Chemistry Year 13 Random Retrieval

A sample of propan-2-ol was heated under reflux with an acidified, aqueous solution of potassium dichromate(VI). The resulting mixture was then distilled. The distillate contained:

(i) propanoic acid

(ii) propanone

(iii) propanal

(iv) water

Breaking down a polypeptide into amino acids by heating with dilute hydrochloric acid is an example of:

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

Step 10:

Which of these molecules are polar?

(i) trans but-2-ene,

(ii) trans 1,2-dichloroethene,

(iii) cis but-2-ene,

(iv) cis 1,2-dichloroethene

Consider the following equilibrium:

2SO_2(g) + O_2(g) <=>2SO_3(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 K_p (in units: kPa^-1) under these conditions.

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_c (in units: mol^-2 dm⁶) under these conditions.

Look at the chemical equation below.

CH_4(g) + H₂O_(g)=> CO_(g)+ 3H_2(g)

Calculate the temperature at which this process just becomes feasible.

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

In the anti-cancer complex compound [Pt(NH₃)₂Cl₂]

(i) the Pt, N and Cl atoms lie in one plane

(ii) the N-Pt-N angle is 180^o

(iii) the Cl-Pt-Cl angle is 90^o

(iv) the coordination number of platinum is zero

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 reduction?