Physical Chemistry & Transition Elements Random Retrieval

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells? These half-cells are those involved in Hydrogen Fuel Cells when operated in acidic conditions?

H⁺_(aq) + e^-<=> ½H_2(g) (acidic conditions) E^ϴ/V = 0.00

O_2(g)+ 4H⁺_(aq) + 4e^-<=>2H₂O_(g) (acidic conditions) E^ϴ/V = +1.23

Using your half-equations from questions 4 & 5, balance the REDOX equation below.

BrO₃^- + H⁺ + C₂O₄^2- => CO₂ + Br^- + H₂O

Select the integers that represent the ratio of species in the overall balanced REDOX equation.

If this question appears in a Random Retrieval quiz, you would be best constructing separate half-equations for the species that is oxidised and the species that is reduced prior to working out the overall REDOX equation.

In an EDTA complex with a copper(II) ion

(i) there are six ligand molecules,

(ii) there are four dative bonds between oxygen atoms and the metal ion,

(iii) the overall charge on the complex ion is zero,

(iv) there are two dative bonds between nitrogen atoms and the metal ion

Which first-row d-block metal forms hydrated ions in the +3 state which undergo a ligand exchange reaction to form a deep red complex ion with thiocyanate ions, SCN^-.

Which first-row d-block metal forms a reddish oxide in the +1 state which dissolves in dilute sulfuric acid to give a blue solution and a red-brown precipitate?

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.

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

2Cl_2(g)=> 4Cl_(g)

What enthalpy change is represented by the following equation?

2Na_(s) + ½ O_2(g)=> Na₂O_(s)

What is the pH of a 0.01 mol dm^-3 solution of sodium hydroxide given that Kw = 1.0 x 10^-14 mol²dm^-6 at 298K?

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