π Unit 4: Reactions, Energy, & Gases
1. What type of reaction releases heat to the surroundings?
β Exothermic reaction
What does a catalyst do in a chemical reaction?
β It speeds up the reaction by lowering the activation energy.
What is a half-life?
β The time it takes for half of a radioactive substance to decay.
What law describes the inverse relationship between pressure and volume of a gas?
β Boyleβs Law
What does the symbol ΞH represent?
β It represents the change in enthalpy (heat content) of a system.
Whatβs the difference between nuclear fusion and nuclear fission?
β Fusion combines atoms; fission splits atoms.
What is the formula for the ideal gas law?
β PV = nRT
How does increasing temperature affect the rate of a chemical reaction?
β It increases the rate by making particles move faster and collide more often.
What is an alkene?
β A hydrocarbon with at least one double bond between carbon atoms.
In a chemical reaction, what is the energy needed to start the reaction called?
β Activation energy
What is the term for the slowest step in a reaction mechanism?
β The rate-determining step.
What type of particle is released in alpha decay?
β A helium nucleus (2 protons and 2 neutrons).
What happens to the pressure of a gas when temperature increases (if volume stays the same)?
β The pressure increases
If a reaction has a negative ΞG, what does that mean?
β The reaction is spontaneous.
What is the general formula for alkanes?
β CβHββββ