Amount Of A Substance

Question 1

What is a mole

Answer 1

mole is the amount of substance in grams that has the same number of particles as there are atoms in 12 grams of carbon-12

Question 2

Relative atomic mass

Answer 2

is the average mass of one atom compared to one twelfth of the mass of one atom of carbon-12

Question 3

Relative molecular mass

Answer 3

is the average mass of a molecule compared to one twelfth of the mass of one atom of carbon-12

Question 4

1cm^3

Answer 4

1g or 1ml

Question 5

Why is a volumetric pipette more accurate than a measuring cylinder

Answer 5

It has a smaller uncertainty

Question 6

Diluting a solution will..

Answer 6

• not change the amount of moles of solute present
• increase the volume of solution and hence the concentration will lower

Question 7

Potential errors using a gas syringe

Answer 7

• gas escapes before bung inserted
• syringe sticks
• some gases like carbon dioxide or sulfur dioxide are soluble in water so the true amount of gas isn’t measured

Question 8

Do u use balancing numbers in atom economy

Answer 8

Yeah

Question 9

To reduce the uncertainty of butette readings..

Answer 9

• increase conc and volume of substance in the conical flask
• decrease conc of substance in the burette

-> this gives us a larger titre