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Which of the statements regarding alcohols and ethers are true? 1-Propanol is more likely to be a liquid at 50 °C50 °C than is m

irina [24]

Answer:

Following statements are true:

1-Propanol is more likely to be a liquid at 50 than is methoxyethane (ethyl methyl ether).

Alcohol molecules can form hydrogen bonds among themselves;ether molecules cannot

Explanation:

1-Propanol is more likely to be a liquid at 50 than is methoxyethane (ethyl methyl ether).

This is true

Propanol has a boiling temperature (this is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor) of 97-98 °C while methoxyethane a boiling point of 7.4 °C.

This means at 50 °C propanol is liquid but methoxyethane at 50°C is a gas.

Methoxyethane (ethyl methyl ether) is more soluble in water than is 1-propanol.

This false:

Propanol has a hydrogen bonding. The OH on the alcohol can form a hydrogen bond (as a hydrogen acceptor and donor). Water can hydrogen bond. This means alcohol is will disolve in water. ( Remember Like dissolves like). So, when you have a molecule that can act as a donor and acceptor you end up with a much better interaction with water and end up with something that is more miscible. Ethers are only acceptors since they do not have a hydrogen attached to the oxygen. So, they can only accept a proton from water.

Methoxyethane (ethyl methyl ether) is more likely to be a liquid at 50 °C50 °C than is 1-propanol

This is false because propanol has a boiling temperature (this is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor) of 97-98 °C while methoxyethane a boiling point of 7.4 °C.

This means at 50 °C propanol is liquid but methoxyethane at 50°C is a gas.

Alcohol molecules can form hydrogen bonds among themselves;ether molecules cannot

This is true because:

Ether molecules cannot form hydrogen bonding between themselves because the oxygen atom is attached to 2 alkyl or aryl groups R-O-R, e.g diethyl ether, or Ar-O-Ar, such as diphenylether (C6H5)2O

C2H5-O-C2H5,m or dimethyl ether CH3—O-CH3. however they can between ether molecules and other molecules containing hydrogen atoms, such as alcohols, CH3OH. Any molecule with the hydrogen attached to a strongly electronegative element e.g Nitrogen or fluorine.

Methoxyethane (ethyl methyl ether) has a higher boiling point than 1-propanol.

This is false: Methoxyethane has a boiling point of 7.4 °C while propanol has a boiling point of 97-98 °C. This can be shown because at roomtemperature Methoxyethane is a gas but propanol is a liquid.

6 0

2 years ago

When a 18.0 mL sample of a 0.308 M aqueous hydrofluoric acid solution is titrated with a 0.361 M aqueous sodium hydroxide soluti

sleet_krkn [62]

Answer:

pH = 12.8

Explanation:

HF + NaOH → F⁻ + Na⁺ + H₂O

1 mole of HF reacts with 1 mole of NaOH

Initial moles of HF and NaOH are:

HF = 0.018L × (0.308mol / L) = 5.544x10⁻³mol HF

NaOH = 0.023L × (0.361mol / L) = 8.303x10⁻³mol NaOH

That means moles of NaOH remains after reaction are:

8.303x10⁻³mol - 5.544x10⁻³mol = 2.759x10⁻³moles NaOH

Total volume is 18.0mL + 23.0mL = 41.0mL = 0.0410L

Molar concentration of NaOH is

2.759x10⁻³moles NaOH / 0.0410L = 0.0673M = [OH⁻]

pOH = - log [OH⁻] = 1.17

As pH = 14 - pOH

pH = 12.8

4 0

2 years ago

THIS IS URGENT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Pani-rosa [81]

Answer:

1- 1.54 mol.

2- 271.9 kPa.

3- Yes, the tires will burst.

4- 235.67 kPa.

5- As, the temperature increased, the no. of molecules that has minimum kinetic energy increases as shown in image 1 that represents the Maxwell’s Distribution of Speeds of molecules. "Kindly, see the explanation and the attached images".

Explanation:

Q1- How many moles of nitrogen gas are in each tire?

To calculate the no. of moles of nitrogen gas in each tire, we can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the nitrogen gas (P = 247.0 kPa/101.325 = 2.44 atm),

V is the volume of the nitrogen gas (V = 15.2 L),

n is the no. of moles of the nitrogen gas (n = ??? mole),

R is the general gas constant (R = 0.082 L.atm/mol.K),

T is the temperature of the nitrogen gas (T = 21°C + 273 = 294 K).

∴ n = PV/RT = (2.44 atm)(15.2 L)/(0.082 L/atm/mol.K)(294.0 K) = 1.54 mol.

Q2: What would the maximum tire pressure be at 50 degrees C?

Now, the temperature is raised to be 50°C (T = 50°C + 273 = 323 K).

The pressure can be calculated using the general gas law: PV = nRT.

∴ P = nRT/V = (1.54 atm)(0.082 L/atm/mol.K)(323.0 K)/(15.2 L) = 2.68 atm = 271.9 kPa.

Q3: Will the tires burst in Moses Lake? Explain.

Yes, the tires will burst because the internal pressure be 271.9 kPa that exceeds 270 kPa, the pressure above which the tires will burst.

Q4: If you must let nitrogen gas out of the tire before you go, to what pressure must you reduce the tires before you start your trip? (Assume no significant change in tire volume.)

To get the pressure that we must begin with:

Firstly, we should calculate the no. of moles at:

T = 55°C + 273 = 328 K,

Pressure = 270 kPa (the pressure above which the tires will burst). (P =270 kPa/101.325 = 2.66 atm).

V = 15.2 L, as there is no significant change in tire volume.

∴ n = PV/RT = (2.66 atm)(15.2 L)/(0.082 L.atm/mol.K)(328 K) = 1.5 mol.

1.5562 moles of N₂ in the tires will give a pressure of 270 kPa at 55°C, so this is the minimum moles of N₂ that will make the tires burst.

Now, we can enter this number of moles into the original starting conditions to tell us what pressure the tires will be at if we start with this number of moles of N₂.

P = ???

V = 15.6 L.

n = 1.5 mol

T = 21°C + 273 = 294.0 K

R = 0.0821 L.atm/mol.K.

∴ P = nRT/V = (1.5 mol x 0.082 x 294.0 K) / (15.6 L) = 2.2325 atm = 235.67 kPa.

So, the starting pressure needs to be 235.67 kPa or just under in order for the tires not to burst.

Q5: Create a drawing of the tire and show a molecular view of the air molecules in the tire at 247 kpa vs the molecular view of the air molecules after the tires have been heated. Be mindful of the number of molecules that you use in your drawing in the before and after scenarios. Use a caption to describe the average kinetic energy of the molecules in both scenarios.

As, the temperature increased, the no. of molecules that has minimum kinetic energy increases as shown in “image 1” that represents the Maxwell’s Distribution of Speeds of molecules.

The no. of molecules that possess a critical K.E. of molecules increases due to increasing the temperature activate the motion of molecules with high velocity as

(K.E. = 3RT/2), K.E. directly proportional to the temperature of the molecules (see image 2).

Also, the average speed of molecules increases as the K.E of the molecules increases (see image 3).

3 0

2 years ago

A pH of 2 indicates a(n) _____.

solniwko [45]

A pH of 2 indicates a acid

6 0

3 years ago

You use 4.98 g of Na2SO4, how many grams of barium sulfate are produced? Na2+Ba(NO3)2= ?

Kaylis [27]

Answer:

Mass of barium sulfate = 8.17 g

Explanation:

Given data:

Mass of sodium sulfate = 4.98 g

Mass of barium sulfate produced = ?

Solution:

Na₂SO₄ + Ba(NO₃)₂ → BaSO₄ + 2NaNO₃

Moles of sodium sulfate:

Number of moles = mass/molar mass

Number of moles =4.98 g / 142.04 g/mol

Number of moles = 0.035 mol

Now we will compare the moles pf sodium sulfate and with barium sulfate.

Na₂SO₄ : BaSO₄

1 : 1

0.035 : 0.035

Mass of barium sulfate:

Mass = number of moles × molar mass

Mass = 0.035 mol ×233.4 g/mol

Mass = 8.17 g

6 0

2 years ago