Today you\'ll be performing a sequence of reactions - what are the initial start

Question

Today you'll be performing a sequence of reactions - what are the initial starting materials for the sequence, and what are the final products of the entire sequence? (Note that we'll be using zinc for the reduction of Cu(II), not aluminum). Why is it not essential to record the exact amount of NaOH added to the copper (II) solution? How will you separate CuO from its solution today? In your own words, what does "decant" mean? What gas is produced when the solid zinc is added to the sulfuric acid solution? Why is it suggested to do this step in the hood? If 3.91 g of Cu(NO_3)_2 are obtained from allowing 1.98 g of Cu to react with excess HNO_3, what is the percent yield of the reaction?

Explanation / Answer

Q1.

Initially:

Solid Zinc, solution of Copper

After reaction

Aquoeuos Zinc, Zn +2, and solid Copper Cu(s)

Q2.

No need to recor NaOH, since it will not interfere with the total amount of Copper... As well ass we disolve ALL of copper

Q3.

CuO --> will be solid, either filter or decant

decant means gettin all the liquid exces on the top, in order to facilitate separation

Q4.

The gas produced:

Zn(s) + H2SO4(aq) --> H2(g) + ZnSO4(aq)

Hydrogen gas is produced

It is flammable, and pungent oder, follow safety rules and do this in th hood

Q5.

m = 3.91 g of Cu(NO3)2

m = 1.98 g of Copper

find % yield

mol of Copper initially = mass/MW = 1.98/63.5 = 0.03118

mol of Copper finally = mass/MW = (3.91)/187.56 = 0.02084

so

% yield = real / theoretical * 100% = 0.02084/0.03118*100 =66.837 %

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.