1.
State what is meant by lattice enthalpy. [1]
JD SCIENCE
Module 5 Physical chemistry and transition elements
Answer all questions. Show working. Answers are in a separate file on the Worksheets page — do not look at them until you have finished.
2.
State what is meant by Gibbs free energy. [1]
3.
State what is meant by the Arrhenius equation. [1]
4.
State what is meant by a half-cell. [1]
5.
State what is meant by EMF of a cell. [1]
6.
State what is meant by a buffer. [1]
7.
State what is meant by pH of a strong acid. [1]
8.
State what is meant by Ka. [1]
9.
State what is meant by a redox titration. [1]
10.
State what is meant by electrochemical series. [1]
11.
Grace is asked about lattice enthalpy in a OCR Chemistry paper.
(a) Describe lattice enthalpy. [2]
(b) Explain why lattice enthalpy is important in this topic. [3]
12.
Grace is asked about Gibbs free energy in a OCR Chemistry paper.
(a) Describe Gibbs free energy. [2]
(b) Explain why Gibbs free energy is important in this topic. [3]
13.
Grace is asked about the Arrhenius equation in a OCR Chemistry paper.
(a) Describe the Arrhenius equation. [2]
(b) Explain why the Arrhenius equation is important in this topic. [3]
14.
Grace is asked about a half-cell in a OCR Chemistry paper.
(a) Describe a half-cell. [2]
(b) Explain why a half-cell is important in this topic. [3]
15.
Grace is asked about EMF of a cell in a OCR Chemistry paper.
(a) Describe EMF of a cell. [2]
(b) Explain why EMF of a cell is important in this topic. [3]
16.
Grace is asked about a buffer in a OCR Chemistry paper.
(a) Describe a buffer. [2]
(b) Explain why a buffer is important in this topic. [3]
17.
pH of 0.020 mol dm⁻³ HCl [3]
18.
[H⁺] if pH=3.00 [3]
19.
ΔG if ΔH=−20 kJ, ΔS=−50 J K⁻¹, T=300 K [3]
20.
Ecell if 0.80 − (−0.76) [3]
21.
Ka = 1.8×10⁻⁵, [HA]=0.10. [H⁺] ≈ [3]
22.
Titration: 25.0 cm³ Fe²⁺ needs 20.0 cm³ of 0.0200 mol dm⁻³ MnO₄⁻. Moles MnO₄⁻ [3]
23.
Grace carries out a OCR-style required practical linked to thermodynamics, rates, electrode potentials and acids. This is a typical OCR required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
24.
Grace carries out collecting valid data for thermodynamics, rates, electrode potentials and acids. This is a typical OCR required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
25.
Grace carries out drawing a graph for thermodynamics, rates, electrode potentials and acids. This is a typical OCR required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
26.
Grace carries out evaluating a method about thermodynamics, rates, electrode potentials and acids. This is a typical OCR required-practical style question.
(a) Identify the independent variable and the dependent variable. [2]
(b) State one control variable and explain why it must be controlled. [2]
(c) Suggest one improvement or source of error and how it affects the result. [2]
27.
Compare lattice enthalpy with Gibbs free energy. [4]
28.
Compare Gibbs free energy with the Arrhenius equation. [4]
29.
Compare the Arrhenius equation with a half-cell. [4]
30.
Compare a half-cell with EMF of a cell. [4]
31.
Apply your knowledge of pH of a strong acid to this situation: [H⁺]=concentration if monoprotic [3]
32.
Apply your knowledge of Ka to this situation: pKa = −log Ka [3]