Chemistry Year 13 Random Retrieval

Excess LiAlH₄ in dry ether (this reacts similarly to NaBH₄ but is more reactive), converts propanoic acid to:

The reagent which converts ethanoic acid to ethanoyl chloride is:

If the molecule shown below is hydrolysed in hot sodium hydroxide, what are the main organic products?

Which of these conversions is an example of nucleophilic substitution?

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

Consider the following reaction:

2H₂O_2(g) => 2H₂O_(g)+ O_2(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

Consider the following reaction:

C₄H₉Cl_(aq) + OH^-_(aq) => C₄H₉OH_(aq) + Cl^-_(aq)

The rate equation was found, by experiment:

rate = k [C₄H₉Cl]

Which of the following statements is/are true?

(i) Increasing the concentrations of all reactants speeds up the nucleophilic substitution reaction

(ii) The mechanism probably has only one step

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

(iv) OH^- is required for the overall reaction to proceed

Consider the values of the equilibrium constant for this reversible reaction:

H_2(g) +I_2(g) <=> 2HI_(g)

Temperature: 500K, value of K_c = 160

Temperature: 1000K, value of K_c = 54.

This information shows that:

(i) HI decomposes rapidly at 500 K

(ii) Raising the temperature causes the equilibrium to shift to the left

(iii) Raising the pressure causes the equilibrium to shift to the right

(iv) The reaction is exothermic

Consider the following equilibrium:

N_2(g) + O_2(g) <=>2NO_(g)

5.00 x 10^-3 mol of N₂ was mixed with 4.00 x 10^-3 mol of O₂ and 11.0 x 10^-3 mol of NO and the mixture sealed in a container. The volume of the container was 0.500 dm³. The mixture was left to form a stable equilibrium. At this point, 9.00 x 10^-3 mol of NO was present in the mixture. The pressure was recorded as 45000 kpa

Calculate the value of K_p (no units) under these conditions.

The value of K_a for ethanoic acid = 1.7 x 10^-5 mol dm^-3 (pK_a = 4.8). During a titration of 20.0cm³ 0.1 mol dm^-3 solution of ethanoic acid with 0.1 mol dm^-3 sodium hydroxide, what is the pH of the mixture in the flask after adding 10.0 cm³ of the alkali?