Please help me answer part 3, the analysis part of this question. Trial 3 is not

Question

Please help me answer part 3, the analysis part of this question. Trial 3 is not needed.

Mass of copper and chlorine compound in 1.00 mL of solution Mass Measurements Weighing paper Weighing paper plus zinc before rxn Evaporating dish #1 Evaporating dish #1 plus zinc after rxn Evaporating dish #2 Evaporating dish #2 plus copper (1^nd) Evaporating dish #2 plus copper (2^nd) Evaporating dish #2 plus copper (3^rd) Evaporating dish #2 plus copper (4^th) Analysis Mass of Cu and Cl cmpd (1 times 25.0 mL) (25.0 mL of the solution was used in Procedure step 2) Mass of reactant Zn (2b - 2a) Mass of Zn remain (2d - 2c) Mass of Zn consumed (3b - 3c) Mass of Cu (2g or 2h or 2i - 2e) Mass of Cl (3a - 3e) Mass % Cu (3e/3a) times 100% Mass % Cl (3f/3a) times 100% Moles of Zn consumed (3d/AW_zn) Moles of Cu (3e/AW_cu) Moles of Cl (3f/AW_cl) Empirical formula (Use 3j and 3k in step 3 of example calculation)

Explanation / Answer

3.(a) mass = Molarity × Volume (25mL of the soln is used)

= .081g/mL × 25mL = 2.025g

(b) Mass of reactant Zn: (2b-2a)

Weighing paper plus zinc before reaction - weighing paper

Trial 1:

1.752g-0.417g = 1.335g

Trial 2:

2.190g-0.417g = 2.043g

(c). Mass of Zn remain = Evaporating dish 1 with Zn remain-evaporating dish 1 (2d-2c)

Trial 1:

93.498g-90.909g =2.589g

Trial 2:

92.452g-90.909g = 1.543g

(d).Mass of Zn consumed : (3b-3c)

= Mass of reactant Zn - Mass of Zn remain

Trial 1:

1.335g-2.589g = -1.254g (can not be negative,something wrong with your reading) if not,this reading should be discarded.

Trial 2:

2.043g-1.543g =0.5g

(e).Mass of Cu = evaporating dish 2 plus copper - evaporating dish 2 (2g-2e)

Trial 1:

91.500g-90.909g = 0.501g

Trial 2:

91.150g-90.909g =0.241g

(f) Mass.of Cl:   

Mass.of Cu and Cl compound - Mass of Cu(3a-3e):

Trial 1:

2.025g-0.501g = 1.524g

Trial 2:

2.025g-0.241g =1.784g

(g) Mass % Cu:

(Mass of Cu/Mass of Cu and Cl)×100 (3e/3a)×100%:

Trial 1:

0.501g/2.025g ×100 =24.74%

Trial 2:

0.241g/2.025g × 100 = 11.90%

(h) Mass % Cl: (3f/3a)×100

Mass of Cl/Mass of Cu and Cl × 100:

Trial 1:

1.524/2.025 × 100 = 75.26%

Trial 2:

1.784/2.025 × 100 = 88.09%

(i) Moles.of Zn consumed : (3d/AW)

Atomic weight of Zn = 65.38g/mol:

Trial 1: Negative Reading

Trial 2:

0.5/65.38 = 0.0141mol

(j) Moles of Cu(3e/AW):

Atomic weight of copper = 63.55g/mol

Trial 1:

0.501/63.55 = 0.0079mol

Trial 2:

0.241/63.55 =0.0038mol

(k) Moles of Cl(3f/AW):

Atomic weight of Cl = 35.45

Trial 1:

1.524/35.45=0.0430mol

Trial 2:

1.784/35.45 = 0.0503 mol

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