SC14c Concentrations

Question 1

finding concentration of salt in sea water? practical

Answer 1

~Record the mass of a dry evaporating basin.​
~Measure 20 cm3 of the sea water and add it to the evaporating basin.​
~Heat the evaporating basin and sea water. Stop heating when crystals start to form. ​
~Allow the basin and solid to cool (and, if possible, leave to dry overnight).​
~Record the mass of the evaporating basin and salt.​

Question 2

finding concentration of salt in sea water? calculate

Answer 2

~the mass of salt obtained from 20 cm3 of sea water​
~the concentration of salt in the sea water in gdm-3​
~the concentration of salt in the sea water in moldm-3 (assume all the salt in the seawater sample is NaCl)​​

Question 3

concentration (g dm-3) =

Answer 3

concentration (mol dm-3) x Mr

Question 4

mass (g) =

Answer 4

concentration (g dm-3) x volume (dm3)
or
Mr x mole