Honors Chem Semester 1 Study Guide (Fall 2024-25) PDF

C. Free Response Practice Problems:​ ​ ​ ​ ​ KEY ​ To receive full credit on problems, show all work including formula used/plug-in numbers, units throughout, answers rounded for correct significant figures, correct final unit & box around it. ​ Partia...

C. Free Response Practice Problems:​ ​ ​ ​ ​ KEY ​ To receive full credit on problems, show all work including formula used/plug-in numbers, units throughout, answers rounded for correct significant figures, correct final unit & box around it. ​ Partial credit will be given, so attempt all questions. ​ It is recommended that as you go through these questions, you write down hints for them that you need to put on your notes sheet ​ The learning targets are provided for each so that you can go back to the FRQ practice on the unit test study guides or to re-watch a specific LT video 1. (LT 1D & CER) Density: Using the following data table, write a paragraph in the form of claim, evidence, reasoning to predict which substance is most likely water, which has a density of 1.00 g/mL. Include units throughout and round final answers for significant figures when app. ​ Density Calculations (i.e. show full work) Substance Mass (g) Volume (mL) Formula: A 3.65 1.54 B 12.15 4.51 C 9.95 10.00 Claim: _____Substance C is most likely water____________ Evidence: ____The density of substances A, B and C are 2.37 g/ml, 2.69 g/ml and 0.995 g/ml respectively Reasoning: ____Water has a density of 1.00 g/ml. Since the density of substance is 0.995 g/ml, this is the closest density and most likely water.__________ (hint: notice the density doesn’t have to be exactly the same as water. Due to lab error this likely wouldn’t happen) 2. (LT 2G/CER) Radioactive Decay: All of the following isotopes are unstable. Predict which type of radioactive decay it will most likely undergo. Show a balanced nuclear equation as evidence & then give reasoning (which should include a discussion of # of neutrons & protons. Use complete sentences in the claim & reasoning. a) potassium-42 Predict (Claim): K-42 will undergo beta decay. Balanced Nuclear Equation (Evidence): Reasoning: The mass number of K-42 is 42, which is higher than the average atomic mass of K which is 39.10 amu. When the mass number is greater than the average atomic mass, there are too many neutrons so a neutron decays into a proton and the beta particle. b) uranium-238 Predict (Claim): U-238 will under alpha decay. Balanced Nuclear Equation (Evidence): Reasoning: The atomic number of U-238 is 238, which is greater than 82. This means it has too many of both neutrons and protons to be stable, so it will release an alpha particle to rapidly decrease in size.. c) magnesium-20 Predict (Claim): Mg-20 will undergo electron capture. Balanced Nuclear Equation (Evidence): Reasoning: The mass number Of Mg-20 is 20, which is lower than the average atomic mass of Mg which is 24.10 amu. When the mass number is less than the average atomic mass, there are too many protons so an electron is captured to make a neutron. 5. (LT 2H) Half Life of Radioisotopes: Show work or justify your answer: A scientist has a 400. g sample of the radioisotope, phosphorus-32. The half-life of phosphorus-32 is 14.3 days. What mass in grams of the original sample will remain after 71.5 days? 6. Use the graph on the right to answer the following: a.​ What is the independent variable (and unit)? Time (minutes) b.​ What is the dependent variable (and unit)? Mass remaining (mg) c.​ What is the half-life of the isotope (with unit)? 1.0 minute d.​ Name 5 rules of good graphing that are observed here. ○​ Descriptive title ○​ Both axes labeled ○​Axes labels have units ○​Graph axes are scaled to take up most of the graph space ○​ Clear data points (though this would be improved with point protectors) 7. a) (LT 3B) Electrons in Atoms: Write the full electron configuration and orbital diagram for palladium (Z = 46) in order of increasing energy. Electron configuration: 1s22s22p63s23p64s23d104p65s24d8 Orbital diagram: ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 1s 2s 2p 3s 3p 4s 3d ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑_ ↑_ 4p 5s 4d b) Write the abbreviated electron configuration for lead (Z = 82) in order of increasing energy. _______[Xe]6s24f145d10 _____________________ 9. (LT 3E, 3F) Mixed Nomenclature: For each of the following, first determine the class of compound and write it in the blank before: ionic (I), molecular (M) or acid (A). Then use the appropriate nomenclature rules to write either the formula or name for the given information. I (ionic) M (molecular) Formula Name A (Acid) I iron(II) sulfide a) FeS *don’t forget the roman numeral!!! I b) Co(HCO3)2 cobalt (II) hydrogen carbonate M Dinitrogen pentoxide c) N2O5 *NOT pentAoxide!!! I d) (NH4)2CrO4 Ammonium chromate A e) HNO3 Nitric acid I f) CsClO3 cesium chlorate I g) Mg3P2 Magnesium phosphide M h) CF4 Carbon tetrafluoride I Ba(OH)2 i) barium hydroxide *note the parentheses!!! M j) NO Nitrogen monoxide M k) SCl6 sulfur hexachloride I l) SnO2 tin (IV) oxide  A m HBr Hydrobromic acid 10. (LT 3E) Ionic Bonding Model: Consider the reaction between sodium and sulfur, answer the following questions. a)​ Represent the reaction between the two using Lewis dot structures, i.e. write the Lewis dot structures for atoms of each before the arrow and then use an arrow to show how electrons would be transferred between these atoms to satisfy the octet rule. Be sure to use the correct ratio of atoms and ions. Write the Lewis dot structure for the resulting ions after the arrow. b) Write the chemical formula for the compound formed. _____Na2S____________ c) Write the chemical name of the compound formed. ______sodium sulfide___________________ 11. (LT 3F, 3G) Molecular Bonding Models: For each of the formulas given, complete the table with the appropriate information. 8. (LT 3F, 3G) Molecular Bonding Models: For each of the formulas given, complete the table with the appropriate information. Formula a) PH3 b) H2O c) CH4 Lewis Structure (box the final structure if work is done) Molecular trigonal pyramidal bent tetrahedral Shape Polar or polar polar nonpolar Nonpolar 12. (LT 3F, 3G) Molecular Bonding Models: For each of the following, determine the total valence electrons, complete the octets on the Lewis Structures by adding missing lone pairs and use that information to complete the table. Formula Total Lewis Structure Molecular Shape Polar or Valence (complete the octets by Nonpolar Electrons placing missing lone pairs) Molecule? a) CS2 C: 1(4e-)=4e- S: 2(6e-)=12e- Linear Non-polar 16e- b) C2H2 C: Linear Non-polar 2(4e-)=8e- S: **No lone pairs needed; all 2(1e-)=2e- atoms are satisfied and 10 total e- are already showing 10e- b) H2CO H: 2(1e-)=2e- C: Trigonal Planar Polar 1(4e-)=4e- O: 1(6e-)=6e- 12e-