rp3 producing a dilution series

Question 1

point of rp3

Answer 1

produce a dilution series of a solute
to produce a calibration curve to identify wp of plant tissue

Question 2

how to calculate dilutions

Answer 2

C1 x V1 = C2 x V2
c1 - conc of stock solution
v1 volume of stock solution used to make new concentration
c2- conc of solution your making
v2 = volume of new solution your making

Question 3

method to produce calibration curve to identify wp of plant tissue

Answer 3

create dilution series 1moldm sucrose solution (0.0,0.2,0.4,0.6,0.8,1) MAKE SURE VOLUME KEPT SAME
use scalpel to cut potato into identical cylinders
MAKE SURE SIZE/SHAPE/SA/AGE same
blot dry with paper towel to remove excess water b4 weighing-record initial mass
immerse one chip in each solution leave for set time in water bath at 30c MAKE SURE TEMP AND LENGTH OF TIME SAME
blot dry with paper towel measure final mass

Question 4

processing the data

Answer 4

calculate % change in mass
plot graph - conc on x and %change on y
wp of sucrose solution = wp of potato cells

Question 5

why calculate %change in mass

Answer 5

enables comparison
as plant tissues samples had differential masses

Question 6

why blot dry before weighing

Answer 6

solution on surface adds to mass
and amount of solution on cube varies

Question 7

increase in mass meaning

Answer 7

water moves into cells by osmosis
wp of solution higher than inside cells

Question 8

decrease in mass meaning

Answer 8

water moved out of cells by osmosis
wp of solution lower than inside cells

Question 9

no change in mass

Answer 9

no net gain or loos of water by osmosis