Chem Flashcards
Compounds
2 or more substances that are chemically combined, have a fixed ratio and turns in to a new substance so it has new properties
Mixtures
2 or more substances that mixed but not chemically combined,they don’t have a fixed ratio and they keep the properties of the induvidual substances
What are the 2 substances called in a mixture?
Components
Alloys
A mixture of elements and at least on of them is a metal
An example of an alloy
Brass - copper and zinc, Bronze - copper and tin, Steel - iron and carbon and sometimes chromium and nickel
How is mineral water a mixture?
The minerals are dissolved in it and can be separated. It is also a solution
Name different types of ways to separate mixtures.
Sieving, using a magnet, evaporation, filtration, distillation
Sieving
When we use a sieve to separate 2 solid components one big and one small. The bigger particles are left on the sieve
Using a magnet
When one of the components is magnetic e.g. iron and sulfur
Evaporation
When we have a soluble solid dissolved in a liquid so we heat it
Filtration
When we have an insoluble solid with a liquid we use a funnel, filter paper, and a beaker. The component left on the filter paper is called a residue and the component in the beaker is called a filtrate
Chromatography
a method used to separate mixtures of dissolved chemicals
Why do we use chromatography?
To study the dyes used in food and since black has more than one colour, chromatography will work very well
Distillation
When we have 2 liquids, we heat the mixture and it goes down then we use a condenser with cold water to condense the hot water and the liquid gets sent to the beaker
How can you do paper chromatography?
When we have chromatography paper we make a baseline and draw a dot with black ink. We use a beaker with water not above the black dot and slowly the colours will start to separate
Chromatogram
The resulting paper with all of the colurs
What are the last colours on the chromatogram?
The primary colours
Capillary action
When the chromatography paper has tubes that the water molecules go though and it moves upwards
Why do we use black ink?
Because it is a mixture of colours
An example of ink that doesn’t dissolve in water
A permanent marker pen needs alcohol to dissolve it
Solution
A mixture in which particles (solute) are mixed with particles of a liquid so that the substance can no longer be seen
Solute
A substance that is dissolved
Solvent
A liquid that substances dissolve in
When a solute disappears in a solvent, what is it called?
Dissolving
Is a solution a mixture or compound?
A mixture because it can be separated by evaporation
Why is milk not a solution?
Because the particles did not completely disappear
Conservation of mass
When there is no loss or gain of mass in a solution
What is a concentrated solution?
A solution that has more solute particles than solvent and a higher concentration of solute dissolved
What is a dilute solution?
A solution that has less solute particles than solvent and a low concentration of solute dissolved
Soluble
When a solute can dissolve in a solvent
Insoluble
When a solute can’t dissolve in a solvent
What is a saturated solution?
When we have the maximum amount of solute in a solvent and the solute can be seen at the bottom of the solution
What is a unsaturated solution?
When we don’t have the maximum amount of solute in a solvent
Solubility
The amount of solute that can dissolve in a certain amount (usually 100g) of solvent at a given temperature and pressure to produce a saturated solution
What are the factors that affect solubility?
Temperature- The higher the temperature of the solvent, the faster the solute will dissolve
Shaking/stirring- Shaking (agitation) cause solids to dissolve faster
Particle size- smaller particles dissolve faster because they have more surface area
What is something that doesn’t increase the rate of dissolving?
Increasing the amount of solute
What are variables?
Things that could affect the results of an experiment
Independent variable
The variable that you will change
Dependent variable
The variable that you will measure
Control variable
The variable that you will keep the same
Where do the independent and dependent variable go on a graph?
The independent variable- horizontal axis
The dependent variable- vertical axis
