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3 years ago

Why isn't energy required for the passenger molecule to be carried across the cell membrane by the carrier molecules?

1 answer:

4 0

Energy is not required for the passenger molecule to be carried across the cell membrane by the carrier molecule simply because they are moving down a concentration gradient, that is to say movement is from an area of high concentration to an area of low concentration.

When particle move from areas of high concentration to areas of low concentration, they do not need energy. For example this is how the aroma of cooking spreads from the kitchen (higher concentration) to all the other rooms in the house.

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Which of the following is a disadvantage of electronic communication?

ziro4ka [17]

Answer:

DISADVANTAGES OF ELECTRONIC COMMUNICATION

The cost of development: Electronic communication requires huge investment for infrastructural development. Frequent change in technology also demands further investment. Legal status: Data or information, if faxed, may be distorted and will cause zero value in the eye of law.

5 0

3 years ago

Question 4 How many carbon-carbon triple bonds are present in a molecule of 4,5-diethyloctane?

ivann1987 [24]

Answer:

We will have zero bonds

Explanation:

In this case, we have to start with the structure of 4,5-diethyloctane. This name ends with the suffix "ane" therefore we have an alkane. All the alkanes are made with single bonds between carbons and single bonds between carbon and hydrogen.

The molecule will have a carbon chain of eight carbons and we will have 2 branches, one ethyl on carbon 4 and another ethyl on carbon 5. (see figure 1)

5 0

3 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

3 years ago

A compound contains 64 g of o and 8 g of h. what is the empirical formula for this compound?

kaheart [24]

The empirical formula is obtained by calculating the mole ratios of the atoms in the elements.
The number of moles =mass/ R.A.M
For hydrogen, no. of moles=8/1=8
For oxygen, no. Of moles=64/16=4
The tabular solution is attached.

6 0

3 years ago

Read 2 more answers

Various pieces of safety equipment are used in the lab to provide protection against injury. Which of the following pieces of la

alina1380 [7]

The lab safety equipment that is least likely to be used if proper eye protection is used is d. fire extinguisher. A fire extinguisher serves to put fires out by cutting off the oxygen to a fire and operates by a spraying action. Even if an injury occurs, a fire extinguisher is extremely unlikely to be used.

6 0

4 years ago

Read 2 more answers