Chemistry Random Retrieval Y13

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Chemistry Year 13 Random Retrieval

This quiz contains all the questions in the year 13 chemistry section. The website will pick 10 questions at random.

1 / 10

Which of these chemical species are electrophiles which add to alkenes?

(i) bromine molecules

(ii) sulfuric acid molecules

(iii) hydrogen bromide molecules

(iv) sulfate ions

2 / 10

This is the 1H NMR spectrum of:

3 / 10

When a sample of calcium carbonate reacts with dilute hydrochloric acid, 144 cm3 of carbon dioxide form in 20 seconds at room temperature and pressure.

What is the rate of loss of hydrochloric acid in moles per second. (Volume of 1 mol gas under these conditions = 24 000 cm3)

4 / 10

Which of these are examples of kinetic stability?

(i) A solution of hydrogen peroxide can be stored at room temperature

(ii) Hydrogen does not ignite in air at room temperature

(iii) Aluminium does not corrode in moist air

(iv) Magnesium oxide does not decompose on heating

5 / 10

Kp = 4 atm for the dissociation of N2O4 at 350 K when the equilibrium is described by this equation.

N2O4(g) <=> 2NO2(g)

What is the value of Kp for this equilibrium:

2NO2(g) <=> N2O4(g)?

6 / 10

Which of the following are examples of heterogeneous equilibria?

(i) CaCO3(s) <=> CaO(s) + CO2(g)

(ii) 2CrO42-(aq) + 2H+(aq) <=> Cr2O72-(aq) + H2O(l)

(iii) Ag+(aq) + Fe2+(aq) <=> Ag(s) + Fe3+(s)

(iv) Co2+(aq) + 6NH3(aq) <=> [Co(NH3)6]2+(aq)

7 / 10

Consider the following equilibrium:

2SO2(g) + O2(g) <=>2SO3(g)

8.00 mol of SO2 was mixed with 5.00 mol of O2 and the mixture sealed in a heated vessel of volume of 1.00 dm3. The mixture was left until no further observable change in composition took place. The pressure was recorded as 200 kPa. At this point, 2.00 mol of O2 was present in the mixture.

Calculate the value of Kp (in units: kPa-1) under these conditions.

8 / 10

Consider the following equilibrium for the Haber-Bosch process:

3H2(g) + N2(g) <=>2NH3(g)

32.0 mol of H2 was combined with 12.0 mol of N2 and the mixture sealed and pressurised in a vessel of volume 2.00 dm3. The mixture was left until no further observable change in composition took place. At this point, 4.00 mol of NH3 was found to be present in the mixture The pressure was recorded as 200 000 kPa.

Calculate the value of Kp (in units: kPa-2) under these conditions.

9 / 10

Which of the first-row d-block metals forms aqueous ions which are mauve in the +2 state, green in the +3 state, blue in the +4 state and yellow in the +5 state?

10 / 10

What is the value of Eϴcell/V observed for a cell constructed from the following half-cells?

Fe3+(aq) + e- <=> Fe2+(aq) Eϴ/V = +0.77

MnO4-(aq) + 8H+(aq) + 5e- <=> Mn2+(aq) + 4H2O(aq) Eϴ/V = +1.51

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7

Physical Chemistry & Transition Elements Random Retrieval

This quiz contains all the questions in the Physical Chemistry & Transition Elements section. The website will pick 10 questions at random.

1 / 10

Salt bridges are required for a cell Eϴcell/V to be measured.

What statement best describes the action of a salt bridge?

2 / 10

What solution concentrations are required for the determination of a standard cell potential, Eϴcell/V?

3 / 10

Work out the ratio of the species in the following half-equation.

Cu => Cu2+ + e-

4 / 10

Which of these complex ions acts as an acid in aqueous solution?

(i) [Ni(NH3)6]2+

(ii) [Al(H2O)2(OH)4]-

(iii) [Ag(NH3)2]+

(iv) [Cr(H2O)6]3+

5 / 10

Calculate the value of the enthalpy change associated with the following equation?

N2(g) + 3H2(g) => 2NH3(g)

6 / 10

The standard enthalpy change when one mole of an ionic compound forms from free gaseous ions is called the:

7 / 10

Which of these compounds give an alkaline solution when mixed with water?

(i) NH4Cl

(ii) NH3

(iii) CH3CH2OH

(iv) CH3CO2Na

8 / 10

Consider the following equilibrium for the reaction that generates hydrogen for use in the Haber-Bosch Process:

CH4(g) + H2O(g) <=>CO(g) + 3H2(g)

100 mol of CH4 was mixed with 100 mol of H2O and 200 mol of H2.The mixture was given time to reach equilibrium. At this point, 350 mol of H2 was present in the mixture. The pressure inside the 1.20 m3 vessel was measured as 400 kPa

Calculate the value of Kp (in units: kPa2) under these conditions.

9 / 10

Consider the following reaction:

2H2O2(g) => 2H2O(g)+ O2(g)

The rate equation was found, by experiment:

rate = k [H2O2]

Which of the following statements is/are true?

(i) The mechanism must be multi step

(ii) Doubling [H2O] quadruples the rate of the reaction

(iii) [H2O] must be consumed in more than one step

(iv) The mechanism probably has only one step

10 / 10

What is the value of the rate constant, k for this reaction at this temperature?

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10

Organic Chemistry & Analysis Random Retrieval

This quiz contains all the questions in the Organic Chemistry & Analysis section. The website will pick 10 questions at random.

1 / 10

Which of these compounds are chiral?

(i) CH2Cl2

(ii) CH2ClBr

(iii)CHCl2F

(iv) CH3CHClBr

2 / 10

Which of these compounds are chain isomers of 2-methylpentane

(i) hexane,

(ii) 2,2-dimethylpentane,

(iii) 2,3-dimethylbutane,

(iv) 2,2-dimethylpropane

3 / 10

The nitrating agent for benzene is a mixture of concentrated sulfuric and nitric acids. This mixture produces:

4 / 10

Which statement helps to explain why propene react with hydrogen bromide to form mainly 2-bromopropane and much less 1-bromopropane?

5 / 10

Step 5:

6 / 10

Step 6:

7 / 10

Step 8:

8 / 10

Which of these molecules does NOT consist of one or more chains of amino acids?

(i) The hormone insulin

(ii) The filaments in muscle fibres

(iii) The enzyme in saliva, amylase

(iv) The genetic material, DNA

9 / 10

In a peptide made up of a sequence of four amino acids the number of peptide bonds is:

10 / 10

Which of these compounds are functional group isomers?

(i) CH3CHCHOH

(ii) CH3CH2CHO

(iii) CH3COCH3

(iv) CH3CH2COCH3

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