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2 years ago

50 pts don't dare to answer wrong or just write irrelevant.

Chemistry

1 answer:

sweet [91]2 years ago

4 0

Answer/Explanation:

Part 1 and 3: Test tube 4. The hot water and Acid added to the substance makes it much more reactive, which is the reason why the new substance is bubbling. Hot water allows the particles in a chemical reaction have enough force and more chances to go through actual reaction process. This also caused it to create the most bubbles.

Part 2 and 4: Test tube 1 had the least amount of chemical reactivity. Cold water slows down the amount of times a particle in the substance hits another. This reduces the chance of it reacting and the strength of it's reaction. Test tube 1 was also missing the citric acid. Since acids have low pH it is very reactive with other particles with substances that contain less than 8 valence electrons. Without the acid it doesn't have ad much urge to react with. The lower the pH the better reactivity.

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Which energy stored between plates of capacitor?

Mrac [35]

Answer: Electric energy

Explanation: Electrical energy is stored between plates in electric field

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3 years ago

The cyclohexane ring is essentially free of ring strain because Check all that apply.

NikAS [45]

Answer:The following statements are correct: 1,2 and 6

Explanation:

1.The cyclohexane ring adopts a chair conformation in order to minimize its torsional strain. In chair conformation 4 carbon atoms are in one plane 1 carbon atom is above that plane and the other 1 carbon atom is below that plane .This leads to chair conformation in which the bond angles are very close to the ideal tetrahedral angle of 109.5 degrees. The C-C-C bond angle in chair conformation is 110 degrees which is almost equal to the ideal tetrahedral angle.

2. In cyclohexane molecule as the molecule adopts a chair conformation in order to eliminate the torsional strain which would occur if the cyclohexane ring were to be planar. Torsional strain is basically the inter electronic repulsion between the atoms that do not share a bond. So this strain happens on account of eclipsing atoms. In case of eclipse structure there would be a lot of torsional strain. In case of chair conformation all the C-H bonds happen to be completely staggered in nature to eliminate the torsional strain.

3. The ring strain in case of cycloalkanes are dependent upon the number of CH₂ groups present as that would determine the size of the ring and subsequently its structure ,whether the ring would be 5 , 6 or 7 membered .Cyclohexane is a 6 -membered as there are 6CH₂ groups in it and the existence of chair conformation is only for Cyclohexane or for molecules having 6-membered ring . Any change in number of CH₂groups would lead to a different conformational structure.

4.All the bond angles in cyclohexane ring is approximately 110 degrees which is almost equal to the ideal terahedral bond angle. So the bond angles in cyclohexane are optimal.

5.The C-H bonds in cyclohexane are always staggered and never eclipsed in order to reduce there torsional strain.

6.All the bonds in cyclohexane ring are staggered to eliminate the torsional strain. It is quite evident that the cyclohexane ring is completely stable free of the ring strain.So there are no eclipsing bonds present in cyclohexane.

So the statements which are correct 1,2 and 6

4 0

3 years ago

What is the mass in grams, if you have 8.42 x 10^18 atoms of Bromine

Dahasolnce [82]

Answer:

84.2 grams

Explanation:

you have to multiply 8.42x10^18 to get the answer above

8 0

3 years ago

The following table lists molecular weight data for a polypropylene material. Molecular Weight Range (g/mol) xi wi

nikklg [1K]

Answer:

a) the number-average molecular weight is 32,400 g/mol

b) the weight-average molecular weight is 36,320 g/mol

c) the degree of polymerization is 770

Explanation:

Given the data in the question;

Molecular Mean Number Weight Number Weight

weight average average

(g/mol) Mi(g/mol) xi wi xiMi wiMi

8,000-16,000 12,000 0.07 0.03 840 360

16,000-24,000 20,000 0.15 0.09 3000 1800

24,000-32,000 28,000 0.26 0.21 7280 5880

32,000-40,000 36,000 0.27 0.27 9720 9720

40,000-48,000 44,000 0.18 0.28 7920 12320

48,000-56,000 52,000 0.07 0.12 3640 6240

∑ Mn=32,400 Mw=36,320

so;

a) the number-average molecular weight

Mn = ∑Mixi

so from the table above; summation of Row Mixi

Mn = ∑Mixi = 32,400

Therefore, the number-average molecular weight is 32,400 g/mol

b) the weight-average molecular weight

Mw = ∑Miwi

so from the table above; summation of Row Miwi

Mw = ∑Miwi = 36,320

Therefore, the weight-average molecular weight is 36,320 g/mol

c) the degree of polymerization

the degree of polymerization of polypropylene can be determined using number-average molecular and repeat unit molecular weight.

now, for polypropylene { CH₂ = CH - CH₃ }

the repeat unit consist of 3 carbon atoms and 6 hydrogen atoms

given that;

Atomic weight of Carbon mC = 12.01 g/mol and

Atomic weight of Hydrogen mH = 1.008 g/mol

now we find the repeat unit molecular weight of polypropylene

m = nCmC + nHmH

where n is the number of repeat of atoms

so we substitute

m = ( 3 × 12.01) + ( 6 × 1.008)

m = 36.03 + 6.048

m = 42.078 g/mol

now we calculate the degree of polymerization;

DP = Mn / m

so we substitute

DP = 32,400 / 42.078

DP = 769.9985 ≈ 770

Therefore, the degree of polymerization is 770

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2 years ago

Use the mole concept to calculate the number of atoms that are in a 1.75-mol sample of CHCl3.

Fiesta28 [93]

This is how I got to that answer. Since we don't know how many atoms there are in a mole, we use the number 6.02 x 10^-23. Now, just plug in what you have in the equation:

<span>1.75 moles ChCl3 x (6.02 x 10 ^-23) / 1 mole = 1.0535 x 10^-22 atoms. </span>

6 0

3 years ago