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Karo-lina-s [1.5K]
3 years ago
9

Which of the following is a chemical change?

Chemistry
2 answers:
BigorU [14]3 years ago
8 0

Answer:

burning a piece of paper hope this helps you

nataly862011 [7]3 years ago
3 0

Answer:

Burning a Piece of Paper

Explanation:

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Given that delta hvap is 58.2 kj/mol and the boiling point is 83.4 c 1atm if one mole of this substance is vaporized at 1atm cal
astraxan [27]
Change in Gibb's free energy of system (ΔG) = ΔH - TΔS.........(Eq. 1)
Now, if magnitude of ΔG <0, then reaction is spontaneous.
         if magnitude of ΔG > 0, then reaction is non-spontaneous. 
         At equilibrium, ΔG = 0
When at boiling point, liquid state is in equilibrium with vapour state. Hence, it present case ΔG = 0

∴ Eq 1 becomes, ΔH = TΔS
here, ΔH = 58.2 kj/mol (Given),
∴ At T = 83.4 oC = 356.4 K, ΔS = 0.1633 kj/mol.K
3 0
3 years ago
A sample of gas has a mass of 38.8 mg. Its volume is 224 mL at a temperature of 55 °C and a pressure of 886 torr. Find the molar
Pie

Answer:

4g/mol

Explanation:

Firstly, we can get the number of moles of the gas present using the ideal gas equation.

PV = nRT

Here:

P = 886 torr

V = 224ml = 224/1000 = 0.224L

T = 55 degrees celcius= 55+ 273.15 = 328.15K

R = molar gas constant = 62.36 L⋅Torr⋅K−1⋅mol−1

n = PV/RT

n = (886 * 0.224)/(62.36 * 328.15)

n = 0.009698469964 mole

Now to get the molar mass, this is mathematically equal to the mass divided by the number of moles. We have the mass and the number of moles, remaining only the molar mass.

First, we convert the mass to g and that is 38.8/1000 = 0.0388

The molar mass is thus 0.0388/0.009698469964 = 4g/mol

3 0
4 years ago
We identify nucleic acid strand orientation on the basis of important chemical functional groups. These are the _________ group
zloy xaker [14]

Answer:

We identify nucleic acid strand orientation on the basis of important chemical functional groups. These are the <u>phosphate</u> group attached to the 5' carbon atom of the sugar portion of a nucleotide and the <u>hydroxyl</u> group attached to the <u>3'</u> carbon atom

Explanation:

Nucleic acids are polymers formed by a phosphate group, a sugar (ribose in RNA and deoxyribose in DNA) and a nitrogenous base. In the chain, the phosphate groups are linked to the 5'-carbon and 3'-carbon of the ribose (or deoxyribose) and the nitrogenous base is linked to the 2-carbon. Based on this structure, the nucleic acid chain orientation is identified as the 5'-end (the free phosphate group linked to 5'-carbon of the sugar) and the 3'-end (the free hydroxyl group in the sugar in 3' position).

3 0
3 years ago
How are minute and seconds are related to degrees
jekas [21]

These minutes are further divided into sixty parts called seconds. The words minute and second used in this context have no immediate connection to how those words are usually used as amounts of time. In a full circle there are 360 degrees. Each degree is split up into 60 parts, each part being 1/60 of a degree.

No then contact me about that

5 0
3 years ago
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Environmental scientists are unconcerned with methods to preserve natural resources.
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Answer
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