Name: Date: Section:
Post Test: Properties of Matter, Mixtures and Solutions, Chemical Reactions
Test summary: 50 Questions - multiple choice, true/false, matching, reading/interpreting
1 Question (5 pts.) – Writing Inquiry Prompt
Review Directions: To prepare for the Post Test, you should understand the big ideas from the Properties of Matter unit listed on this handout. The information can be found in your handouts, labs, class notes, textbook, and videos as appropriate. In addition to this general review sheet, please study your individual review sheets as well as quizzes and tests for Units #1-2!
Properties of Matter
Define matter and list its properties. Identify the properties that are characteristic properties.
Matter is anything that has both mass and volume. In class, we discovered six specific properties of matter. These properties are organized into two different groups. The first group contains general properties. They include mass and volume (see notes for definitions). Both of these are considered general properties because they cannot be used to accurately identify an unknown substance. The second group contains characteristic properties. They include density, rate of expansion/contraction, amount of heat required to change phase, and reaction to heat. All for properties are characteristic because they are unique to each substance, and they can be used to accurately identify unknown substances.
Define and identify the standards used to measure the mass, volume, and density of different types of matter. What units are used to label these three properties?
A triple beam balance and an electronic scale are both used to measure mass in grams (g). A metric ruler is used to measure the volumes of regular solid objects in cubic centimeters (cm3). A graduated cylinder, along with water displacement, is used to measure the volumes of both irregular solid objects and liquids in milliliters (mL). Once the mass and the volume of an object are measured, the density of the object can be calculated. To calculate density, you divide mass by volume. This gives you an answer in either g/ cm3 or g/mL.
Explain the relationship between mass and weight.
Mass measures the amount of matter inside of an object, while weight measures the pull of gravity on an object. Thus, weight depends on gravity and mass does not. If gravity changes, weight will change. This is why an astrounaut’s weight changes when he or she travels to the moon. However, because mass does not depend on gravity, the astrounaut’s mass would not change during their journey to the moon.
Be able to utilize the formula D=M/V to solve for density, mass, and/or volume.
Make sure you can draw and that you understand the density triangle. This triangle allows you to quickly determine the three formulas below:
D = M / V V = M / D M = D x V
Be able to construct a density column.
We constructed a density column during the liquid section of the density lab. Basically, we poured three different liquids into a single graduated cylinder. Once the liquids were allowed to settle, they formed three separate layers. The liquids behaved this way because their densities were all different from one another. The top liquid was the least dense, and the bottom liquid was the most dense. The liquid in the middle had a density between the other two liquids.
Compare and contrast physical vs. chemical properties.
Physical properties are those that can be easily observed without changing the identify of a substance. A few examples of physical properties include mass, volume, and density (see notes for more examples). When you measure these properties, you do not change the identify of your substance. On the other hand, chemical properties are those that can only be observed when a substance undergoes a chemical reaction and changes its identity. A few examples include flammability, odor change, and thermal decomposition (see notes for more examples). You can only observe these properties when a substance undergoes a chemical reaction and an identiy change.
Compare and contrast the phases of matter.
Solids have particles that are tightly packed together, moving slowly, and low in energy. They also possess definite shape and volume. Liquids have particles that are packed less tightly, moving a little faster, and a little higher in energy. Although they do have definite volume, they do not have definite shape. Gases have particles that are srpead far from another, moving very quickly, and have a lot of energy. They also d not possess definite shape or volume.
Explain the relationship between temperature, density, and phase of matter.
When a substance gains heat, a number of events occur. The temperature increases, the substance expands, the volume increases, and the density decreases. So, as a substance expands and its particles spread apart, it becomes less dense. This explains why gases have such small densities. On the other hand, when a substance loses heat, a number of different events occur. The temperature decreases, the substance contracts, the volume decreases, and the density increases. So, as a substance contracts and its particles pull together, it becomes more dense. This explains why solids have higher densities.
Be able to create and interpret a phase change diagram.
A phase change diagram outlines the temperatures and the times at which a substance undergoes phase changes. This type of diagram has two major setions. The three sloped lines represent specific phases of matter. From left to right, we first contact the solid state, then the liquid state, and finally the gas state. Aside from the sloped lines, we also have two flat lines. These lines represent phase changes. From left to right, we first contact melting (solid to liquid) and then boiling (liquid to gas). If we go from right to left, we first contact condensing (gas to liquid) and then freezing (liquid to solid). You can use this type of diagram to easily determine the time and the temperature at which a substance experiences specific phase changes.
Mixtures and Solutions
Compare and contrast elements and compounds.
Any substance that contains only one kind of an atom is known as an element. Elements cannot be broken down into simpler substances. On the other hand, compounds are formed when two or more elements combine. For this reason, compounds can be broken down into simpler substances.
Explain the relationship between solutions, solutes, solvents, and solubility.
In general, solubility is the ability of a substance to dissolve. In the process of dissolving, the substance which is being dissolved is called a solute, while the substance in which the solute is dissolved is called a solvent. A mixture of solute and solvent is called a solution. For example, when we insert sugar into water it will dissolve. In this process, sugar is the solute because it dissolves, and water is the solvent because the sugar dissolves in it.
Describe how chromatography can be used to separate solutes.
Chromatography can be used to separate, and therefore identify, the solutes dissolved in a solvent. With an appropriate solvent, often water, the solutes can “un-dissolve” from their solution and separate onto a surface according to weight. Lighter solutes will separate further down on a chromatograph than heavier ones. In the end, how each material separates is characteristic to that material, so it can be used to identify the parts of a solution.
Chemical Reactions
Physically describe and locate the three parts of the atom. Identify their electrical charges.
Refer to Lesson 2 for the notes on protons (+), electrons (-), and neutrons (no charge).
Be able to use the periodic table to find information about elements (atomic number, atomic mass, atomic symbol, classification of elements by periods and groups.)
Compare and contrast families/groups and periods.
See notes written on student Periodic Table for both above.
Be able to construct an electron shell diagram.
See class notes and homework on electron shells.
Be able to name a binomial compound.
See class activity sheet “Compounds: What’s in a name?”
Compare and contrast covalent versus ionic bonding.
See class notes “Bonding.”
What are the reactants and products in a chemical reaction?
Reactants are two or more chemicals that chemically combine to produce something different, a product.
Hydrogen and Oxygen react (reactants) to produce Water (product)
Explain the role of energy in chemical reactions.
Energy goes into or comes out of chemical reactions in the form of heat.
Explain the Law of Conservation of Mass.
In a chemical reaction running in a closed system, the mass of the reactants will equal the mass of the products, even if a gas is produced. The atoms are simply re-arranged from one form in the reactants to a different form in the products. In a phase change in a closed system, there is no loss/gain of mass either as the matter is simply changing from solid to liquid to gas or any combination of phases.