C.P. Chemistry Test 2. Study Guide. Measurement and Calculations

Transcription

1 C.P. Chemistry Test 2 Study Guide Measurement and Calculations Define SI base units for time, length, mass, and temperature. Express numbers in scientific notation. Use factor label method to convert between units. Distinguish between accurate and precise data. Record data with the correct number of significant figures. Count the number of significant figures in a measurement. Convert units between Celsius and Kelvin temperature units. Use percent error to describe the accuracy of experimental data. Create and analyze graphed data. 1

2 CP Chemistry Review Sheet Measurement Name Date Pd. All of the answers are given, in random order, after each section. Please check your answers and be sure you are doing all of your work correctly. This assignment will be collected and graded. A. Scientific Notation 1. Convert the following into scientific notation: a = b. 123 = c = d = 2. Convert the following into decimal notation (ordinary notation): a x 10 3 = b. 5 x 10 2 = c. 280 x 10-4 = d x 10-5 = A Answers: x x x x B. Metric Units 3. Fill in each of the blanks with an appropriate unit: mm, cm, m, km, mg, g, kg, ml, L, kl a. Judy weighed her pen before and after class and found she had used 1.5 of ink. (mass) b. The empty fish tank weight about 7, and it could hold 43 of water. c. The steak I had was huge! It was about 3 thick and must have weighed at least 800. d. The anchored hot air balloon was about 35 tall and held about 720 of air. e. The slot was just 1 too short for the dime to pass through. f. The standard archery arrow is 0.85 in diameter, 0.72 long and in mass. g. It takes about 2 of cayenne pepper on your tongue to make your mouth feel like it's on fire. h. The 65 man was so thirsty after running 13 that he drank 1500 of water. B Answers: mm cm cm m m km mg mg g kg kg kg ml L kl C. Sig Figs 4. For the following measurements, indicate how many significant figures there are: a) 34 g b) 504 L c) 3.4 x 10 3 g d) mg e) 101 km f) 7.0 x 10-5 mm g) 5040 L h) mm i) 20 mg j) 20. km k) 20.0 g l) 0.02 L C Answers for #4: 1,1,2,2,2,2,3,3,3,3,3,4 5. Round each of the following off to the specified number of sig fig's: (some have been done for you...) a) Round g to... 4 sig figs: sig figs: 2 sig figs: b) Round g to... 4 sig figs: 3 sig figs: sig fig: c) Round g to... 4 sig figs: 3 sig figs: 2 sig figs: 370 2

3 d) Round 50,001 g to... 4 sig figs: 3 sig figs: _5.00x sig fig: C Answers for #5: , x Perform all calculations and express your answer with the appropriate sig figs & units: a) 67 cm x 55 cm = 3700 cm 2 b) 4.29 m x 9.8 m = c) 870 mm x 430 mm = d) g/l x 8.8 L = e) m x 6.39 m = f) 3.56 cm x 2.45 cm x 0.83 cm = g) 45.9 mi 1.50 hr = h) (4.6x10 7 m) x (7.32x10-3 m) = i) (4.6x10 7 g) / (7.32x10-3 cm 3 ) = j) 3.56 g (2.6 cm x 4.3 cm x 7.8 cm) = 7) Perform all calculations & give your answers with the appropriate units and sig figs. a) 6.74 g g = b) 1200 kg kg = c) s s = d) 7800 cm - 2 cm = e) m - 2 m = 782m f) 2.54 g g = 8) Show your work for all of the following calculations. Remember units and sig figs. a) A box is cm by 45.2 cm by 7.9 cm. Its volume (V = l x w x h) is: b) A 934 g cat ate a 82.4 g rat, and then coughed up a g hair ball. The cat now weighs: c) A 5627 g brick measures 5.60 cm x 4.51 cm x cm. Its density (D=m/V) is: d) A g stone is place in a grad. cylinder, and the liquid level rises from 25.7 ml to 32.6 ml. Determine the stone s volume (Hint: subtract to find the volume of the water displacement): Determine the stone's density: (hint: Density = mass volume displacement) C Answers for #6 8: 8.8g 7798 cm 1013 g 0.30g 7.2 cm ml 1486 kg 42 m g/cm 3 6.6g/mL 9.02 g/cm 3 8.4x10 4 cm g 17.6 s 3.4x10 5 m 2 6.3x10 9 g/cm mi/h 370,000mm m 2 3

4 D. Dimensional Analysis (Factor/Label Method) 9. Convert the following. Show all work!!! Example 1: Change 29.5 in to ft: 29.5 in x 1 ft = 2.46 ft. 12 in a) Change 2.45 ft to mi b) Change 75.0 kg to lb c) Change 10.0 gal to ml Example 2: Change 5.17 lb/gal to lb/qt: 5.17 lb x 1 gal = 1.29 lb/qt gal 4 qt d) Change km/hr to ft/hr Example 3: Change 527 mi/h to m/s 527 mi x 1.61 km x 1000 m x 1 h x 1 min = 236 m/s h 1 mi 1 km 60 min 60 sec e) Change 459 ft/sec to mi/hr 4

5 Example 4: Change 3.9 cm 3 to mm cm 3 x 10 mm 3 = 1 cm 3.9 cm 3 x 1000 mm 3 = 3900 mm 3 1 cm 3 f) Change 5800 mi 2 to km 2 D Answers 1.068x105 ft/h 165 lb 4.55x10-4 mi 313 mi/h 15,000 km x10 4 ml E. Periodic Table. There is a periodic table in your planner on page Complete the following table by filling in the correct symbol or word. Spelling counts. 5

6 F. Density and Percent Error ( Percent Error = Actual Accepted x 100% ) Accepted 11) An object with a mass of 7.5g raises the level of water in a graduated cylinder from 25.1mL to 30.1mL. What is the density of the object? 12) The density of aluminum is 2.7g/mL. What is the volume of 8.1g? 13) The accepted density for aluminum is 2.7g/ml. Calculate the percent error if your result was 3.3g/ml. 14) The accepted length of a piece of wire is 6.54m. You measure 4.60 m. What is the percent error? F Answers: 22% -29.7% 1.5 g/ml 3mL 6