Test 1: Review Sheet for September 30, 2022 Please note: this is a good summary of all topics on our next test. **Anything we have covered in class and in the lab can show up on our test. Good luck!! Chapter 3: -Distinguish between extensive and intensive properties -Distinguish between physical and chemical properties (and physical and chemical changes) -Know the differences betweens solids, liquids, gasses and plasmas -Know the properties of pure substances: elements and compounds -Know the properties of mixtures and be able to distinguish between mixtures and pure substances, and homogeneous and heterogeneous mixtures -Be able to describe all of the physical separation methods: distillation, filtration, chromatography and the properties used to separate mixtures using these techniques. -Be able to classify substances into elements, compounds, homogeneous and heterogeneous mixtures -Be able to explain what happened in the chemical/physical change labs and separation labs. -Be able to explain what happened during the orange soda lab Chapter 2: -Be able to express numbers in proper scientific notation -Be able to multiply, divide, add and subtract numbers in scientific notation -Be able to distinguish between accuracy and precision -Be able to use significant figures properly when taking measurements. -Know the rules for counting significant figures -Know how to perform calculations with the right number of significant figures in the final answer. -Know how to solve density problems and understand the density demonstration with hot and cold water and Coke and Diet Coke -Know the commonly used units for density. -Know how to use factor label method -Know how to perform metric conversions. -Know the fundamental units (a.k.a. SI units), what is meant by a fundamental unit and what the purpose of fundamental units are. -Know how to calculate percent error Chapter 4: Contrast Democritus and Aristotle’s ideas Understand the Law of Conservation Matter, Law of Constant Composition (also known as Law of Definite Proportions) and Law of Multiple Proportions Understand the postulates of Dalton’s Atomic Theory and which are no longer true Be able to explain J.J. Thomson’s experiment, his results and his conclusions Be able to explain Milikan’s oil drop experiment, his results and his conclusions. Be able to explain J.J. Thomson’s Plum Pudding Model Review Questions: The volume of a small piece of gold (density = 19.3 g/cm3) is 24.8 cm3. What is the volume of a piece of silver that has the same mass as gold? (density of silver = 10.5 g/cm3 Write the answer to the appropriate number of significant figures. Answers should also be written in scientific notation. (2.00x 106 – 1 x 104)/2 = (2.00 x 104 x 3.0 x 103) + 5.0 x 108 [2.0 + 0.0000030+ 13.00]/[5.00]= Identify how many significant figures are in each of the following measurements: 187.032 g 0.060100 m3 1.30 x 10-12 kg The volume of rock A is greater than rock B, while the mass of rock B is greater than that of rock A. Which rock has the greater density and why? Convert: 2.00 g/mL to kg/cL. Convert 50 micrograms to decigrams. Classify as element, compound, homogeneous mixture or heterogeneous mixture Hydrogen Vinegar A saturated fatty acid Granite Food coloring Copper we made in the lab You are given a 50 mL beaker of cereal that has been grinded up into a fine powder. Vitamins and minerals (e.g. iron) are then added to it. How would you separate the iron? Is the property physical or chemical? Extensive or intensive? Give the SI unit for area Label the following properties of caffeine as physical or chemical and extensive or intensive: Melting Point, 238oC: It has the ability to dissolves in water: Odorless A student tries to separate black permanent ink into its component dyes using paper chromatography, by allowing water to soak up a strip of paper, past the black marker ink line. Unfortunately, the black marker ink line simply remains where it is! Briefly hypothesize why this might occur, i.e. what property of the black permanent ink is responsible for this observed behavior? Wine contains alcohol. How can you account for the apparent violation of state & federal law when serving pasta with wine sauce to underage persons? Identify the following as chemical/physical changes Bleach turns hair yellow Cutting a bar of sodium metal into pieces with a knife Bananas when exposed to air turn brown Neutralization of a stomach acid with an antacid Melting butter Protein denaturation Baking a cake Opening coke and carbon dioxide is released 14) How should length indicated by the arrow along the ruler be recorded? 0.30 cm +/- 0.1 0.30 cm +/- 0.01 0.35 cm +/- .01 0.35 cm +/- 0.1 0.350 cm +/- .001 15) You are driving along the highway at the speed limit of 60 mph. A police officer measures your speed to be 66 mph, using a damaged radar gun. What is the radar gun’s percent error? 16). A mine in Pennsylvania produces 200 kg of the compound, consisting of 140 kg of iron and 60 kg of oxygen. A small sample of the compound is obtained from Brazil, which consists of 70 kg of iron and 30 kg of oxygen. Which law associated with Dalton’s Atomic Theory that supports this data 17) A graduated cylinder is filled to the level shown by the arrow labeled “E,” in the diagram to the right. After standing for several days, enough water evaporates for the water level to drop to the arrow labeled “D.” How much water has evaporated? 1.2 mL (2) 1.15 mL (3) 8.65 mL (4) 8.7 mL 18. Which aspect of Thomson’s model is still true? Which aspect of his model is false? Chemistry review questions for test 1 ANSWER KEY: 19.3 g X 1 cm3 = 24.8 cm3. X = 479 g 10.5g 479 g 1 cm3 = x X = 45.6 cm3 a) 2.00 x 106 – 0.01 x 106 = 1.99 x 106 1.99 x 106/2 = 1 x 106 6.0 x107 .60 x 108 + 5.0 x 108 = 5.6 x 108 15.0/5.00 = 3.00 A) 6. B) 5 C) 3 Rock B has the greater density because its mass to volume ratio is greater. 2.00 g 1 kg 1000 mL 1L 1 mL x 1000g x 1L x 100 cL = .0200 kg/cL 50 micrograms x 1 gram 10 dg = 5 x 10-4 dg 1 x 106 micrograms x 1 gram Element, homogeneous mixture, compound, heterogeneous mixture,homogeneous and element Using a magnet. Physical and Intensive (iron attracts a magnet no matter how much you have). Size of iron particles (compared to the rest of cereal) is also good. Physical and intensive. meters squared All physical and intensive. This type of black ink is not soluble in water or highly attracted to the paper. When you cook the pasta, the wine boils off first (low boiling point), leaving the flavoring behind- like distillation! C, P, C, C, P, C, C and P C (|66-60|/60) x 100 = 10% Law of Definite proportions. 2 Most of the atom is empty space and the presence of electrons. There is not a sphere of positive charge but a nucleus.