Chapter 3: Water and Life Flashcards
What is the definition of a Solvent?
A solvent is the dissolving agent of a solution.
What is the definition of a Solute?
A solute is the substance that is dissolved.
What is the definition of a solution?
Together, the solute and solvent form a solution. A solution is a (liquid) homogenous mixture of two substances.
What does it mean, when we refer to a substance as “Hydrophobic?”
“Hydrophobic” refers to substances that lack affinity to water, or are ‘water fearing.’
What does it mean when we refer to a substance as “Hydrophilic?”
“Hydrophilic” refers to substances that possess affinity to water, and are ‘water loving’
What is an Acid? What is a Base? How do they differ?
An acid is a substance that gives up protons(H+ ions) to solutions, therefore increasing their H+ concentration. Acids differ from bases as bases removes/lowers the H+ concentration of solutions. Their functions are contrasted.
What is a buffer solution? Explain its purpose and effectiveness.
A buffer solution acts as both an acid/base, depending on the acidity of the substance it is added to. They balance/ minimize changes to the pH of substances.
What is pH?
The pH of a substance refers to the H+ concentration. The pH scale ranges from 0 (extremely acidic) to 14 (extremely basic), with 7 being the neutral.
NB! pH is indirectly proportional to H+ concentration.
Explain the function of the Bicarbonate Buffer System.
The bicarbonate buffer system is extremely useful in regulating the pH of the blood.
Eqn: H2CO3 —> HCO3 - + H+
If the blood is too acidic, the equilibrium shifts to the left, removing H+ ions, and increasing basicity. If the blood is too basic, the reaction favours the right, releasing H+ ions into the blood, increasing acidity.
What are the emergent properties of water? What do they result from?
High Heat Capacity, High Heat of Vaporization, Cohesion, Adhesion, Good Solvent Properties. They result from water’s ability to Hydrogen Bond.
What is Hydrogen Bonding?
Hydrogen Bonding occurs when H bonds with an electronegative element like oxygen or nitrogen.
Why does Ice float in Water? Explain the science behind this. Why is this important?
As water is in its liquid state, the molecules are constantly moving and transiently(briefly) breaking and reforming hydrogen bonds. However, in its solid state (ice), water molecules are stationary and stuck in a lattice-like structure. This lattice lessens water molecules proximity to each other, making the solid less dense than its liquid state. This is why water floats on ice. It is important as it allows marine life to thrive in colder climates.
Explain High Heat Capacity
A substance’s heat capacity refers to the amount of heat it takes to raise/lower 1g of its temperature by 1 degree (celcius)
Explain Heat of Vaporization
Heat of vaporization refers to the amount of heat needed for 1g of a liquid to evaporate/enter the gaseous state.
What is Cohesion?
