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Learn about the basics of chemistry, including the Kinetic Theory of Matter, states of matter, phase changes, density, and calculating properties.
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Regular Chemistry KMT and Density notes
What is chemistry? • Chemistry: The science that deals with ______________, structure, properties, and transformations of substances. • Careers that need a knowledge of chemistry
______________ is anything that has mass and takes up space.
Kinetic Theory 1. Kinetic Energy is energy _________________ 2. Kinetic theory states that all tiny particles of matter are in _________________ *It applies to all states of matter* ex) even the particles in your desk are moving
3 Main States of Matter The 3 main states of matter are: SOLIDS, LIQUIDS & GASES
Your goal! • To think of matter as particles. All matter is made of atoms. • You and your team will be assigned a state and you will answer questions on where and how the particles are moving in that state.
States of Matter Practice Which state of matter has particles with the highest kinetic energy? Which state of matter has particles with the lowest kinetic energy? Which state of matter has the lowest density?
Phase Changes • A _________________occurs when matter is transformed from one state to another. • It is important to note that the substance itself is not changed, only the state. We will discuss 7 different phase changes.
Phase Changes _________________occurs when matter changes from a solid to a liquid. _________________occurs when matter changes from a liquid to a solid.
Phase Changes _________________ occur when matter changes from a liquid to a gas. _________________occurs when matter changes from a gas to a liquid.
Phase Changes _________________occurs when matter changes from a solid directly to a gas completely skipping the liquid phase. _________________occurs when matter changes from a gas directly to a solid again skipping the liquid phase.
Phase Diagrams • _________________ : A graph of temperature v.s. pressure and it’s effect on phase • Think about what we know and place where you think solid liquids and gases would be…
_________________ : Any lines between each phase • If you are on this line, both phases can actually be present at the same time!!
Triple point of cyclohexane • The _________________is the temperature and pressure where all three states of a substance can exist!!
The _________________is the point at which the liquid/gas boundary ends, and substances above this temperature and/or pressure are called “supercritical fluids”.
You will need to be able to identify phase changes on a phase diagram. They are labeled on the phase diagram.
Density _________________ : The mass of an object per unit volume Density quantifies how tightly packed molecules are Density of a substance does not change, regardless of size!! Why??
An object will float if less dense then liquid it’s immersed in. • Rank the liquids in order of increasing density
Density Column • You must figure out which liquids are more dense and less dense FIRST, then you can build you column • When you’re building your column, tilt the grad cylinder and GENTLY add the liquid on top with the pipette • Figuring out densities, only use 1 mL! • Final density column should have 2-3 mL of each liquid.
Calculating Density Density = mass / volume D = m V units of density: g/cm3 or g/mL
Mass • Mass: The amount of matter an object has. • Is different than weight!! Weight is the force due to gravity. • Mass does not change, weight can change. • Units for mass, grams: • Gram, g (digital scale gives you grams!) • Kilogram, Kg (SI base unit)
Volume Volume = l x w x h Units = cm3 , L 1 mL = 1 cm3
How to calculate volume? • 1. If a perfect square or rectangle, measure length x width x height • 2. Everything else…water displacement!!
Measuring Volume by Displacement Vsolid = Vfinal - Vinitial
Example Problems 1. Calculate the density of a piece of iron that has a mass of 16.400 g and a volume of 2.08 cm3.
Calculate the density of a metal, if a piece weighing 0.625 kg causes the water level in a graduated cylinder to rise from 10.3 mL to 80.2 mL.
2. What is the mass of a block of wood that has a volume of 5.6 cm3 and a density of 0.75 g/cm3?
3. What is the volume of an object that has a mass of 42.3 g and a density of 3.25 g/cm3?