Stoichiometry and the Mole

Question 1

What is an Experimental Error?

Answer 1

The Experimental error is the uncertainty obtained in a measurement

Question 2

What are Systematic Errors?

Answer 2

Systematic errors arise from flaws in equipment or investigation design.

Reproducible with precision

Can be identified and corrected

Question 3

Examples of Systematic Errors?

Answer 3

Typical causes of systematic error include
Observational error

Imperfect instrument calibration

Environmental interference.

Forgetting to tare or zero a balance produces mass measurements that are always “off” by the same amount

Question 4

What are Random Errors?

Answer 4

Random errors are errors that cannot be avoided and are always present

They Arise from variations in how a student or students record a measurement

Question 5

How to detect Systematic Errors?

Answer 5

• Analyse samples of known composition
• Analyse ‘blank’ samples and verify that the instrument will give a zero result
• Obtain results for a sample using multiple instruments to verify the accuracy of the instrument

Question 6

What is Hydrogen Carbonate?

Answer 6

HCO3-

Question 7

What is Phosphate?

Answer 7

PO4 3-

Question 8

Metal + Water

Answer 8

Metal Hydroxide + Hydrogen

Question 9

Oxide + Acid

Answer 9

Salt + Water

Question 10

Hydroxide + Acid

Answer 10

Salt + Water

Question 11

Carbonate + Acid

Answer 11

Salt + Water + Co2

Question 12

Hydrogen carbonate + acid

Answer 12

Salt + Water + Co2

Question 13

Ammonia + Acid

Answer 13

Ammonium Salt

Question 14

Metal Carbonate

Answer 14

Metal Oxide + Co2

Question 15

Solubility Rules?

Answer 15

N- itrates
A-cetues
G-roup 1
S-ulfates (Castro Bear + PMS)
A-mmonium
G-roup 17 PMS

Question 16

Give three reasons why the amount of X is less than the maximum theoretical yield?

Answer 16

Reversible, Product lost on Isolation, Other Reactions take place, Reaction hasn’t fully finished

Question 17

1 tonne in g?

Answer 17

1000000

Question 18

How to convert MPa into Pa?

Answer 18

MPa x 1000000 = Pa

Question 19

How to convert dm3 into m3?

Answer 19

dm3/1000 = m3

Question 20

Suggest why there may be a higher mass of mercury?

Answer 20

The oxide may contain some mercury