Chemistry Random Retrieval Y13

What are the products of the acid hydrolysis of methyl propanoate?

Step 8:

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

Which of these compounds have E/Z isomers?

(i) pent-2-ene,

(ii) 2-methylpent-2-ene,

(iii) 1,2-dichloropropene,

(iv) hex-1-ene

How many peaks would you expect to see in the ¹³C spectrym of 2,5-dimethyltetrahydrofuran?

This is the ¹H NMR spectrum of:

Which technique would you use to measure the rate of reaction for the hydrolysis of ethyl ethanoate?

The activation energy for the reaction

A + B -> C + D is 38 kJ mol^-1

The activation energy for the reaction

C + D -> A + B is 65 kJ mol^-1

There is a catalyst which lowers the activation energy for the reaction of A with B by 10 kJ mol^-1.

This shows that:

(i) the reaction of A with B is exothermic

(ii) the enthalpy change for the reaction of C with D is +27 kJ mol^-1

(iii) in the presence of the catalyst the activation energy for the reaction of C with D is 55 kJ mol^-1

(iv) the reaction of A with B is overall second order.

What are the units of k for this reaction?

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

Zn²⁺_(aq) + 2e^- <=> Zn_(s) E^ϴcell/V = -0.76

Cu²⁺_(aq) + 2e^- <=> Cu_(s) E^ϴcell/V = +0.34

Using oxidation numbers (states) work out the ratio of the species in the following half-equation.

H₂SO₄ + H⁺ + e^- => SO₂ + H₂O

From your calculation of ΔG in question 8, decide whether the reaction between high pressure steam and methane will be feasible at 1500^oC.

If this question is from a Random Retrieval, you can also carry out this calculation of Gibbs Energy change, ΔG by first working out values for ΔS^Ɵ and ΔH^Ɵ by selecting the appropriate data from the ‘Selection of Thermodynamic Data’ in TOOLS.

What enthalpy change is represented by the following equation?

2Na_(s) + ½ O_2(g)=> Na₂O_(s)

What enthalpy change is represented by the following equation?

Ca_(s) => Ca_(g)

If pressures are measured in pascals (Pa) what are the units of K_p for this equilibrium:

2H_2(g) + O_2(g) <=> 2H₂O_(g)

Consider the following reaction:

3NO_(g) => 2N₂O_(g) + NO_2(g)

The rate equation was found, by experiment:

rate = k [NO]²

Which of the following statements is/are true?

(i) There are two particles of the radical NO involved in the rate determining step

(ii) One particle of NO must be used up in a step that isn’t the rate determining step

(iii) Quadrupling [NO] raises the rate of nitrogen dioxide by, 2N₂O₂ production by 16 times

(iv) Tripling [NO] raises the rate of nitrous oxide, 2N₂O production by 8 times

By inspection of this experimental data, what is the rate equation for this reaction?

The activation energy for the reaction

A + B -> C + D is 38 kJ mol^-1

The activation energy for the reaction

C + D -> A + B is 65 kJ mol^-1

There is a catalyst which lowers the activation energy for the reaction of A with B by 10 kJ mol^-1.

This shows that:

(i) the reaction of A with B is exothermic

(ii) the enthalpy change for the reaction of C with D is +27 kJ mol^-1

(iii) in the presence of the catalyst the activation energy for the reaction of C with D is 55 kJ mol^-1

(iv) the reaction of A with B is overall second order.

The reaction of hydrogen gas with nitrogen monoxide gas is first order with respect to H_2(g) and second order with respect to NO_(g). It follows that:

(i) rate = k[H_2(g)][NO_(g)]²

(ii) doubling the concentration of NO_(g) increases the rate by a factor of 4

(iii) the overall order of reaction is 3

(iv) halving the concentration of hydrogen reduces the rate by a factor of 1.

A Maxwell-Boltzman plot shows the distribution of molecular energies in a sample of gas at a 300K. The curve showing the distribution at 310K:

(i) has a wider spread,

(ii) has a higher peak,

(iii) has the peak shifted to the right,

(iv) has a larger area under the curve.

In which of these reactions between pairs of reagents is the bond breaking homolytic?

(i) butan-1-ol with sodium bromide and concentrated sulfuric acid

(ii) catalytic cracking of hydrocarbons

(iii) bromine with ethene

(iv) bromine with hexane

In which of these reactions between pairs of reagents is the bond breaking heterolytic?

(i) hydrogen bromide with propene

(ii) hydrogen bromide and butan-1-ol

(iii) sodium hydroxide with 1-bromopropane

(iv) bromine with hexane

Which of these factors can make it hard to recycle polymeric materials from domestic waste:

(i) much plastic waste consists of containers which have a very low density,

(ii) it is hard for householders to distinguish one plastic from another

(iii) the presence of pigments and fillers often contaminates the pure polymers

(iv) polymers are so similar that no automatic methods of separation are practicable.

The monomer which polymerises to form a plastic which has a smooth, slippery surface and is used to give cooking utensils a non-stick surface is:

Which monomer polymerises to form this polymer?

---CH₂CHCl-CH₂CHCl-CH₂CHCl-CH₂CHCl---

If an amino acid is written as RCHNH₂CO₂H, in which of these amino acids is R a polar group?

(i) HSCH₂CHNH₂CO₂H

(ii) C₆H₅CH₂CHNH₂CO₂H

(iii) HOCH₂CHNH₂CO₂H

(iv) CH₃CHNH₂CO₂H

Which of these chemical species are electrophiles that react with the benzene ring

(i) Br⁺

(ii) Na⁺

(iii) NO₂⁺

(iv) H₃O⁺

Which of the listed liquids reacts with sodium borohydride NaBH₄ in a nucleophilic addition reaction?

(i) CH₃CH₂OH

(ii)CH₃COCH₃

(iii)CH₃CO₂H

(iv)CH₃CHO

A compound P, C₄H₈O, gave on oxidation an acid C₄H₈O₂. Which of the following are possible structures for P?

(i)CH₃CH₂CH₂CHO

(ii)CH₃COCH₂CH₃

(iii) (CH₃)₂CHCHO

(iv) CH₃CH=CHCH₂OH

Which of these aldehydes are isomers of pentan-2-one?

(i) pentanal

(ii) 2-methylbutanal

(iii) 3-methylbutanal

(iv) 2,2-dimethylbutanal