Bell Work 1 / Atomic Models Place the following men in order that they contributed to the modern atomic model and then match the term that goes with each. 1. JJ Thomson a. atom is indivisible 2. John Dalton b. Cathode Ray Tube 3. Democritus c. Solar System Model 4. Neils Bohr d. Plum Pudding Model 5. Earnest Rutherford e. First Atomic Model

Bell Work 2 / Sig Fig’s How many Sig fig’s are in the following? 1.0 X 10^2 f. 11.030 0.00004302 g. 4.80 312.15 h. 0.23100 Perform the following operations, and express each result to the correct Sig Fig: 0.102 x 0.0821 x 273 3. 0.14 x 6.022 x 273= 1.01 2. 98.36 – 4.258 + 16.98 = 4. 1.230 x 10^5 0.29 x 10^4

Bell Work 3 / Sig Fig’s 2 Perform the following operations, and express each result to the correct Sig Fig: 0.102 x 0.0821 x 273 3. 0.14 x 6.022 x 273= 1.01 2. 98.36 – 4.258 + 16.98 = 4. 1.230 x 10^5 0.29 x 10^4

Bell Work 3 / Phy and Chem Changes Label each property as either physical or chemical   ____________1. chemical formula H2O ____________2. forms a green carbonate when exposed to moist air ____________3. Remains unchanged when in the presence of nitrogen ____________4. Colorless ____________5. Solid at normal temperatures and pressure ____________6. Ability to combine with another substance ____________7. Melting point ____________8. Liquid at normal temperature and pressure ____________9. Boiling point is 100.0o C ____________10. Conducts electricity ____________11. Density is 1g / cm3

Bell Work 4 / Quantitative and Qualitative Classify the following as: Quantitative or qualitative observations.   My eyes are blue. The reaction produced a bad smell. Your average in chemistry is 92.2% Physics is a difficult subject.

Bell Work 5 / Calibration curve 1. In your own words describe what a calibration curve is and how they are used?

Bell Work 6 / Empirical Formulas 1. A compound contains the elements copper and chlorine in a ratio of 1 mole of copper : 2 moles of chlorine. a. What is the empirical formula?   b. What is the percent composition of copper? (show all work) c. What is the percent composition of chlorine? (show all work) d. If the molar mass is 269.2g what is the molecular formula of the compound? e. How many grams of copper would be in a 15.89 g sample of CuCl2 ?

Bell Work 6 / Empirical Formulas 1. A compound contains the elements copper and chlorine in a ratio of 1 mole of copper : 2 moles of chlorine. a. What is the empirical formula?   CuCl2 (my subscript is not working) b. What is the percent composition of copper? (show all work)   Cu = 63.6 63.6 / 134.6 = %47.25   Cl = 2 x 35.5=71.0 Total Mass = 134.6 g c. What is the percent composition of chlorine? (show all work)   71.0 / 134.6 = %52.75   d. If the molar mass is 269.2g what is the molecular formula of the compound?   269.2 / 134.6 = 2 Cu2Cl4 e. How many grams of copper would be in a 15.89 g sample of CuCl2 ? 15.89 x .4725 = 7.51 grams

Bell Work 7 / Formula for a Hydrate A 15.67 g sample of a hydrate of magnesium carbonate was heated, without decomposing the carbonate, to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate?

Bell Work 8 / Stoichiometry 1. In the chemical reaction sodium chloride is mixed with silver nitrate, If you started with 2.678 g of sodium chloride how much precipitant can be formed?

Bell Work 9 / Combustion With a Twist 1 1. A compound contains only carbon, hydrogen and oxygen. Combustion of 10.68 mg of the compound yields 16.01 mg of CO2 and 4.37 mg of H2O. The molar mass of the compound is 176.1 g / mol. What are the empirical and molecular formulas of the compound?

Bell Work 10 / Limiting Reactant Sodium hydroxide (NaOH) reacts with phosphoric acid (H3PO4) to form sodium phosphate (Na3PO4) and water (H2O) by the reaction: 3 NaOH(aq) + H3PO4(aq) → Na3PO4(aq) + 3 H2O(l) If 35.60 grams of NaOH is reacted with 30.80 grams of H3PO4, a. How many grams of Na3PO4 are formed? b. What is the limiting reactant? c. How many grams of the excess reactant remains when the reaction is complete?

Bell Work 11 / Limiting Reactant Take the reaction: NH3 + O2    NO + H2O. In an experiment, 3.25 g of NH3 are allowed to react with 3.50 g of O2.  a. Which reactant is the limiting reagent? b. How many grams of NO are formed? c. How much of the excess reactant remains after the reaction?

Bell Work 12 / Dilutions Dilutions – you need to make 800.0 mL of a 0.25 M solution of HCl. The only available HCl is concentrated (12 M). How would you do this? Being able to prepare dilutions is a very common application of chemistry. Our department buys concentrated acids, but normally uses more dilute solutions of these acids in our labs. Therefore, it is important to know how to correctly dilute.

Bell Work 13 / Spectroscopy List the four types of spectroscopy from your notes. 2. What type of spectroscopy would be the best tool to analyze the concentration of the carotene macromolecule, which gives the orange color to carrots, in carrot juice? Why?   A. UV-Vis spectroscopy B. IR spectroscopy C. Mass spectroscopy D. Photoelectron spectroscopy 3. What type of spectroscopy would be the best tool to analyze a clear and colorless solution for the presence of a functional group like an alcohol group (-OH)? Why? A. UV spectroscopy B. IR spectroscopy C. Mass spectroscopy D. Photoelectron spectroscopy

Bell Work 13 / Electron Configuration 7. Which of the following is the correct electron configuration for the bromide ion, Br-? a) [Ar] 4s24p5 b) [Ar] 4s23d104p5 c) [Ar] 4s23d104p6 d) [Ar] 4s23d104p65s1 e) [Ar] 4s23d103p6 What element is represented by the following Electron Configuration 1. 1s2 2s2 2p6 3s2 3p6        2. 1s2 2s2 2p6 3s2 3p6 4s2 3d3        3. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1

Bell Work 13 / Electron Configuration 7. Which of the following is the correct electron configuration for the bromide ion, Br-? a) [Ar] 4s24p5 b) [Ar] 4s23d104p5 c) [Ar] 4s23d104p6 d) [Ar] 4s23d104p65s1 e) [Ar] 4s23d103p6 What element is represented by the following Electron Configuration 1. 1s2 2s2 2p6 3s2 3p6        2. 1s2 2s2 2p6 3s2 3p6 4s2 3d3        3. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1 Bromine has a total of 35 electrons. [Ar] accounts for 18 electron. Answer b) contains 17 electrons. Together they total 35 electrons. Bromine is also on the 4th energy level and is the 5th element over in the p-block. Argon Vanadium Gallium