Which of the following pair of substances can
be used to prepare copper(ii) nitrate in the
laboratory?

a) copper(ii) oxide and nitric acid

b) copper(ii) sulphate and nitric acid

c) copper(ii) chloride and potassium nitrate

d)copper(ii) carbonate and ammonium
nitrate

Jenny places a strip of ph paper into a solution. when she removes the ph paper, it has turned yellow-green. what should jenny do next to determine the ph of her solution? a. use a different testing method because the ph paper should not change colors b. place the ph paper into a machine that reads the ph of the solution c. compare the ph paper's color with the color of ph paper from another solution d. compare the ph paper's color with a chart of colors and ph ranges