Answer: 2.8 moles of copper (Il) sulfide
will be produced from 2.8 moles of sulphur.
Explanation:
The balanced chemical reaction is:
According to stoichiometry :
1 mole of
produce = 1 mole of copper (Il) sulfide
Thus 2.8 moles of
will produce=
of copper (Il) sulfide 
Thus 2.8 moles of copper (Il) sulfide
will be produced from 2.8 moles of sulphur.
The answer would be C.
The salt and the water have both undergone physical changes.
Hope this helps!
Answer:
The answer is D. 0.60 L
Explanation:
The balanced reaction equation including states of matter is;
H₂SO₄(aq) + 2NaOH(aq) → Na₂SO₄(aq) + 2H₂O(l)
More simple:
H2SO4 + 2NaOH → Na2SO4 + 2H2O
Now, we can see from this reaction equation that the mole ratio of NaOH to H2SO4 is 2:1
Number of moles of H2SO4 reacted = 1.2 moles
Hence;
2 moles of NaOH reacts with 1 mole of H2SO4
x moles of NaOH reacts with 1.2 moles of H2SO4
x = 2 * 1.2/1 = 2.4 moles of NaOH
Recall that;
Number of moles = Concentration * Volume
Volume = number of moles/concentration
Volume of NaOH is obtained from;
Volume = 2.4 moles/ 4.0 M
Volume = 0.60 L