In a gravimetric analysis of a soluble Chloride use the massescalculations in bo

Question

In a gravimetric analysis of a soluble Chloride

use the massescalculations in bold.

This is just the mass of the cruicible, use the masses in bold.

Crucible Number

Mass of Crucible

First Trial

Mass of Crucible

Second Trial

Mass of Crucible

Third Trial

1

32.6083 grams

32.6083 grams

N/A

2

33.0459 grams

33.0454 grams

33.0454 grams

3

32.4665 grams

32.4664 grams

N/A

This table indicates the mass of the unknown sample placed in each beaker.

Beaker number

Mass of Unknown sample

1

0.2024

2

0.1996

3

0.2032

After weighing the precipitate

Crucible Number

Mass of Crucible 1sttrail

Mass of Crucible 2ndtrail

Mass of Crucible 3rdtrail

Mass of Crucible 4thtrail

Mass of Crucible 5thtrail

1

33.0913 (g)

33.0953 (g)

33.0943 (g)

33.0941 (g)

N/A

2

33.5250 (g)

33.5287 (g)

33.5275 (g)

33.5273 (g)

N/A

3

32.9453 (g)

32.9573 (g)

32.9578 (g)

33.9564 (g)

32.9565 (g)

Calculate:

A.) Mean Percent chloride in the unknown

B.) Standard Deviation

C.) 95% confidence level

Show all work please.

Crucible Number

Mass of Crucible

First Trial

Mass of Crucible

Second Trial

Mass of Crucible

Third Trial

1

32.6083 grams

32.6083 grams

N/A

2

33.0459 grams

33.0454 grams

33.0454 grams

3

32.4665 grams

32.4664 grams

N/A

Explanation / Answer

From the above shown data

Mass of NaCl = mass of crucible + substnace (IIIrd table) - Mass of crucible (Ist table)

Trial 1 : Mass of NaCl = 33.0941 - 32.6083 = 0.4858 g

Trial 2 : Mass of NaCl = 33.5273 - 33.0454 = 0.4819 g

Trial 3 : Mass of NaCl = 33.9565 - 32.4664 = 1.4901 g

Mean NaCl = 0.8193 g

A) Mean percent chloride = 81.93 %

B) standard deviation = sq.rt.(sum(x-mean)^2/3)

= sq.rt.(0.2250) = 0.4743

C) 95% confidence level = 0.28 to 1.36

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

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