i just cant understand the question
please take a clear pic
Answer:
63.86 mg
Explanation:
Molar mass is the mass of 1 mol of compound / atom.
molar mass of the compound is - 310 g/mol
mass of 1 mol is - 310 g
therefore mass of 2.06 x 10⁻⁴ mol is - 310 g/mol x 2.06 x 10⁻⁴ mol = 0.06386 g
mass of calcium phosphate is - 63.86 mg
Atomic size decreases along a period because of the nuclear charge increasing, this means that the electrons are more attracted to the nucleus, which decreases the size.
Atomic size increases down a group because the number of electron shells is greater each time, meaning that the electrons are less attracted to the nucleus.
Explanation:
a) The presence of sulfate ions in a solution can be confirmed by the reaction of barium chloride in an acidic medium.
The balanced chemical equation of the reaction is shown below:
Hence, the white precipitate is barium sulfate and its formation with the ionic equation is shown below:
b) The presence of copper (II) ions can be confirmed by the following test:
Add potassium iodide solution to copper (II) solution.
Then a white ppt of cuprous iodide along with the liberation of iodine is observed and the entire solution attains brown color.
The chemical equation of the reaction is shown below:
c)(i)Due to this reaction, the blue color of the solution becomes white.
Reddish-brown copper is deposited at the bottom of the container.
(ii)In this reaction, zinc is oxidized.
d) (i) Copper is produced at the cathode.
(ii)
(iii) The reaction that takes place at the cathode is reduction.
Reduction is gaining of electrons.