Science - Chemistry - Quantitative Chemistry - Concentrations - C3b

Question 1

what is concentration

Answer 1

the amount of substance in a certain volume of solution

Question 2

if there’s more solute that is in a volume, does the concentration increase or decrease ?

Answer 2

the concentration increases

Question 3

how do you calculate the concentration ?

Answer 3

mass of solute (g) / volume of solution (dm3)

Question 4

how can you work out how uncertain your measurements are when doing an experiment ?

Answer 4

repeat the experiment and create a mean result, the range of the results tells you how uncertain the measurements are, the greater the range, the more uncertain

Question 5

how do you calculate the concentration in moles ?

Answer 5

amount of solute (mol) / volume of solution (dm3)

Question 6

how do you convert a concentration from g/dm3 to mol/dm3 ?

Answer 6

concentration (g/dm3) / Mr

Question 7

how do you step by step, calculate concentrations in moles per dm3 ?

Answer 7

1. work out how many moles of the ‘known’ substance you have using the formula :
   number of moles = concentration (mol/dm3) x volume (dm3)
2. write down the balanced equation of the reaction and work out how many moles of the ‘unknown’ substance you must have had
3. work out the unknown concentration using the formula:
   concentration(mol/dm3) = number of moles/volume (dm3)

Question 8

how do you calculate concentrations in grams per dm3 ?

Answer 8

concentration (mol / dm3) x Mr