States of Matter
What are the three common states of matter?
Solid, liquid, and gas.
According to Boyle’s Law, what happens to pressure when volume decreases?
Pressure increases.
What is the difference between a homogeneous and heterogeneous mixture?
Homogeneous mixtures are evenly mixed; heterogeneous mixtures are unevenly mixed.
What is the law of conservation of energy?
Energy cannot be created or destroyed, only transferred or transformed.
What pH value is considered neutral?
7.
What is diffusion?
The movement of particles from an area of high concentration to low concentration.
Which gas law states that volume increases as temperature increases?
Charles’ Law.
What does “soluble” mean?
Able to dissolve in a solvent.
Is melting ice endothermic or exothermic?
Endothermic.
What ion do acids produce in water?
Hydrogen ions (H⁺).
Which intermolecular force is the strongest: dispersion, dipole-dipole, or hydrogen bonding?
Hydrogen bonding.
What temperature unit must always be used in gas law calculations?
Kelvin
What is the formula for molarity?
Molarity = moles of solute ÷ liters of solution.
What happens to particles when temperature increases?
Their kinetic energy increases and they move faster.
What happens in a neutralization reaction?
An acid and a base react to form water and a salt.
Why do gases spread out to fill a container?
Gas particles move freely and constantly in random motion.
A gas has a volume of 2.0 L at 300 K. If the temperature increases to 600 K, what is the new volume?
4.0 L.
If 2 moles of NaCl are dissolved in 1 liter of water, what is the molarity?
2 M.
What is specific heat?
The amount of energy needed to raise 1 gram of a substance by 1°C.
What is the pH of a strong acid?
Less than 7, usually close to 0–3.
Explain why water has surface tension.
Water molecules are attracted to each other through hydrogen bonding, creating strong cohesion at the surface.
A gas occupies 22.4 L. How many moles of gas are present at STP?
1 mole.
A solution contains 15 g of solute and 85 g of solvent. What is the percent by mass?
15%.
Why does water temperature stay constant during boiling even when heat is added?
The energy is used to break intermolecular forces instead of increasing temperature.
If the hydrogen ion concentration increases, what happens to pH?
The pH decreases.