Answer:
(C) O, C, H, N
Explanation:
<u>Roughly 96% of mass of human body is made up of four elements which are oxygen, carbon, nitrogen and hydrogen.</u>
Oxygen and hydrogen are predominantly found in the water, which makes up about 60% of body's weight. Carbon is synonymous with the life. The central role of carbon is due to fact that it has four bonding sites which allow for building of long and complex chains of the molecules. Moreover, these carbon bonds can be formed and also be broken with amount of energy which makes life alive. Nitrogen is found in organic molecules, including amino acids which make up the proteins, and nucleic acids which make up the DNA.
Answer:
a) ΔHvap=35.3395 kJ/mol
b) Tb=98.62 °C
Explanation:
Given the reaction:
C₇H₁₆ (l) ⇔ C₇H₁₆ (g)
Kp=P(C₇H₁₆) since the concentration ratio for a pure liquid is equal to 1.
When
T₁=50°C=323.15K ⇒P₁=0.179
T₂=86°C=359.15K ⇒P₂=0.669
The Clasius-Clapeyron equation is:
ΔHvap=35339.5 J/mol=35.3395 KJ/mol
Normal boiling point ⇒ P=1 atm
Hence, we find the normal boiling point where:
T₁=323.15K
P₁=0.179 atm
P₂=1 atm
T₂=371.77 K= 98.62 °C
Answer:
Dehydration synthesis reactions build molecules up and generally require energy, while hydrolysis reactions break molecules down and generally release energy. Carbohydrates, proteins, and nucleic acids are built up and broken down via these types of reactions, although the monomers involved are different in each case.
Explanation:
Increasing the pressure on a reaction involving reacting gases increases the rate of reaction. Changing the pressure on a reaction which involves only solids or liquids has no effect on the rate.
If the units for gases were the same as the units for numbers would be too small to be convenient.
For example, the density of iron is 7.87 g/cm³.
Using the same units, the density of hydrogen is 0.000 0899 g/cm³.
It is much more convenient to express the density in numbers that are easier to visualize: 0.0899 g/L, and that is still a small number.
