Chapter 15
What's the neutral pH number
7
What’s the difference between heat and temperature?
Heat is energy that flows due to a temperature difference; temperature is how fast particles are moving (their average kinetic energy).
Q: What 3 things must happen for a reaction to occur (CEO)
collision, energy, orientation
Am I acidic or basic? 3
acidic
Can an exothermic reaction slow down if the temperature increases?
Yes。 If it’s reversible, higher temperatures may favor the backward (endothermic) direction.
what pH has a solution of this: [H₃O⁺] = 1 × 10-8 M
8
Fill in the blank: Δ_ = ΔH – TΔS
G
What does a catalyst do to a reaction?
lowers activation energy and adjust orientation
What is a equivalence point?
The point in a titration where the amount of acid equals the amount of base.
What happens to the rate of most reactions when temperature increases, and why?
Increases, because more particles have enough energy to overcome the activation energy barrier
What is the pH of 1 × 10⁻⁴ M
4
Energy can neither be created nor be destroyed, it can only be transferred from one form to another.
First law of thermodynamics:
True
What happens to the reaction rate when you increase the concentration of a reactant
It goes faster because more particles are bumping into each other.
What color does it turn into for acid when using a litmus indicator
red
What is the self-ionization of water? when 2 water molecules come together to form H3O+ and ___
OH⁻
What is Hess's Law
ΔG = ΔH – TΔS
Define Intermediate in an equation
This appears during a reaction but gets used up and doesn’t show in the final equation.
Why does a reaction slow down as it approaches completion
There are fewer reactant particles left to collide, reducing the collision frequency
Why doesn’t a catalyst change the final amount of product?
It just helps you get there faster. It speeds up both directions equally, so the balance stays the same.
What is the pH of this equation [OH⁻] = 1.0 × 10⁻³ M
11, convert to [H₃O⁺] = 1.0 × 10⁻¹¹,
The entropy of any isolated system always increases.
Second law of thermodynamics
Two reactions have the same ΔH, but one is much slower. Why?
Because rate depends on activation energy, not just energy change. Slow reactions may have high barriers to start.
Can a spontaneous reaction happen slower than a nonspontaneous one?
Yes, because spontaneity (ΔG < 0) doesn’t tell you how fast—it only tells you if it’s thermodynamically favorable
A reaction has a positive ΔG, but it still happens. How?
It gets energy from outside. For example, photosynthesis uses sunlight to power the reaction.