Posted: December 17th, 2016

To make up the weaker solutions, what volume of the 80 uM nickel solution and what volume of nutrient solution should you add together to make a) 1 litre of 20 uM nickel solution?

30 Plants were first grown for 2 weeks, each in its own universal tube which contained 25 ml of nutrient solution. After 2 weeks each of the 30 individuals was replaced in a new tube containing 25 ml of nutrient solution to which NiCl2 had been added at the concentrations of 0, 0.5, 5, 20, or 80 uM. Six plants were grown at each nickel concentration. The plants had to be split between three racks, each of which was only capable of holding 10 plants in a 5 x 2 grid (see below).

(Atomic weight of Ni = 58.7. Atomic weight of Cl = 35.5. Atomic weight of O = 16, Atomic weight of H = 1)

1) You are supplied with solid hydrated nickel chloride which has the formula NiCl2 6H2O. What mass of this should you dissolve in 1 litre of nutrient solution to make an 80 uM nickel stock solution?

2) To make up the weaker solutions, what volume of the 80 uM nickel solution and what volume of nutrient solution should you add together to make

a) 1 litre of 20 uM nickel solution?

b) 1 litre of 5 uM nickel solution?

c) 1 litre of 0.5 uM nickel solution?