Physical Chemistry & Transition Elements Random Retrieval

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)?

Can MnO₄^-_(aq) oxidise water into H₂O_2(aq) in acidic condition?

What temperature is required for the determination of a standard cell potential, E^ϴcell/V?

[1] 298K

[2] 20^oC

[3] 273K

[4] 298 ^oC

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (For this quiz, you will need to open or download the Data Sheet, ‘A Selection of Standard Electrode Potentials’. This can be found in TOOLS>Data Sheets)

Which chemical species is the most powerful reducing agent?

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

Cr₂O₇^2- + H⁺ + e^- => Cr³⁺

+H₂O

Look at the chemical equation below.

CH_4(g) + H₂O_(g)=> CO_(g)+ 3H_2(g)

By selecting the appropriate data from the ‘Selection of Thermodynamic Data’ in TOOLS, calculate the entropy change, ΔS^Ɵ for the process. Take care with states!

From your calculation of ΔG in question 3, decide whether a solid dry sample of NaHCO_3(s) will decompose or will be thermally stable in the oven at 100^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.

For the following equilibrium K_c = 25.0 mol^-2 dm⁶ at a particular temperature.

CO_(g) + 2H_2(g) <=> CH₃OH_(g)

Which of these changes of conditions alter the value of K_c?

(i)Raising the concentration of hydrogen

(ii)Adding a catalyst

(iii)Raising the pressure

(iv)Lowering the temperature

For the equilibrium: CaCO_3(s) <=> CaO_(s) + CO_2(g)

What value should go in the blank box in the table?

The activation energy for the reaction of H_2(g) with I_2(g) is 120 kJ mol^-1. The standard enthalpy change for the reaction is +53 kJ mol^-1.

What is the activation energy for the decomposition of hydrogen iodide into its elements?