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scoundrel [369]
3 years ago
6

Is (H) a positive or negative value

Chemistry
1 answer:
sammy [17]3 years ago
3 0

Answer:

A chemical reaction that has a positive ΔH is said to be endothermic , while a chemical reaction that has a negative ΔH is said to be exothermic . What does it mean if the ΔH of a process is positive? It means that the system in which the chemical reaction is occurring is gaining energy.

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Which of the following is the correct ranking of the three bonds and interactions in order from highest to lowest in terms of th
Nesterboy [21]

Answer:

I > III > II

Explanation:

I) A disulfide bond between two cystines is created when a sulfur atom from one cystine forms a strong, single covalent bond with a sulfur atom from a second cystine. When a disulfide bond is created, each cystine loses one hydrogen atom. The atom count is 11 for a cystine in mid-chain, but changes to 10 if the cystine joins with another in a disulfide bond. This lead to a much more stable intermolecular interaction.

III) Hydrogen Bonding in water

These hydrogen bonds are at best an interaction, inducing slight positive and negative charges in the Hydrogen and Oxygen/Nitrogen atoms.

The Hydrophilic amino acids have O & N atoms, which form hydrogen bonds with water. These atoms have an uneven distribution of electrons, creating a polar molecule that can interact and form hydrogen bonds with water.

The hydrogen bonds aren't as strong as the covalent bonds in disulfides.

II) Hydrophobic interactions between two leucines

A hydrophobic interaction is formed between two nonpolar molecules.

It describes the preference of nonpolar molecular surfaces to interact with other nonpolar molecular surfaces, thereby displacing water molecules from the interacting surfaces.

6 0
4 years ago
What product(s) forms at the cathode in the electrolysis of an aqueous solution of k2so4?
fenix001 [56]
Catod(-)
K⁺
2H20 +2e⁻ ---> H2 +2OH⁻

We can also say, that
K⁺ +OH⁻ +H2  = KOH +H2   
At the cathode KOH and H2 are formed.
8 0
3 years ago
If you decreased the volume of a sample of gas by a factor of three while maintaining a constant pressure, how would the absolut
Rus_ich [418]
<h2>Answers to the whole assignment:</h2>

**Check for proof photos at the bottom.**

**Answers are in bold.**

__________________________________________________________

If you decreased the volume of a sample of gas by a factor of three while maintaining a constant pressure, how would the absolute temperature of the gas be affected?  

✔ it would decrease threefold

A gas at 300 K and 4.0 atm is moved to a new location with a temperature of 250 K. The volume changes from 5.5 L to 2.0 L. What is the pressure of the gas at the new location?  

✔ 9.2 atm

What is the partial pressure of 0.50 mol Ne gas combined with 1.20 mol Kr gas at a final pressure of 730 torr?  

✔ 215 torr

__________________________________________________________

How will the volume of a gas be affected if the pressure is tripled, but the temperature remains the same?  

✔ it is decreased to one third of its original volume

Why might a rubber raft burst if it is left in the sun on a summer day?  

✔ temperature increases, causing interior pressure to increase

__________________________________________________________

Complete the table by filling in the missing information.  

✔ pressure, volume    A  

✔ temperature, moles of gas   B  

✔ Charles’s law    C  

✔ V = kT    D  

✔ temperature, pressure   E  

✔ P = kT    F  

✔ number of moles only    G

__________________________________________________________

Match one graph shown at right to each of the gas laws named below.  

Charles’s law  

✔ d

Gay-Lussac’s law  

✔ b

Boyle’s law  

✔ e

__________________________________________________________

Left answers:  

1.31 atm A

0.44  atm B

Right answers:  

✔ decreases it    

✔ decreases it  

0.12  atm C

__________________________________________________________

<h2>Explanation:</h2>

When decreasing a volume while maintaining the same pressure, the temperature will have to decrease. When volume decreases, particles get squished, increasing pressure. But when temperature decreases, particles move slower, decreasing pressure. The lowered temperature decreases pressure, but the decreased volume increases pressure, so pressure is able to stay constant.

About the 3 main gas laws covered in Edge:

  • Charles's law says that under a constant pressure, when temperature increases, the volume increases, and vice versa. The equation for this law is V₁/T₁=V₂/T₂.
  • Gay-Lussac’s law says that under a constant volume, when temperature increases, the pressure increases, and vice versa. The equation for this law is P₁/T₁=P₂/T₂.
  • Boyle’s law says that under a constant temperature, when volume decreases, pressure increases, and vice versa. The equation for this law is P₁V₁=P₂V₂.

Note that P=pressure, V=volume, and T=temperature. When given a problem, plug in the given values into the correct spots and solve for the unknown value.

Here are photos of Edge. I hope this made your day a little easier.

5 0
3 years ago
Determine whether the following reaction is a Lewis acid/base reaction and if so, what is the Lewis acid: Fe3+(aq) + 6 CN−(aq) →
Aleonysh [2.5K]

Answer: It is a Lewis acid/base reaction, and Fe^{3+} is the Lewis acid.

Explanation:

According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.

Fe^{3+} can readily accept electrons and thus act as a lewis acid which is short of electrons.

CN^- can readily lose electrons and thus act as a lewis base which has excess of electrons.

It is a Lewis acid/base reaction, and Fe^{3+} is the Lewis acid.

4 0
4 years ago
Percent of water in Na2CO3 • 10H2O
Troyanec [42]
Hey there! 

In order to solve for the percentage of water in the compound, you will first need to find its total molar mass. You can do this by adding up the molar masses of each individual element in the compound. Then, you will divide the mass that you find of the water molecules by the total mass to get the percentage. 

→ Na₂CO₃ ×<span> 10 H</span>₂<span>O

</span>→ Na₂ = 22.9898 × 2 = 45.9796
→ C = 12.0107
→ O₃ = 15.999 × 3 = 47.997
→ 10 H₂O = 18.015 × 10 = 180.15

Now, just add all of those numbers up for the total molar mass. 

→ 45.9796 + 12.0107 + 47.997 + 180.15 = <span>286.1373
</span>
The last step is to divide the molar mass of the 10 water molecules by the total mass. 

→ 180.15 ÷ 286.1373 = <span>0.62959 </span>≈ 0.63

Your answer will be about 63%. 

Hope this helped you out! :-)
5 0
3 years ago
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