Answer:
D. Sweat evaporates from your skin
Explanation:
A physical change is a reversible process, no new substance is formed. A physical change does not affect the chemical composition of a substance.
Sweat evaporation from the skin is a physical change, because the change that occur is merely a change of state, Liquid to Gaseous state, no new substance is formed.
You can't really describe it but this is what it looks like http://www.chemspider.com/Chemical-Structure.453291.html
Question:
At standard temperature and pressure, the volume of a tire is 3.5L. What is the new pressure if the temperature outside is 296k and its weight causes the volume of the gas is 2.0 L?
Answer:
The new pressure is: 1.896 atm
Explanation:
At standard temperature and pressure, we have:
Outside, we have:
Required
Determine the new pressure
Using combined gas law, we have:
This gives:
Solve for 
The balanced chemical equation of the reaction described above is,
C2H6O + O2 --> H2O + C2H4O2
If we have 3.84 g of oxygen, we divide by its molar mass.
n = (3.54 g Oxygen gas) x (1 mole O2/ 32 g O2)
n = 0.11 moles O2
Using ratio and proportion,
number of moles of ethanol = (0.11 moles O2) x (1 mole C2H6)
= 0.11 moles C2H6
Then, we multiply the calculated value to its molar mass, 46 grams /mol.
mass of ethanol = (0.11 mol) x (46 grams / mol)
= <em>5.06 grams</em>
B- Carbon nitrogen and oxygen. All organisms are made up of carbon, oxygen is essential to breath, and nitrogen makes up most of earth's atmosphere.
