A substance that contains only one type of compound or element throughout i

2 more elements chemically bonded together 

A chemically pure substance melts/boils at a specific temperature. The closer the measured value is to the melting/boiling point, the purer it is. 

How can melting/boiling points be used to distinguish pure/impure substances? 

Useful mixtures with a precise purpose which are made by following a formula 

It’s the ratio between the distance travelled by the dissolved substance and the distance travelled by the substance. Work it out by diving substance distance by solvent distance. 

What is an RF value? How can you calculate it? 

Pencil lines on top and bottom.  Mark points equal distances on the baseline. Put one drop of ink on each point. Add a little bit of water so it just touches the bottom of the paper. Wait for substances to travel across the paper. Take out and dry. Calculate the RF value.

A lighted splint in hydrogen will result in a squeaky pop

What colour flame would Lithium produce? 

What colour flame would potassium produce? 

What colour flame would Calcium produce? 

It would produce a white precipitate. (Colourless in excess)

Using sodium hydroxide, how would you identify Aluminium? 

Using sodium hydroxide, how would you identify Iron (III) ? 

Using sodium hydroxide, how would you identify calcium? 

Using sodium hydroxide, how would you identify Magnesium? 

Using sodium hydroxide, how would you identify Copper (II) ? 

Using sodium hydroxide, how would you identify Iron (II) ? 

Do the limewater test. It will turn cloudy if carbon dioxide is present which means the substance would be a carbonate 

How can dilute acids be used to identify carbonates?

Bromine - cream precipitate. Chlorine - white precipitate.       Iodine - yellow precipitate.

Hiw can silver nitrate be used to identify halides?

How can barium chloride, in the presence of HCl be used to identify sulfate ions?

Quicker, more accurate and very sensitive (can detect even the smallest amount) 

What are the advantages of instrumental methods compared to chemical tests? 

More expensive, destructive, only identifies elements and not compounds 

What are the disadvantages of using instrumental methods compared to chemical tests? 

Samole is injected in a flame. Ions heat up - elections become excited. When they drop back to their original levels, they transfer energy as light. Light is sent through a prism. Seperate wavelengths are recorded by a detector. Each ion will produce a different pattern of wavelengths  

Chemical Analysis - GCSE Chemistry

Flashcards

Chemical Analysis - GCSE Chemistry

Chemistry Paper 1 Knowledge Recall

GCSE AQA Chemistry paper 2

atoms (protons, neutrons & electrons)

year 8 chem flashcards /questions