Day 17 (chemistry)

Question 1

At what temperature does steam condense?

Answer 1

100 degrees celsius

Question 2

What name do we give to the solid that collects in a filter paper?

Answer 2

Residue

Question 3

What name do we give to the liquid that passes through a filter paper?

Answer 3

Filtrate

Question 4

In chromatography, what is the difference between a spot that travels a bigger distance up the paper and one which only moves a short distance?

Answer 4

The spot which travels further up the paper is more soluble in the solvent being used

Question 5

What term describes the highest point reached by the solvent on a chromatogram?

Answer 5

The solvent front

Question 6

Give the equation used to calculate an Rf value

Answer 6

Distance travelled by spot divided by distance travelled by solvent

Question 7

Give the lowest and highest possible values for any Rf value

Answer 7

0.00 and 1.00

Question 8

What should you use for drawing the baseline onto a chromatogram and why?

Answer 8

Pencil; graphite is insoluble so won’t run up the paper and may interfere with the results

Question 9

How deep into the solvent should you place the paper when starting a chromatography run?

Answer 9

The bottom of the paper must be under the solvent, but the baseline and spots must be above the solvent

Question 10

Define the term “atom”

Answer 10

The smallest particle of an element that is still recognisable as that element

Question 11

Define the term “atom”

Answer 11

The smallest particle of an element that is still recognisable as that element

Question 12

Define the term “molecule”

Answer 12

Two or more atoms chemically combined

Question 13

Give the mass and charge of a proton

Answer 13

1 and +1

Question 14

Give the mass and charge of a neutron

Answer 14

1 and 0

Question 15

Give the mass and charge of an electron

Answer 15

1/1840 and -1