Honors Chemistry Summer Assignment Page 1 Honors Chemistry Summer Assignment 2014-2015 Materials needed for class: Scientific or Graphing Calculator Mrs. Dorman ldorman@ringgold.org Notebook with folder or 3-ring binder Assignments: (Can be accessed from Ringgold or Mrs. Dorman s website) www.ringgold.org http://mrsdorman-chemistry.wikispaces.com/ A. Due the first day of school for a grade: 1. Complete the given assignments a. Complete Graphing Assignment -1 Excel graph -1 graph created by hand on graph paper -Graph Analysis Questions b. Measurement Assignment c. Current Event Assignment d. Staple in the order listed above 2. Have all sheets of notes, from the summer assignment, printed, hole punched and in your notebook. B. You will be quizzed over ALL material covered in the summer assignment and notes within the first week. Please be aware that some of the material found in these assignments is a review of topics covered in your high school science and math courses. Some of the material presented may be challenging or new; work through ALL questions and use the given notes to help you through the material. In the Science Department, we take Academic Integrity seriously, and will expect the same from you. Academic misconduct is any attempt by a student to gain an academic advantage, or to help others do so, through dishonest actions. All work is expected to be your own. Do NOT complete these assignments with the help of anyone else. Any suspicion of academic misconduct will result in a failing grade on the entire assignment.
Honors Chemistry Summer Assignment Page 2 Graphing Notes Slope: the formula for the straight line going through the points (x1, y1) and (x2, y2) is given by: m = rise = y = y 2 y 1 run x x 2 x 1 y-axis: Dependent Variable (directly affected by the independent variable) x-axis: Independent Variable (controlled by the experimenter) If time or volume is one of your variables, they will almost always be put on the x-axis. Much of the data that you will collect is quantitative, and there are times when data should be displayed in a graph, for easy analysis. You may be asked to use graph paper, or a computer program, such as Microsoft Excel. However you construct your graph, the following rules will always remain true: Example Data for CO2 gas: Temperature ( o C) Pressure (kpa) 25.94 99.9 47.32 102.81 73.26 119.82 108.64 145.04 122.79 138.14 151.09 147.04 184.11 157.78 269.02 187.12 1. Include a descriptive title at the top of the graph. This should clearly tell what your graph is about. It must be concise and to the point. * In this class, the title of your graphs will include both variables being investigated. Example: Relationship between pressure and temperature for CO2 gas 2. Label each axis. Give each axis a title AND include units. * Independent variable on the x-axis. Example: Temperature ( C) * Dependent variable on the y-axis.. Example: Pressure (kpa) 3. Make the origin a point on the graph if it is a realistic data point. That is, unless your data makes this unrealistic. Example: Looking at the graph below, the data does not go through the origin so (0 C,0 kpa) will NOT be a point for the data. 4. Never use loose leaf or blank paper. In order for your graph to be useful, the intervals must be uniform. Free-hand graphs are inaccurate and useless. * Use graph paper or a computer program every time. 5. USE THE ENTIRE GRAPH Select intervals that will show as much detail as possible, while still allowing the graph to fit in the allotted space. * To figure out how to scale your graph, you must first determine the largest and smallest variables (range) on each axis. * Then you must determine how much room you have on each axis. *Then use the following equation:
Honors Chemistry Summer Assignment Page 3 *scale = max value min value * Round answer up to a whole number. # of boxes * Each interval or box must represent the same number of units. 6. Do not JUST connect the dots * Plot your points and THEN draw a best-fit curve or line with a ruler or the graphing program. * The line of best fit is the line that comes the closest to the largest number of data points. * Use a clear ruler to draw the line and move it around until you find a place where approximately half the points are on each side of the line. Example: A BAD best-fit line: Example: A GOOD best-fit line:
Honors Chemistry Summer Assignment Page 4 7. Extend your best-fit line to cross both axes. Important information can be predicted based on the intersecting points. * For the example the line would have to be extended to both the x-axis and y-axis. 8. FOR A HANDDRAWN GRAPH (NOT FOR EXCEL), when you must determine the slope of a line, circle the two points that appear to lie ON THE LINE. Next to these points list the coordinates of these points. 9. FOR A HANDDRAWN GRAPH (NOT FOR EXCEL), using the selected points calculate the slope. Include units in your calculation AND your answer for slope. Example: m = m = Y 2 Y 1 X 2 X 1 157.78kPa - 119.82kPa 184.11 o C - 73.26 o C m = 0.3424kPa / o C 10. DO NOT do steps 8-9 for Excel Graphs. For Excel graphs, you will follow the How to use Excel Notes directions. Include an equation for the line which is calculated using the program. 11. Give the meaning of the slope relationship in a sentence. Pressure is directly proportional temperature. As the pressure increases by 0.3424 kpa, the temperature increases by 1 C. *See below Graphical Methods and Analysis Notes for other relationships.
Honors Chemistry Summer Assignment Page 5 Graphical Methods and Analysis Notes A graph is one of the most effective representations of the relationship between two variables. The independent variable (one controlled by the experimenter) is usually placed on the x-axis. The dependent variable (one that responds to changes in the independent variable) is usually placed on the y-axis. It is important for you to be able interpret a graphical relationship and express it in a written statement and by means of an algebraic expression. When you state the relationship, tell how y depends on x ( e.g., as x increases, y ). *For additional help with graphing, watch the following links: Graphing data by hand- http://www.youtube.com/watch?v=guyrmdces00 Graphing data by spreadsheet- http://www.youtube.com/watch?v=yvyvhu83_6y
Honors Chemistry Summer Assignment Page 6 How to use Excel Notes *Directions are for version 2003. To show a linear relationship using Excel complete the following steps: 1. Open Microsoft Excel. 2. Enter the X values in column A. 3. Enter the Y values in column B. 4. Press the chart button in the toolbar, OR under Insert in the menu header, select Chart. 5. Select plot type "XY scatter". Press <Next>. 6. Set the data range by selecting all the data. (On the actual spreadsheet, click on a corner box that contains the data you are trying to graph. Then, drag the mouse until all boxes with the data you want graphed is selected. Do NOT include the titles.) 7. Click on the Series tab. Make sure the proper X and Y values are selected. (If you put X as column A and Y as column B, this will be done automatically. In any case, make sure the values next to X-axis reflect the location of the X values on the spreadsheet, and the values next to Y-axis reflect the location of the Y values.) For example, on a density plot the mass should be on the Y-axis, and volume on the X-axis. Press <Next>. 8. Fill in the titles and labels. Don't forget to list the units! Press <Next>. 9. Select "As Object in Sheet 1". Press <Finish>. To draw a straight line thru the data: 1. Under Chart in the menu header, select "Add Trendline". 2. Select Linear. Press the Options tab. 3. If the plot is to go thru the origin, check the "Set Intercept" box, and enter 0 in the box. 4. To show the equation of the line (y=mx +b), check the "Show Equation" box or "Display Equation on Chart" box. Press <OK>. 5. To change the scale to make the plot take up most of the space, right click on a gridline and select "format axis". Set both the x and y minimum to 0. Extrapolation (extend trendline): estimating outside the known range 1. To change the range your Trendline covers, right click on the actual best-fit line and select "format trendline". Under the options tab, change the forward and backward forecast units as needed to extend the trendline through the ENTIRE graph. 2. Forecast until the line crosses the x-axis and/or y-axis.
Honors Chemistry Summer Assignment Page 7 How to use Excel Notes *Directions are for version 2007. To show a linear relationship using Excel, complete the following steps: 1. Open Microsoft Excel. 2. Enter the X values in column A. 3. Enter the Y values in column B. 4. Select (highlight) all the data you have entered. 5. Under Insert, click Scatter, and choose the first option (Scatter with only markers). 6. Check that the proper X and Y values are selected the values next to the X-axis should reflect the location of the X values on the spreadsheet, and the values next to the Y-axis should reflect the location of the Y values. If you entered X as column A and Y as column B, this will be done automatically. 7. To delete the legend, select the legend ( Series ) and hit backspace. 8. Under Chart Tools, click the Layout tab and choose Chart Title to add a title. 9. Click Axis Titles to add labels for the X-axis and Y-axis. Don t forget to list the units! To draw a straight best fit line through the data: 1. Under the Layout tab, click Analysis, click Trendline, and choose Linear Trendline. 2. Right-click on the trendline and choose Format Trendline. 3. If the plot is to go through the origin, check box for Set Intercept and enter 0. 4. To extrapolate (extend) the trendline, under Forecast, change the Forward and Backward periods as needed. Extend the trendline through the entire graph! (Forecast until the line crosses the X-axis or Y-axis.) 5. To display the equation of the line (y=mx+b), check the box for Display Equation on chart. 6. To change the scale to make the plot take up most of the space, right-click on the X-axis and choose Format Axis. Set the minimum to 0. Then do the same for the Y-axis.
Honors Chemistry Summer Assignment Page 8 Graphing Assignment 1. Prepare an Excel graph for Data Table 1 (below) and one by hand on graph paper for Data Table 2. 2. Be sure to include all the necessary information required (detailed in the "Graphing Notes" handout). 3. For Microsoft Excel graphs, completing each step in the notes will lead you to great success. Data Table 1 (Excel graph): The following data was collected for a sample of silver. Volume (ml) Mass (g) 0.7 7.35 2.3 24.02 7.5 76.75 8.7 92.85 13.1 139.04 17.0 178.59 30.2 315.82 Data Table 2 (hand drawn graph): The following data was collected for a reaction of baking soda and vinegar. Time (s) Amount of Reactant (g) 9.8 25.99 21.2 20.01 29.7 14.78 43.0 9.28 56.4 4.84 61.9 0.29 Graph Analysis: Neatly written or typed on a separate sheet of paper. 1. Using your Excel Graph for Data Table 1, what is the slope of the line? Explain how you figured out that answer. Do NOT calculate using 2 points. 2. Calculate the slope for the hand drawn graph 2. Show all work. Mark points on graph appropriately (see steps #8 and 9). 3. Explain the relationship shown in graph 1. See step 11 of Graphing Notes and Graphical Method/Analysis Notes. 4. Explain the relationship shown in graph 2. See step 11 of Graphing Notes and Graphical Method/Analysis Notes. 5. Using graph 1, if you have 5.0 g of silver, what is its volume? Briefly show or explain work. 6. Using graph 1, if you have 50.0 ml of silver, what is its mass? Briefly show or explain work. 7. Using graph 2, if 15 s have elapsed, what is the mass of reactant remaining? Briefly show or explain work. 8. Using graph 2, how many grams of reactant were present at the beginning of the reaction? Briefly show or explain work.
Honors Chemistry Summer Assignment Page 9 Measurement Reference/Notes Data Collection and Reporting Numbers ------------------------------------------------------------------------------------------------------- Measuring: Always read between the lines! - always estimate the distance between the smallest scale divisions The ruler on the left has line markings for each centimeter. We can accurately say that the rod is in between 1 and 2 centimeters. Each measurement that we report must contain one digit of estimation. We might estimate that the rod is about 30%-50% beyond the 1-cm mark. Our final recorded measurement might be 1.4 cm, with our estimated digit in the tenths place. The ruler on the right has line markings for each tenth of a centimeter. Because there are more markings on this ruler, we can report our measurement with higher precision. We know for certain that the rod is in between 1.4 and 1.5 cm. Recall, each measurement we report must contain one digit of estimation. Our final measurement recorded from the ruler on the right might be 1.49 cm, with our estimated digit in the hundredths place. ------------------------------------------------------------------------------------------------------- Uncertainty in Measurements: the digit read between the lines is always uncertain (or estimated) ex. 4 is the estimated digit in 1.4 cm (in the example above) ------------------------------------------------------------------------------------------------------- Significant Figures (Sig Figs) Digits of measurements reflect all certain digits and 1 additional estimated (uncertain) digit Significant Figure Rules: 1) All nonzero numbers ex. 23 g 2 63.76 kg 4 2) Captive zeros between 2 nonzero # s ex. 108 ml 3 1000008 cl 7 3) Trailing zeros (after a number, to the right) ONLY when a decimal point is present ex. 20.00 cl 4 23.70 L 4 200 g 1 # s that are NOT significant 1) Trailing zeros (after a number, to the right) ONLY when a decimal point is NOT present ex. 200 g 1 10,800.00 m 7 2) Leading zeros (leftmost) placeholders ex. 0.1230 km 4 0.000070 g 2 ------------------------------------------------------------------------------------------------------- Sig Fig rules ONLY apply to estimated numbers (measurements) Examples of estimated numbers (measurements) ex. 23.76 ml 30.00 g Sig Fig rules DO NOT apply to exact numbers or exact conversions Examples of exact numbers ex. 23 people 23.000000 people Examples of exact conversions ex. 100 cm = 1 m 60 mins = 1 hour -------------------------------------------------------------------------------------------------------
Honors Chemistry Summer Assignment Page 10 Sig Fig rules for addition/subtraction same number as LEAST decimal places or place value (whether it be tens, ones, tenths, hundredths, etc.) ex. 23.46 g + 2.910 g + 6.3 g + 4 g = 36.67 g *0 decimal places in number 37 g Sig Fig rules for multiplication/division same number of LEAST significant figures ex. 63.46 cm x 23.3 cm = 1472.272 cm 2 *Can only have 3 sig figs 1470 cm 2 *These rules apply ONLY when units are common. If units are uncommon, first convert to the common unit (retaining the sig. figs), then perform the math operation following the above rules. ------------------------------------------------------------------------------------------------------- Rounding: ending in 4 or below = round down; ending in 5 or above = round up ex. 54.3 L ~ 54 L 0.0035 kg ~ 0.004 kg ------------------------------------------------------------------------------------------------------- Scientific Notation take into account sig.figs. -For ease of reporting very large or very small numbers, you will need to be able to 1) convert to power of 10- ex. 1,500,000 particles = 1.5 x 10 6 particles and 0.0000250 moles = 2.50 x 10-5 moles 2) And back to decimal form from scientific notationex. 1.3620 x 10-4 L =.00013620 L and 4830 x 10 5 m = 483000000 m ---------------------------------------------------------------------- Arithmetic with units Addition and subtraction: units don't change ex. 2 kg + 3 kg = 5 kg 412 m - 12 m = 400 m However, units must be the same before adding or subtracting ex. 3.001 kg + 112 g = 3.001 kg + 0.112 kg = 3.113 kg Multiplication and division: units multiply & divide too ex. 3 m 3 m = 9 m 2 10 kg 9.8 m/s 2 = 98 kg m/s 2 However, units may cancel ex. 5 g / 10 g = 0.5 (no units!) 10.00 m/s 39.37 in/m = 393.7 in/s ---------------------------------------------------------------------- *For additional help, watch the following links: Measurements and Significant Figures- http://www.youtube.com/watch?v=pfl49nigqf8 Significant Figures Rounding- http://www.youtube.com/watch?v=mz3f8ptznee Significant Figures Calculations- http://www.youtube.com/watch?v=rhillzl-qdw Scientific Notation- http://www.youtube.com/watch?v=gvdsfmrnaqi *For additional examples and practice, watch the following links: Significant Figures Practice- http://www.youtube.com/watch?v=z4yyy_c0414 Significant Figures Calculation Practice- http://www.youtube.com/watch?v=1madkgi9ynk Scientific Notation Practice- http://www.youtube.com/watch?v=jpojhr6i58k
Honors Chemistry Summer Assignment Page 11 Measurement Homework Name 1. a. Using a ruler marked in centimeters, measure and label EACH of the different sides of EACH of the following objects (in cm): (HINT: Make sure you use the correct number of significant figures) b. What does it mean to read between the lines? c. Why is it important to read between the lines? 2. For the following, give the correct measurement. Remember: read between the lines. a. b.
Honors Chemistry Summer Assignment Page 12 o C c. d. 3. a. Underline the digit of estimation in the following measurements: Examples: 14.6325 4.540 x 10-3 1) 8.36 m 4) 0.0000014 cg 2) 7.980 cm 5) 150 cg 3) 1000 ml 6) 18.000 L b. What is a digit of estimation? 4. Circle ONLY each of the following EXACT quantities: 1) 132 people 5) 24.1 cm 2) 76.00 C 6) 24 cm 3) 1000 mg = 1 g 7) 10 dimes 4) 1 mole = 12 g of C 8) 1 dozen egg 5. a. Give the number of significant figures in the following measurements: Examples: 1800300 5.000912 3 8600.10 x 10-4 6 1) 8.3600 m 4) 0.08643920 dl 2) 7.980 cm 5) 0.0908346 Mg 3) 140830 L 6) 0.0000014 cg b. What are significant figures? Why are they important?
Honors Chemistry Summer Assignment Page 13 6. Express the following in scientific notation (exponential form): Examples: 0.000010 1.0 x 10-5 36940 3.694 x 10 4 1) 0.00876 g 3) 0.0000000020 ng 2) 2678000 kg 4) 9346 dg 7. a. Write the following in decimal form: Examples: 1 x 10-5 cm 0.00001 cm 3.694 x 10 4 g 36940 g 1) 2.3 x 10-5 cg 3) 6.0 x 10-8 dg 2) 9.865 x 10 3 g 4) 9.865 x10 4 kg b. Is it always more practical to write numbers using scientific notation? Give an example when it is not. 8. Arithmetic with units: Complete the following unit calculations. Examples: dg + dg = dg cm 3 /cm = cm 2 1) cm x cm x cm = 5) km 3 /km 2 = 2) L x g = 6) ml x L x dl = L ml L 3) cm 3 x g = 7) cl cl = L cm 3 mol 4) g x = 8) particles + particles + particles = g 9. Arithmetic with units and significant figures: Complete the following Examples: 10.12 dg + 205 dg = 215 dg 1523 cm 3 /0.22cm = 6900 cm 2 1) 20.20 km x 0.055 km = 3) 3500.77 m/ 20 s = 2) 50.1 ml 8.76 ml 4) 2010 g 7.88 g =
Honors Chemistry Summer Assignment Page 14 CURRENT EVENT ASSIGNMENT Find a current event related to chemistry and write a summary of that current event. Include the categories listed below in your assignment. The format must include bullets and titles: Topic of current event (must be related to chemistry) Source (staple a copy of the article to the back of your assignment) o Popular Science magazine, MSNBC News online, CNN online, National Geographic magazine, Science Daily, Chemistry Times, etc Summary of current event (at least 5 sentences) o What is this current event discussing? Include important details to help readers understand the topic. Why is this current event important? How does it help society? Citation o Include the MLA citation for the article at the bottom of the page Page requirements o Use 12 pt. Times New Roman font o 1 inch margins o Use proper grammar, spelling, and punctuation o MUST be typed **YOU MUST INCLUDE THE ORIGINAL ARTICLE WITH YOUR CURRENT EVENT. Category: 0 1 2 3 Summary (x2) Grammar, Spelling, Punctuation Format Citations Topic does not relate to chemistry and is not current. Summary is too vague and does not address and describe the topic. There are more than 4 errors. Does not follow format. Not included. Topic does not relate to chemistry or is not current. Provides summary that somewhat addresses and describes topic. There are 3-4 errors. Many errors in MLA citation. Topic relates to chemistry and is current. Provides summary that mostly addresses and describes topic. There are 1-2 errors. Few errors in MLA citation. Topic relates to chemistry and is current. Provides detailed summary that fully addresses and describes topic. There are no errors. Follows format exactly. Correct MLA citation of article.