Chem 7 Pre-Comp Study Guide (2022-2023) Answers PDF

# Chem / Pre-comp Study Guide (2022-2023) ## Unit 1: Laboratory Safety, measurement, and significant figures 1. List PPE most effective at reducing risk when working with substance with following hazard label: - gloves - hair tie - lab coat ## Lab Tools/Equipement: Match the equipment...

# Chem / Pre-comp Study Guide (2022-2023) ## Unit 1: Laboratory Safety, measurement, and significant figures 1. List PPE most effective at reducing risk when working with substance with following hazard label: - gloves - hair tie - lab coat ## Lab Tools/Equipement: Match the equipment and complete the table. | Equipment/Tool | Letter Match | What is it used for? | |---|---|---| | Graduated cylinder | D | measuring liquids precisely | | Erlenmeyer Flask | B | mixing & heating substances | | Volumetric Flask | E | making solutions precisely | | Beaker | A | mixing & heating substances | 2. For each measurement below, state the number of significant digits. - a. 0.0150 cm: `3` - b. 2500 mL: `2` - c. 3.010 x 10⁵ s: `4` - d. 0.0400 mol/L: `3` ## Taking Measurements: Write the measurement using proper units. 3. - [Image of a graduated cylinder with the measurement at ~63.5 mL] Answer: 63.5 mL # Unit 2: Matter- Types and Properties of matter 4. Classify each of the following properties of matter as physical [P] or chemical [C]. - a. Density: `P` - b. Flammable: `C` - c. Boils at 200°C: `P` - d. Malleable: `P` - e. Good conductor of heat: `P` - f. Dissolving salt in water: `P` - g. Stretching copper into wire: `P` - h. Burning gasoline: `C` - i. Hammering a metal into foil: `P` - j. A blue solid formed from mixing of two aqueous solutions: `C` 5. Classify the following diagrams as element, compound, or mixture. - [Image of a diagram showing a mixture of circles] - `M` - [Image of a diagram showing a mixture of circles] - `E` - [Image of a diagram showing a mixture of circles] - `C` # Unit 3: States of Matter 9. Label the phase change. - Au(l) freezing → Au(s) - NaCl(s) Melting → NaCI(l) - C2H3O2(g) Condensation → C2H3O2(l) - C10H8(s) Sublimation → C10H8(g) 10. Label the heating curve with the phase changes. [Image of a heating curve] - 1. Sublimation - 2. Freezing - 3. Melting - 4. Condensation - 5. Vaporization 11. Complete the table. | | Solid | Liquid | Gas | |---|---|---|---| | Shape | definite | Shape of container | indefinite shape | | Volume | Fixed volume | Measurable volume | Indefinite volume | | Particle diagram | [Image of a solid particle diagram] | [Image of a liquid particle diagram] | [Image of a gas particle diagram] | | Movement of particles | Slow | Slide, move freely | Compressible and move rapidly | # Unit 4: The Periodic table 12. Fill in the table. | Element | Group | Period | Chemical Family | |---|---|---|---| | Sr | 2 | 5 | alkaline earth metal | | Na | 1 | 3 | alkali metal | | He | 18 | 1 | noble gas | | Br | 17 | 4 | halogen | | Ag | 11 | 5 | transition metal | 13. Complete the table below: | | Sodium-21| Carbon-14 | |---|---|---| | Number of protons | 11 | 6 | | Number of neutrons | 10 | 8 | | Number of electrons | 11 | 6 | | Number of valence e- | 1 | 4 | | Atomic number | 11 | 6 | | Mass Number | 21 | 14 | 14. Circle the smaller atomic radius. - a. Al, Mg, P: `Mg` - b. Te, S, Se: `S` - c. Ba, Si, F: `F` 15. Circle the highest ionization energy. - a. Li, Na, K: `Li` - b. Ar, Cl, Si: `Ar` - c. K, Se, Mn: `Mn` 16. Circle the atom or ion that has the largest radius. - a. Na or Na⁺¹: `Na` - b. Al³⁺ or Al: `Al` - c. Cl^- or Cl: `Cl<sup>-</sup>` - d. O^2- or O: `O<sup>2-</sup>` 17. Match each term to its definition. - Anion: *Negatively charged ions* - Mass Number: *Tells us the number of protons & neutrons in the nucleus* - Group: *A column on the periodic table* - Cation: *Atoms that have lost electrons* - Isotopes: *Atoms of the same element with different numbers of neutrons* - Valence Electron: *Electron in the highest energy level for an atom* - Period: *A row on the periodic table* 18. Complete the table. | Element | #Valence electrons | Most likely ion charge | Cation or Anion | |---|---|---|---| | Sr | 2 | 2+ | Cation | | Al | 3 | 3+ | Cation | | S | 6 | 2- | Anion | | Br | 7 | 1- | Anion | | Na | 1 | 1+ | Cation | 19. Provide the element symbol that matches each description below. - The noble gas element in period 5: `Xe` - The metal with the smallest molar mass in group 13: `Al` - A non-metal with 35 protons in its nuclei: `Br` - The only liquid metal at room temperature: `Hg` - An element that forms diatomic molecules, found in period 3: `Cl` - An element that forms diatomic molecules, found in period 2: `N` - The element whose atoms have 3 valence electrons, in period 4: `Ga` - An element that reacts explosively with water, found in period 4: `K` 20. Write the electron configuration. - a. Cl: 1s²2s²2p⁶3s²3p⁵ - b. Na: 1s²2s²2p⁶3s¹ - c. Li: 1s² - d. S: 1s²2s²2p⁶3s²3p⁴ 21. Write the noble-gas notation. - a. S: [Ne]3s²3p⁴ - b. Ca: [Ar]4s² - c. Mg²⁺: [He]2s²2p⁶ - d. Ar: [Ne]3s²3p⁶ # 22. Fill in the table below. Classify the substances as ionic or covalent compound. | Bond Type | Chemical Formula | IUPAC Name | |---|---|---| | ionic | AlBr₃ | Aluminum bromide | | ionic | Fe(NO₃)₃ | Iron (III) nitrate | | ionic | Ca₃N₂ | Calcium nitride | | ionic | AgNO₃ | Silver nitrate | | ionic | (NH₄)₃PO₄ | Ammonium phosphate | | covalent | N₂O₄ | Dinitrogen tetroxide | | ionic | Ga₂S₃ | Gallium sulfide | | ionic | Zn(OH)₂ | Zinc hydroxide | | ionic | K₂SO₃ | Potassium sulfite | | covalent | AsCl₃ | Arsenic trichloride | | ionic | PbCl₂ | Lead(II) chloride | | ionic | Al₂O₃ | Aluminum oxide | | covalent | SF₆ | Sulfur hexafluoride | | covalent | PCl₅ | Phosphorus pentachloride | # Chem 7 Pre-comp Study Guide (2022-2023) 23. Draw the Lewis Structures for the following compounds. | Chemical Formula | Lewis Structure (Don't forget to write the number of valence electrons) | |---|---| | H₂ | H-H: H: 2ve | | F₂ | :F-F: F: 12ve | | O₂ | :O=O: O: 12ve | | N₂ | :N≡N: N: 10ve | | HCl | H-Cl: H: 1ve Cl: 7ve, 8ve | | H₂O | H-O-H: H: 1ve O: 6ve, 8ve | | H₂Se | H-Se-H: H: 1ve Se: 6ve, 8ve | | CH₄ | H C H: C: 4ve, H: 1ve, 8ve | | CCl₄ | :Cl: C: 4ve, Cl: 7ve, 32ve | 24. Draw the Lewis Dot Diagrams for neutral atoms of the following elements: - a. Aluminum: `Al.` - b. Magnesium: `Mg..` - c. Carbon: `.C.` - d. Phosphorus: `:P.`