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4 years ago

I have to write a report (below) could someone start me off?

Chemistry

1 answer:

sergey [27]4 years ago

3 0

Answer:

In everyday use, "theory" frequently implies an untested hunch, or a supposition without supporting proof. For scientists, a theory has about the contrary significance. A hypothesis is a very much validated clarification of am aspect of the natural world that can join laws, speculations and realities.

Explanation:

I hope this helps!

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At a certain temperature, the solubility of N2 gas in water at 2.38atm is 56.0mg of N2 gas/100 g water . Calculate the solubilit

KonstantinChe [14]

Answer: The molar solubility of nitrogen gas when pressure is increased is 0.042 mol/L

Explanation:

We are given:

Solubility of nitrogen gas in water = 56.0 mg/100 g

Or, solubility of nitrogen gas in water = 0.056 g/100 mL (Density of water = 1 g/mL & Conversion factor used: 1 g = 1000 mg)

Solubility of a solute is defined as the moles of solute dissolved in 1 L of solvent.

Conversion factor used: 1 L = 1000 mL

Applying unitary method:

In 100 mL water, the amount of solute (nitrogen gas) dissolved is 0.056 grams

So, in 1000 mL of water, the amount of solute (nitrogen gas) dissolved will be = $\frac{0.056}{100}\times 1000=0.56g$

Converting this solubility into mol/L by dividing with the molar mass of nitrogen gas:

Molar mass of nitrogen gas = 28 g/mol

So, Solubility of nitrogen gas = $\frac{0.56g/L}{28g/mol}=0.2mol/L$

To calculate the Henry's constant we use the equation given by Henry's law, which is:

$C_{N_2}=K_H\times p_{N_2}$ .........(1)

where,

$K_H$ = Henry's constant

$C_{N_2}$ = molar solubility of nitrogen gas = 0.02 mol/L

$p_{N_2}$ = partial pressure of nitrogen gas = 2.38 atm

Putting values in equation 1, we get:

$0.02mol/L=K_H\times 2.38atm\\\\K_H=\frac{0.02mol/L}{2.38atm}=8.40\times 10^{-3}mol/L.atm$

When pressure is changed to 5.00 atm

Now,

$p_{N_2}=5.00atm\\\\K_H=8.40\times 10^{-3}mol/L.atm$

Putting values in equation 1, we get:

$C_{N_2}=8.40\times 10^{-3}mol/L.atm\times 5.00atm=0.042mol/L$

Hence, the molar solubility of nitrogen gas when pressure is increased is 0.042 mol/L

4 0

3 years ago

What is the ph of a buffer prepared by adding 1.00 l of 1.0 m hcℓ to 750 ml of 1.5 m nahcoo? ka = 1.7 x 10-4?

alexandr1967 [171]

Ph = 2.837 ( solution is attached )

5 0

3 years ago

Choose the substance with the lowest surface tension. choose the substance with the lowest surface tension. (ch3)2so ch3ch2ch2ch

8090 [49]

Surface tension is defined as the tendency of elasticity of a liquid surface that makes it to achieve the possible least surface area. It depends upon the intermolecular forces present on the boundary of the surface of the compound and its contact.

n-butane $(CH_{3}CH_{2}CH_{2}CH_{3})$ is non-polar compound and it consist of only weak dispersion forces that are responsible for any contact with the surface.

In comparison to other given substances, n-butane has the weakest dispersion forces. Thus, n-butane has lowest surface tension.

4 0

3 years ago

What factors govern the position of an IR absorption peak? Select one or more correct answers.

Phoenix [80]

Answer:

The factors that govern the position of an IR absorption peak includes:

A.)strength of the bond

C.)masses of the atoms involved in the bond

D.)the type of vibration being observed

Explanation:

Infra red spectroscopy covers a range of techniques, mostly based on absorption spectroscopy.

4 0

4 years ago

n the formation of chloromethane and hydrogen chloride. The overall reaction is 2CH4(g)+3Cl2(g)⟶2CH3Cl(g)+2HCl(g)+2Cl−(g) 2CH4(g

IrinaVladis [17]

Answer:

The total pressure in the flask is 0,619 atm.

Explanation:

For the reaction:

2CH₄(g) + 3Cl₂(g) ⟶ 2 CH₃Cl(g) + 2HCl(g) + 2Cl⁻(g)

The moles of CH₄ in 295 mL at STP are:

n = PV/RT

Where P is pressure (1 atm), V is volume (0,295L), R is gas constant (0,082atmL/molK) and T is temperature (273,15 K)

Replacing, moles of CH₄ are 0,0132 moles

In the same way, moles of chlorine are 0,0324 moles

As 3 moles of Cl₂ react with 2 moles of CH₄, for a total reaction of 0,0132 moles of CH₄ you need:

0,0132 moles CH₄ × $\frac{3 moles Cl_{2}}{2 moles CH_{4}}$ = 0,0198 moles Cl₂. That means that 0,0324-0,0198 = 0,0126 moles of Cl₂ are in excess.

As the reaction reaches in 77%, the moles of CH₄ that don't react are:

0,0132×(100%-77%)= 3,036x10⁻³ moles of CH₄

Also, the moles of Cl₂ that don't react are:

0,0126 + 0,0198×(100%-77%)= 0,0172 moles of Cl₂

The moles produced of each compound are:

0,0132×77% × $\frac{2 moles CH_{3}Cl}{2 moles CH_{4}}$ = 0,0102 moles of CH₃Cl -that are the same moles of HCl and Cl⁻-

Thus, total moles in the flask are:

3,036x10⁻³ moles of CH₄ + 0,0172 moles of Cl₂ + 0,0102 moles of CH₃Cl + 0,0102 moles of HCl + 0,0102 moles of Cl⁻ = 0,0507 total moles

As the volume of the flask is 2,00L and the final temperature is 298 K. The total pressure in the flask is:

P = nRT/V

P = 0,619 atm

I hope it helps!

3 0

4 years ago