12.00 moles of NaClO3 will produce how many grams of O2?

In a laboratory experiment, students synthesized a new compound and found that when 7.229 grams of the compound were dissolved i

STALIN [3.7K]

The question is incomplete, here is the complete question:

The common laboratory solvent chloroform is often used to purify substances dissolved in it. The vapor pressure of chloroform, CHCl₃, is 173.11 mm Hg at 25°C.

In a laboratory experiment, students synthesized a new compound and found that when 7.229 grams of the compound were dissolved in 207.8 grams of chloroform, the vapor pressure of the solution was 170.51 mm Hg. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight of this compound?

<u>Answer:</u> The molecular mass of the compound is 481.9 g/mol

<u>Explanation:</u>

The equation used to calculate relative lowering of vapor pressure follows:

$\frac{p^o-p_s}{p^o}=i\times \chi_{solute}$

where,

$\frac{p^o-p_s}{p^o}$ = relative lowering in vapor pressure

i = Van't Hoff factor = 1 (for non electrolytes)

$\chi_{solute}$ = mole fraction of solute = ?

$p^o$ = vapor pressure of pure chloroform = 173.11 mmHg

$p_s$ = vapor pressure of solution = 170.51 mmHg

Putting values in above equation, we get:

$\frac{173.11-170.51}{173.11}=1\times \chi_A\\\\\chi_A=0.0150$

This means that 0.0150 moles of compound is present in the solution

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of compound = 0.0150 moles

Given mass of compound = 7.229 g

Putting values in above equation, we get:

$0.0150mol=\frac{7.229g}{\text{Molar mass of compound}}\\\\\text{Molar mass of compound}=\frac{7.229g}{0.0150mol}=481.9g/mol$

Hence, the molecular mass of the compound is 481.9 g/mol

5 0

3 years ago

These organs make urine by removing waste and water from the blood. What organs are shown in the picturehese organs make urine b

Orlov [11]

Answer:

kidneys i think

Explanation:

because

3 0

3 years ago

Experiment #1A melting point of an old sample of Naphthalene was completed and a melting range of 77-83 oC was observed and reco

White raven [17]

Answer:

%error = 0.32%

Explanation:

Let's answer both questions, by parts.

1. Percentage error:

In this case, I do not have the video, but I do have the reported melting point of naphtalene which is 80.26 °C.

The expression to calculate the percentage error is the following:

%Error = absolute error / actual percentage. (1)

And the absolute error is:

Abs error = actual value - experimental value (2)

But the experimental value is a range, so we just have to get a average of that:

Exp value = 77 + 83 / 2 = 80 °C

Now the absolute error:

Abs error = 80.26 - 80 = 0.26 °C

Finally the %error:

%error = (0.26 / 80.26) * 100

<h2>%error = 0.32%</h2>

2. Meaning of melting point range and %error

The melting point range just means that the sample of naphtalene has impurities, and when a sample of any compound has impurities, melting point tends to be low. However, this decrease of temperature is a wider range. But usually a range of just 5° C means that compound has little traces of impurities but it can still be used for reactions.

The %error means that the impurities of the sample are really low, so the sample is practically pure with little traces of impurities.

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___ is the diffusion of water molecules across a

Gre4nikov [31]

I think the answer is osmosis

4 0

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In what way wax be harmful?

Lunna [17]

GEORGEOCTOBER 18, 2012Floor Wax is Harmful to the Environment

Floor wax is applied on floor surfaces to make it scuff-resistant, water-resistant, slip resistant and glossy. It provides a thin, protective and hard surface layer when applied to flooring. Conventional floor wax has five main ingredients and each one of them has detrimental effects on the environment, not to mention the chemical waste created by the continuous upkeep required. The cumulative effects of these ingredients on the environmental render their harmful actions more potent and difficult to reverse.

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3 years ago

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