Cobalt has an atomic number of 27 and atomic mass of 59. How many neutrons does cobalt have?

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?

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

Explanation:

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

Which of the following molecules or ions is polar? (20 POINTS)

inessss [21]

Answer:

All of these three are polar molecules or ions

Explanation:

1) CO3 ^2-

It is a polar ion because it consists of one Oxygen atom and three carbon atoms so there is a substantial electroegativity difference between carbon and Oxygen due to which shared electrons are attracted more towards Oxygen creating partial negative charge on it and less towards carbon creating a partial positive charge on it, which makes the overall ion polar.

2) HCN

HCN is a polar molecule because there is substantial electronegativity difference between Carbon and Hydrogen as well as between Carbon and Nitrogen. Due to this negative charge is induced over Nitrogen because electronegativity of Nitrogen is 3.0 and positive charge on Carbon because its electronegativity is 2.5. The overall molecule is polar.

3) NO3^-1

Nitrate ion is also a polar molecule because there are three atoms of Oxygen and one atom of Nitrogen. There is substantial electronegativity difference between oxygen (3.44) and nitrogen (3.0) due to which partial positive charge is created on Nitrogen and partial negative charge created over three Oxygen atoms. The overall molecule is polar.

Hope it helps!

8 0

4 years ago

Which law states that, in chemical reactions, the total mass of reactants must equal the total mass of the products?

WARRIOR [948]

Answer:

Conservation of mass

Explanation:

The Conservation of mass states that.

8 0

3 years ago

Based on the given description which is most likely a mixture

suter [353]

Answer:

what descriptions

Explanation:

6 0

3 years ago

How does solar radiation affect the thermosphere? God bless all! :)

DENIUS [597]

Answer:

Thermospheric temperatures increase with altitude due to absorption of highly energetic solar radiation. ... Radiation causes the atmosphere particles in this layer to become electrically charged particles, enabling radio waves to be refracted and thus be received beyond the horizon.

Explanation:

5 0

3 years ago

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Cobalt has an atomic number of 27 and atomic mass of 59. How many neutrons does cobalt have? ￼

Cobalt has an atomic number of 27 and atomic mass of 59. How many neutrons does cobalt have?