Chemistry Random Retrieval Y13

Which monomer polymerises to form this polymer?

---CH₂CHCl-CH₂CHCl-CH₂CHCl-CH₂CHCl---

In which of these organic compounds are all the bonds non-polar?

(i) 1-bromobutane

(ii) butene

(iii) butan-2-ol

(iv) butane

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

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

Consider the following equilibrium:

H_2(g) + I_2(g)<=>2HI_(g)

1.50 mol of HI was placed in a sealed vessel and allowed to decompose. At equilibrium, 0.500 mol of HI remained in the vessel

Calculate the value of the mole fraction of HI present in the mixture under these conditions.

pH = 2.9 for a solution which contains equal concentrations of chlorethanoic acid and sodium chlorethanoate. What is the pH of the solution after mixing it with twice its own volume of pure water?

These are four values for the hydration enthalpies of ions:

-361 kJ mol^-1, -559 kJ mol^-1, -2003 kJ mol^-1, -2537 kJ mol^-1.

These ions from left to right are:

What enthalpy change is represented by the following equation?

½ Br_2(l) => Br_(g)

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Is Cu²⁺_(aq) capable of oxidising Ag_(s)?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Which chemical species is most resistant to oxidation?

Consider the following 3 equilibria, all involving metallic copper or its ions:

Cu²⁺_(aq) + e^- <=> Cu⁺_(aq) E^ϴ/V = +0.15

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

Cu⁺_(aq) + e^- <=> Cu_(s) E^ϴ/V = +0.52

An aqueous solution of the colourless compound, CuCl_(s) was prepared and the solution was left to stand for a period in a sealed colourless glass bottle.

After the solution was left to stand, the contents of the bottle would have the following appearance:

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

S₂O₃^2- => S₄O₆^2- + e^-

When four bromide ions combine with a cobalt(II) ion

(i) the charge on the complex ion is 2-

(ii) the shape of the complex ion is tetrahedral

(iii) the coordination number of the cobalt atom is 4

(iv) the name of the complex is the tetrabromocobalt (II) ion

Consider the following equilibrium for the Haber-Bosch process:

3H_2(g) + N_2(g) <=>2NH_3(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 K_p (in units: kPa^-2) under these conditions.

Consider the following reaction:

2ICl_(g) + H_2(g) => HCl _(g)+ I_2(g)

The rate equation was found, by experiment:

rate = k [ICl] [H₂]

Which of the following statements is/are true?

(i) There are two particles involved in the rate determining step

(ii) There are two IClparticles involved in the rate determining step

(iii) IClparticles must be involved in involved in more than one step

(iv) The rate of production of I_2(g) doubles when both [ICl] and [H] double

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

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

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.

For which of these reactions can the rate of reaction be studied by collecting one of the products over water in a graduated tube (or measuring cylinder) inverted in a trough of water?

(i) Na₂SO_3(s) + 2HCl_(aq) -> 2NaCl_(aq) + SO_2(g) + H₂O_(l)

(ii) Zn_(s) + H₂SO_4(aq) -> H_2(g) + ZnSO_4(aq)

(iii) 2KCl_(s) + H₂SO_4(l) -> KHSO_4(s) + HCl_(g)

(iv) CaCO_3(s) + 2HNO_3(aq) -> Ca(NO₃)_2(aq) + CO_2(g) + H₂O_(l)

Thiosulfate ions react with acid to produce a precipitate of sulfur. The following volumes of sodium thiosulfate solutions are mixed in separate small flasks with 10 cm³ samples of 2.0 mol dm^-3 hydrochloric acid together with enough water to make the total volume 50 cm³.

In which flask does the precipitate of sulfur form fastest?

This is the ¹H NMR spectrum of:

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

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 changes represents a termination step of a chain reaction?

(i) CH₃^. + CH₃^. -> CH₃CH₃

(ii) CH₃^. + Br₂ -> CH₃Br + Br^.

(iii) Br^. + Br^. -> Br₂

(iv) Br^. + CH₄ -> CH₃^. + HBr

In which of these organic compounds are all the bonds non-polar?

(i) 1-bromobutane

(ii) butene

(iii) butan-2-ol

(iv) butane

Methane reacts with chlorine in the presence of ultraviolet light. The reactive chemical species which attacks methane molecules during the reaction is:

Which of these phrases describes the tertiary structure of a protein?

Which of the following molecules is/are examples of 2^o amines?

(i) 

(ii)

(iii) 

(iv) 

Ethyl ethanoate is heated under reflux with excess aqueous sodium hydroxide. The resulting solution is distilled. The distillate contains:

Which types of alcohol, when heated under reflux with acidified potassium dichromate(VI), turn the colour of the solution from orange to green?