Energy and Temp
What is the scientific law that says energy cannot be created or destroyed, only changed from one form to another?
The Law of Conservation of Energy.
In a chemical formula, what do we call the big number written in front of the whole compound?
A coefficient.
What are the names for the phase changes when a liquid turns into a gas, and when a solid turns into a liquid?
Boiling (vaporization) and Melting (fusion).
What are two units scientists use to measure energy?
Joules (or Kilojoules) and Calories.
What is the huge number 6.02×1023 called?
Avogadro's Number (or one mole).
Why does the temperature stay completely flat on a graph during a phase change?
Because the substance is in phase equilibrium, meaning two states of matter exist at the same time while potential energy changes.
If you heat up a liquid, what happens to the speed and the kinetic energy of its particles?
The particles move faster and their kinetic energy increases.
One mole of any gas will always take up how many liters of space at standard conditions?
22.4 liters.
What do we call the pressure created when a liquid evaporates into a gas?
Vapor pressure.
What is the exact scientific definition of temperature?
A measurement of the average kinetic energy of the particles in a substance.
What is the definition of Molar Mass (also called Gram Formula Mass)?
The total mass in grams of exactly one mole of a substance.
Boiling only happens when a liquid's vapor pressure becomes completely equal to what?
The atmospheric pressure (air pressure pushing down on it).
What is the difference between potential energy and kinetic energy?
Potential energy is stored energy (like bonds or water behind a dam), while kinetic energy is the energy of actual motion.
How do you calculate the Percent Composition by mass of an element in a compound?
Divide the mass of that one element by the total mass of the whole compound, then multiply by 100.
Name the three formulas for heat (q), and explain when you would use the formula q=mcΔT.
The formulas are q=mcΔT, q=mHf, and q=mHv. You use q=mcΔT when a substance is actively changing temperature