chemical analysis

Question 1

what is volumetric analysis ?

Answer 1

involves using a solution of accurately known concentration called a standard solution, in a quantitative reaction to determine the concentration of another substance.

Question 2

what is a titration used to determine?

Answer 2

the volumes of solution required to reach the end point of a chemical reaction.

Question 3

what is an indicator used for ?

Answer 3

to show when the end point of a reaction is reached.

Question 4

titre volumes within 0.2cm of each ther are known as…

Answer 4

concoordant

Question 5

how do you make a standard solution (solution of accurately known concentration) ?

Answer 5

mass of compound must be accurately weighed out and dissolved in a small volume of distilled water then transferred to a volumetric flask. Finally the solution is made up to the mark on the flask with distilled water and the flask is inverted several times to mix.

Question 6

what is chromatography ?

Answer 6

a technique used to separate the components present within a mixture.

Question 7

RF value (distance travelled by sample)…

Answer 7

1. larger molecules have a smaller RF value as they will travel slower up the chromatography paper.
2. polar molecules will have higher RF values in polar solvents. (the more soluble the solute is in the mobile phase the shorter the time it will take to travel)

Question 8

the main pieces of information that can be gathered from a gas chromatography are…

Answer 8

1. the number of compounds in the mixture represented by the number of peaks.
2. how much of each compound is present represented by the height of the peak.
3. the retention time indicated by the position of the peak.

Question 9

what does it mean if a gas chromatography goes off of the page and what can be done about this ?

Answer 9

the sample is too concentrated and must be diluted.