Answer: C) To monitor weather event restricted several days in advance.
Explanation:
The answer can be explained when you burn something cleanly (with a very hot item) or not. With a candle lots of Carbon dioxide is producted but when using a bunson burner hardly any CO2 is produced.
As I understand from your question, we should synthesize nickel sulfate first from nickel (II) oxide and sulfuric acid and second from nickel carbonate and sulfuric acid.
The chemical reactions will look like this:
NiO (s) + H₂SO₄ (aq) → NiSO₄ (aq) + H₂O (l)
NiCO₃ (aq)* + H₂SO₄ → NiSO₄ (aq) + H₂CO₃ (aq)
but carbonic acid will decompose to carbon dioxide and water
H₂CO₃ (aq) → CO₂ (g) + H₂O (l)
(*) NiCO₃ has a poor solubility in water, but enough to start the reaction.
Answer:
Density of the copper = 8.94g/cm^3
Student A results = 7.3gm/cm^3 ,9.4 gm/cm^3 , 8.3gm/cm^3
Student B results = 8.4 gm/cm^3 , 8.8 gm/cm^3 , 8gm/cm^3
From the observations we conclude that
Student A's result is accurate but not precise as the trials noted are not close to each other.
Student B's result is accurate and precise as the trials noted are close to each other.
Mean density of student A = 7.3 + 9.4 + 8.3 /3 = 8.33gm/cm^3
Mean density of student B = 8.4 + 8.8 + 8 /3 = 8.4 gm/cm^3
both the densities of A and B are 0.5 away from the actual density.
