All forms of crystalline carbon have the same structure. True or False

Suppose you have three monodisperse polymer samples, A, B, and C, with molar masses of 100,000 g/mol, 200,000 g/mol, and 300,000

EastWind [94]

Answer:

a) Number-average molar mass: 163,700g/mol

Weight-average molar mass: 200,000g/mol

b) Number-average molar mass: 200,000g/mol

Weight-average molar mass: 233,300g/mol

Explanation:

The number-average molar mass is based on mole% and weight-average molar mass is based on weight%, thus:

a) In equal proportions by weight:

number-average molar mass:

1g A× $\frac{1mol}{100,000g}$ = 1x10⁻⁵ moles A

1g B× $\frac{1mol}{200,000g}$ = 5x10⁻⁶ moles B

1g C× $\frac{1mol}{300,000g}$ = 3,33x10⁻⁶ moles C

Total moles are:

1x10⁻⁵ A + 5x10⁻⁶ B + 3,33x10⁻⁶ C = 1,833x10⁻⁵ moles.

Percent A: $\frac{1x10^{-5}}{1,833x10^{-5}}$ ×100 = 54,5%

Percent B: $\frac{5x10^{-6}}{1,833x10^{-5}}$ ×100 = 27,3%

Percent C: $\frac{3,33x10^{-6}}{1,833x10^{-5}}$ ×100 = 18,2%

number-average molar mass:

0,545*100,000g/mol + 0,273*200,000g/mol + 0,182*300,000g/mol = 163,700g/mol

weight-average molar mass:

0,333*100,000g/mol + 0,333*200,000g/mol + 0,333*300,000g/mol = 200,000g/mol

b) In molar ratio 1:1:1

weight-average molar mass:

1mol A× $\frac{100,000g}{1mol}$ = 100,000g A

1mol B× $\frac{200,000g}{1mol}$ = 200,000g B

1mol C× $\frac{300,000g}{1mol}$ = 300,000g C

Total mass is:

100,000 A + 200,000 B + 300,000 C = 600,000 g.

Percent A: $\frac{100,000}{600,000}$ ×100 = 16,7%

Percent B: $\frac{200,000}{600,000}$ ×100 = 33,3%

Percent C: $\frac{300,000}{600,000}$ ×100 = 50,0%

Weight-average molar mass:

0,167*100,000g/mol + 0,333*200,000g/mol + 0,500*300,000g/mol = 233,300g/mol

number-average molar mass:

0,333*100,000g/mol + 0,333*200,000g/mol + 0,333*300,000g/mol = 200,000g/mol

I hope it helps!

4 0

4 years ago

What is the electron configuration for Ga

Alex Ar [27]

The electron configuration is Ar 3d10 4s2 4p1.

3 0

3 years ago

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Why is it important to analyze data?

gayaneshka [121]

Answer:

It is important to analyze data to further understand what's going on. By analyzing data, you know more about what you are investigating. Without analyzing data, you may find it harder to figure something.

7 0

3 years ago

Match each description below with the name of the local wind system being described. warm, dry downslope wind affecting Southern

nadya68 [22]

Answer:

warm, dry downslope wind affecting Southern California - Santa Ana wind

a seasonally changing wind- monsoon

wind blowing from a valley up a mountain slope - valley breeze

generated by cold thunderstorm downdrafts - haboob

Explanation:

The Santa Ana wind occurs in early autumn. They bring hot and dry weather to areas around the South-West coast. They move at high speeds, affecting most parts of Southern California.

Monsoon is a seasonal wind that blows across Southern Asia. It usually blows in summer. It is a a seasonally changing wind.

Valley breeze is an example of convection current in nature. It is produced by rapid warming of the valley floor leading to the expansion of air making it to flow up the slopes. At night, radiation from the surface cools the slopes. This leads to the rise of cooler and denser air which drains into the valley.

Haboob is generated by cold thunderstorm downdrafts. It is associated with large sandstorms and dust storms.

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3 years ago

Nuclear energy is currently used in which three kinds of vehicles?

qaws [65]

Nuclear power plants produce little to no greenhouse gas.

Nuclear power plants produce a large amount of energy for a small mass of fuel.

8 0

3 years ago

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