-16. A novel apparatus has been constructed that is both a hot plate and an anal

Question

-16. A novel apparatus has been constructed that is both a hot plate and an analytical balance to determine how the waters of hydra are driven off from a sample of a hydrate. In this experiment, a 0.822 g sample of copper sulfate pentahydrate is placed in arn evaporating dish that weighs 44.056 g. The hot plate is turned on to a setting of 2 (140°C) and data is recorded for mass as a funct f time as the water is driven off of the original sample. Each time that there is a level reading of mass for more than 2 minutes, th ists a stable compound. Identify the formula for each of the two stable compounds using the graph of the data below. For this problem, your work counts. You must prove what the formulas are based on calculations. Sorry, but no points for guessin Data from Experiment Picture of Hot Plate/Analytical Balance Mass v. Time for Cus04 5H20 on a Hot Plate/Scale 44.75 44.7 44.65 44.35 Time (min

Explanation / Answer

Ans: First we have to calculate the relative masses of all the Copper Sulphate.N.hydrate forms.

Let's make a table of observation

Initial mass of Cuvette = 44.056 g

Mass of sample, that has been taken = 0.822 g

Total mass at the beginning of experiment = 44.875g (Cuvette + sample)

Observations: smallest interval on the scale is 0.025g

Here we have observed two sets of masses.

S.no

Total mass (g)

(Cuvette + sample)

Mass of sample after heating (g)

1

44.775

0.719

2

44.575

0.519

We can have five more extra form of Copper sulphate with different masses

CuSO4.5H2O

249.68g

Relative ratio with pentahydrate

CuSO4.4H2O

231.68g

0.92

CuSO4.3H2O

213.68g

0.85

CuSO4.2H2O

195.68g

0.78

CuSO4.H2O

177.68g

0.71

CuSO4

159.68g

0.63

By simply comparing the ratio of masses of other form with starting material, we can conclude the stable phase obtained in the experiment.  

Obs 1. mass obtained/ actual mass taken = 0.719/0.822 = 0.87

Obs 2. mass obtained/ actual mass taken = 0.519/0.822 = 0.63

Hence from calculations, we can say that two most stable phases obtained belongs to CuSO4.3H2O and CuSO4.  

S.no

Total mass (g)

(Cuvette + sample)

Mass of sample after heating (g)

1

44.775

0.719

2

44.575

0.519

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

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