Eduqas A-Level Chemistry A410QS
Formulae and Equations
Basic Ideas About Atoms
Chemical Calculations
Bonding
Solid Structures
The Periodic Table
Simple Equilibria and Acid-Base Reactions
Thermochemistry
Rates of Reaction
The Wider Impact of Chemistry
Organic Compounds
Hydrocarbons
Halogenoalkanes
Alcohols and Carboxylic Acids
Instrumental Analysis
Redox and Standard Electrode Potential
Redox Reactions
Chemistry of the P-Block
Chemistry of the D-Block Transition Metals
Chemical Kinetics
Enthalpy Changes for Solids and Solutions
Entropy and Feasibility of Reactions
Equilibrium Constants
Acid-Base Equilibria
Stereoisomerism
Aromaticity
Alcohols and Phenols
Aldehydes and Ketones
Carboxylic Acids and Their Derivatives
Amines
Amino Acids, Peptides and Proteins
Organic Synthesis and Analysis
Specified Practical Work
Practical Skills and Techniques
Mathematical Skills in Chemistry
Chemistry of the D-Block Transition Metals
Reactions of Cr³⁺, Fe²⁺, Fe³⁺ and Cu²⁺ with excess aqueous hydroxide
- 3 things to know
- Component 1
Overview
Recall questions on the precipitate formed by each of the four ions and its colour, which of them dissolves in excess hydroxide and why, the ionic equations, the darkening of the iron(II) precipitate in air, and using the pattern to identify an unknown ion.
What you need to know
Answer each one before you reveal it.
Write the ionic equation for the precipitation of chromium(III) hydroxide.
Describe what happens when aqueous sodium hydroxide is added to a chromium(III) solution until it is in excess.
Questions from this subtopic
Each one with the model answer underneath.
- 1
Describe what is seen when a small amount of aqueous sodium hydroxide is added to a solution containing Cr³⁺ ions.
Model answer
A green precipitate of chromium(III) hydroxide is formed.
- 2
Write the ionic equation for the precipitation of chromium(III) hydroxide.
Model answer
Cr³⁺(aq) + 3OH⁻(aq) → Cr(OH)₃(s).
- 3
Describe what happens when aqueous sodium hydroxide is added to a chromium(III) solution until it is in excess.
Model answer
The green precipitate dissolves to give a green solution containing the [Cr(OH)₆]³⁻ ion.
- 4
What does the behaviour of chromium(III) hydroxide in excess alkali show about it?
Model answer
It shows that chromium(III) hydroxide is amphoteric.
- 5
Describe what is seen when aqueous sodium hydroxide is added to a solution containing Fe²⁺ ions.
Model answer
A green precipitate of iron(II) hydroxide is formed.
- 6
Write the ionic equation for the precipitation of iron(II) hydroxide.
Model answer
Fe²⁺(aq) + 2OH⁻(aq) → Fe(OH)₂(s).
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Chemistry of the D-Block Transition Metals, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.