chem II lab midterm 💔💔

Molality (m)

the number of moles of solute divided by the total mass of the solvent in kilograms (mol/kg). It is highly useful in thermodynamics because mass does not change with temperature

Molarity (M)

the number of moles of solute per liter of solution (mol/L). Because liquid volume expands and contracts with temperature, molarity can change even if no solute is added

Mole fraction (X)

a unitless ratio representing the moles of one specific component divided by the total moles of all components combined in the solution

Mole percent (mol%)

simply the mole fraction of a component multiplied by 100% to express it as a percentage

Mass percent (wt%)

the mass of the solute divided by the total mass of the solution (solute + solvent), multiplied by 100%

Zero Order

[reactant] vs. Time, negative (-k)

The Idea: The speed of the reaction never changes, no matter how much stuff is left. The reactant simply disappears at a constant, steady rate.

First Order

ln[reactant] vs. Time, negative (-k)

The Idea: The reaction slows down as reactant is used up. It creates a gentle curve, not a straight line.

Second Order

1/[reactant] vs. Time, positive (+k)

The Idea: The reaction slows down even faster because it requires molecules to collide with each other. The curve is very steep.

Third Order

1/[reactant]² vs. Time, positive (2k)

The Idea: This requires three molecules to hit each other at once, making it incredibly rare and highly sensitive to concentration changes.