D2.3 - Water Potential

Question 1

Front

Answer 1

Back

Question 2

What is hydrogen bonding in water?

Answer 2

Hydrogen bonding occurs when the partially positive hydrogen of one water molecule is attracted to the partially negative oxygen of another.

Question 3

What is the heat of vaporization of water?

Answer 3

The heat of vaporization of water is $2257 ext{ kJ/kg}$.

Question 4

What is the specific heat capacity of water?

Answer 4

The specific heat capacity of water is $4.18 ext{ J/(g·°C)}$.

Question 5

What is the significance of hydrogen bonding in water’s boiling point?

Answer 5

Hydrogen bonding significantly raises water’s boiling point compared to methane, despite water’s lower molecular mass.

Question 6

How is oxygen transported in blood?

Answer 6

Oxygen is slightly hydrophobic and is transported bound to hemoglobin in red blood cells.

Question 7

What factors can be investigated to study cooling with water?

Answer 7

Factors include humidity levels, air movement, and surface area affecting evaporation and cooling.

Question 8

What is the polarity of water molecules?

Answer 8

Water molecules are polar due to the uneven distribution of electrical charge, with oxygen being slightly negative and hydrogen slightly positive.

Question 9

How does sweating help regulate body temperature?

Answer 9

Sweating cools the body by evaporating water, which removes heat due to water’s high heat of vaporization.

Question 10

What is the role of water in biochemical reactions?

Answer 10

Water is crucial for biochemical reactions as many occur in aqueous solutions.

Question 11

What property of water explains surface tension?

Answer 11

Cohesion, caused by hydrogen bonds, allows water molecules to stick together, creating surface tension.

Question 12

What role does water play in blood transport?

Answer 12

Water’s solvent properties allow it to transport hydrophilic substances like glucose and ionic substances like sodium chloride in blood.

Question 13

How do water and methane compare in boiling points?

Answer 13

Water has a boiling point of $100°C$, while methane has a boiling point of $-161.5°C$.

Question 14

What is adhesion in the context of water?

Answer 14

Adhesion is the ability of water to stick to other substances, enabling capillary action.

Question 15

What is the effect of hydrogen bonds on water’s thermal properties?

Answer 15

Hydrogen bonds require energy to break and reform, contributing to water’s high specific heat capacity.

Question 16

What are hydrophilic and hydrophobic substances?

Answer 16

Hydrophilic substances dissolve easily in water, while hydrophobic substances do not.

Question 17

Why is water called the ‘universal solvent’?

Answer 17

Water is called the ‘universal solvent’ because it can dissolve a wide range of substances, crucial for biological processes.