amount of substance

Question 1

What is relative atomic mass - Ar

Answer 1

Relative atomic mass = average mass of one atom of an element / 1/12th the mass of a c12 atom

Question 2

What is the relative molecular mass - Mr

Answer 2

Relative molecular mass = average mass of one molecule / 1/12th the mass of a C12 atom

Question 3

What is the avogardo constant

Answer 3

Is the number of atom in 12g of C12

Question 4

How do you calculate the number of particles

Answer 4

Number of particles = moles x avogadro constant

Question 5

What is the yield equation

Answer 5

% yield = amount of specific product formed / theoretical maximum amount of products that could be formed x 100

Question 6

What is the moles equation

Answer 6

Moles = mass / molecular mass

Question 7

What is the atom economy equation

Answer 7

% atom economy = mass of desired products / total mass of reactants x100

Question 8

Concentration equation

Answer 8

Concentration (m dm-3) = moles / volume (dm3)

Question 9

What is the equation for ideal gas

Answer 9

PV = NRT

Question 10

Rearrange the ideal gas equation to get p

Answer 10

P = NRT/V

Question 11

Rearrange the ideal gas equation to get v

Answer 11

V = NRT / P

Question 12

Rearrange the ideal gas equation to get n

Answer 12

N = PV/ RT

Question 13

Rearrange the ideal gas equation to get t

Answer 13

T = PV/ NR

Question 14

Percentage error equation

Answer 14

% error = uncertainty in equipment/ measurement x 100

Question 15

What are the steps on how to make a standard solution

Answer 15

Step 1 - transfers known mass of solid
Add sample to weighing boat and record
Mass using 2 decimal places balance
Transfer sample to beaker and reweigh empty boat
Record difference in mass

Step 2 - dissolve in water
Add diluted deionised ? Water
Stir (with a glass rod) or swirl
Until solid has dissolved

Step 3 - transfer, washing and agitation
Transfer to volumetric/ graduated flask using a funnel with washings
Make up to 250cm3 / mark with water
Shakes/ invert / mixes