D) burning magnesium ribbon, as combustion is a chemical reaction so causes chemical change. The other 3 options do not involve reactions so there isn't a chemical change.
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:
Mean rate of reaction produced = 0.533 g/sec (approx.)
Explanation:
Given:
Reaction produced = 1.6 gram
Time taken = 30 sec
Find:
Mean rate of reaction produced
Computation:
Mean rate of reaction produced = Reaction produced / Time taken
Mean rate of reaction produced = 1.6 / 30
Mean rate of reaction produced = 0.533 g/sec (approx.)
Good grief, this stuff got caught in a black hole somewhere. It is terribly dense.
1 mL = 1 cc under normal conditions.
d = mass / volume
m = 20 kg
v = 5 mL
d = 20kg / 5 mL
d = 4 kg / mL
d = 4 kg / cc
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