You have a solution suspected to contain copper(II) ions, barium ions, or iron ions. Which of the following solutions might be added to determine which cation is present?

(A) ammonium nitrate
(B) potassium sulfate
(C) sodium acetate
(D) sodium chloride
(E) zinc bromide

potassium sulfate

Explanation:

To determine the cation present, a reagent is added which is able to precipitate one of the suspected cations. This will confirm the presence of that cation or disprove it all together. It is known that sulphates of group 2 elements are insoluble in water. When potassium sulfate is added, barium sulphate will be removed from solution as a white precipitate thus confirming that the solution contains barium ions.

a. hope i'm right

explanation:

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.