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ryzh [129]
2 years ago
12

When does the composition of a substance does not change?

Chemistry
1 answer:
blagie [28]2 years ago
4 0
I think when it does not react with anything I think
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Calculate the molar mass for HCN.<br> 0.2703 g/mol<br> 2.703 g/mol<br> 27.03 g/mol<br> 270.3 g/mol
elixir [45]

Answer:

27.03 g/mol

Explanation:

Molar Mass of HCN

Mass of Hydrogen : 1.008

Mass of Carbon: 12.01

Mass of Nitrogen: 14.01

Molar Mass of HCN =

1.008 + 12.01 + 14.01=

27.03 g/mol

7 0
3 years ago
Illustrate the x- and y-axes to show the reaction pathway and potential energy, in kilojoules. Ensure your energy intervals are
Rufina [12.5K]

Answer:

Enthalpy of a reaction = P - R  

Synthesis: ΔH = 25 kJ - (-30 kJ) = 55 kJ  

Single Replacement: ΔH = 30kJ - 65 kJ = -35 kJ  

Double Replacement: ΔH = 60 kJ - 10 kJ = 50 kJ

Explanation:

6 0
3 years ago
Draw the two chair conformations of cis 1 chloro 2 methylcyclohexane
Mrrafil [7]
In chair conformations of cyclohexane, Cl group is on the first C and methyl group is on the second C. In the cis conformation both groups should be in the same orientation, either both side chains should be up and up or down and down. In this figure its up and up. 
2 figures are drawn as when the chair conformation flips, the axial groups become equatorial and equatorial groups become axial. But they remain as up or down .
When A flips to B, Cl goes from axial to equatorial and CH3 goes from equatorial to axial but both remain up.

6 0
3 years ago
4. Why is radiocarbon measurement useless when trying to measure things that died
julsineya [31]

Answer:

Radiocarbon measurement or radiocarbon dating is a method that is used to measure the age of the carbon-based material in living organisms.

Radiocarbon dating is able to estimate age of fossils that are younger than 50,000 years and unable to measure things that died longer than 200,000 years ago because fossils that are too old do not contain carbon or carbon get vanished from too old fossils of organisms. Some of the fossils also get contaminated due to environmental conditions and during teh collection or preservation process.

Thus,  radiocarbon measurement is useless when trying to measure most rocks older than 50,000 years.

4 0
2 years ago
The Density of this log is 1.75g/cm3. If we cut this log in half, what is the density of the log? Make sure to show your work an
swat32

Answer:

The density remains the same

Explanation:

The density remains the same because cutting the object in half will divide the mass & volume by the same amount. The density cant be changed no matter what happens to it.

5 0
3 years ago
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