Analytical Flashcards
What is a precipitate in chemistry?
An insoluble solid product that forms when two solutions react
Precipitates are often used in qualitative analysis to identify the presence of specific ions in a solution.
Why is the colour of a precipitate important in analytical chemistry?
It helps identify the metal cation present in the solution
Different metal cations produce precipitates of various colours, aiding in their identification.
What happens when sodium hydroxide (NaOH) is added to a solution containing metal cations?
Metal hydroxides typically precipitate out, forming solid precipitates with characteristic colours
This is a common method to test for the presence of specific metal ions.
Which two metal hydroxides do not dissolve in excess NaOH?
Calcium hydroxide (Ca(OH)₂) and magnesium hydroxide (Mg(OH)₂)
These metal hydroxides can be used for specific tests in analytical chemistry.
What are the precipitate colours for transition metal hydroxides with NaOH?
Copper(II) hydroxide: Blue
Iron(II) hydroxide: Green
Iron(III) hydroxide: Orange-brown
The colour of the precipitate can indicate the specific transition metal present.
What is the flame test used for?
To identify metal ions by the colour they produce when heated in a flame
Each metal ion emits a specific wavelength of light, producing a unique colour.
What gas is released when a metal reacts with an acid?
Hydrogen gas
This reaction is a common demonstration of acid-metal reactions in chemistry.
What happens when chlorine is added to potassium bromide solution?
The solution turns orange as bromine is formed
This is an example of a halogen displacement reaction.
What happens when chlorine is added to potassium iodide solution?
The solution turns brown as iodine is formed
This reaction also demonstrates the reactivity of halogens.
What happens when bromine is added to potassium iodide solution?
The solution turns brown as iodine is formed
This shows that bromine can oxidize iodide ions to iodine.
What is the general equation for the reaction between an acid and a base?
Acid + Base → Salt + Water
This is a fundamental reaction in acid-base chemistry.
What is the general equation for the reaction between an acid and a metal carbonate?
Acid + Metal Carbonate → Salt + Water + Carbon Dioxide
This reaction is commonly used in laboratory settings to produce carbon dioxide.
What is the general equation for the reaction between a metal and an acid?
Metal + Acid → Salt + Hydrogen
This shows how metals react with acids to produce hydrogen gas.
How do you name a salt?
The first part comes from the metal or compound used, and the second part comes from the acid
Example: Sulfuric acid reacting with magnesium forms magnesium sulfate.
