °C. The final temperature of the water is 24.0 °C. The specific heat capacity of zinc is…
What is the enthalpy change of reaction, ΔH⊖ in kJ mol−1, for the partial hydrogenation of ethyne to ethene? C2H2(g) + H2(g) → C2H4(g) ΔH⊖ = ? C2H2(g) + 2 H2(g) → C2H6(g)…
The enthalpy change of the reaction below is calculated from average bond enthalpies. H2(g) + Cl2(g) → 2 HCl(g) Average bond enthalpies: H−H 436 kJ mol−1, Cl−Cl 242 kJ mol−1, H−Cl…
Which change would decrease the rate of the reaction between zinc and dilute sulfuric acid? Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g) A. increasing the temperature of the acid from 20 °C to 30 °C B. grinding the zinc…
Which methods could be used to determine the rate of this reaction? CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g) I. measuring the decrease in mass of the reaction mixture II. measuring the change in absorbance of light by the solution in a…
The equilibrium constant for the reaction below is Kc = 280 at 700 K. 2 SO2(g) + O2(g) ⇌ 2 SO3(g) What is the value of the equilibrium constant at 700 K for the following reaction? 6 SO3(g) ⇌ 6 SO2(g) + 3 O2(g) A. B.…
Which products form in the reaction between nitric acid and calcium carbonate? A. Ca(NO3)2 + H2O + CO B. CaNO3 + H2O + CO2 C. Ca(NO3)2 + CO2 D. Ca(NO3)2 + H2O + CO2
A 10.0 cm3 sample of 0.0100 mol dm−3 nitric acid, HNO3(aq), is diluted with water to a final volume of 10.0 dm3. What is the change in pH? A. increases by 3 B. increases by 2 C. decreases by 2 D. decreases by 3
The following equations represent reactions that occur spontaneously. Zn(NO3)2(aq) + Mg(s) → Mg(NO3)2(aq) + Zn(s) Cu(NO3)2(aq) + Zn(s) → Zn(NO3)2(aq) + Cu(s) 2 AgNO3(aq) + Cu(s) → Cu(NO3)2(aq) + 2 Ag(s) What is the increasing order of…
Which statement is correct for a voltaic cell made from a zinc half-cell and a copper half-cell? The standard electrode potential of the zinc half-cell is more negative than that of the copper half-cell. A. Zinc is the cathode. B. Electrons flow through the…
What are the products of the electrolysis of molten lead(II) bromide, PbBr2(l)? A. Pb(l) + Br2(g) B. Pb2+(l) + 2 Br−(l) C. Pb2+(l) + Br2(g) D. Pb(l) + 2 Br−(l)
Which compounds belong to the same homologous series? A. CH3CH2COOH, CH3COOH, CH3CH2CH2COOH B. CH3COCH3, CH3CH2CHO, CH3CH2COCH3 C. CH3CH2OH, CH3CHO, CH3COOH D. CH3CH2Cl, CH2=CHCl,…
What is the name of this compound? BrCH2CH2CH(CH3)CH2CH3 A. 1-bromo-3-ethylbutane B. 5-bromo-3-methylpentane C. 1-bromo-3-methylpentane D. 1-bromo-2-ethylbutane
What is the organic product when butan-2-ol, CH3CH(OH)CH2CH3, is heated under reflux with an excess of an acidified oxidizing agent? A. CH3CH2CH2COOH B. CH3COCH2CH3 C. CH3CH2CH2CHO D. CH3CH(OH)CH2CH3
Which products may be formed during incomplete combustion of hexane, C6H14? A. CO2, CO and H2 B. CO, H2 and H2O C. C, CO and H2O D. C and H2
Four 25.0 cm3 samples of water were measured using a graduated cylinder and each was weighed. The masses were 24.4 g, 25.6 g, 24.8 g and 25.2 g. The density of water under the conditions of the…
A 25.0 cm3 sample of ethanol weighed 19.725 g at 20 °C. What is the density of ethanol in g cm−3? A. 0.79 B. 0.789 C. 0.7890 D. 0.78900