1. http://teachers.yourhomework.com/blowe/1 Today's Agenda.t 1/18/11 Recall 1 Get your comp books out before the bell rings Start Semester Review Pass out semester review Start studying for the Chem department final which will be on Monday January 24, 2011. There will be another class final as well. Make sure to have a good book to read and pass time. 12/3/2015

2. Chemistry Department Final The Chemitry department final is on Monday January 24 th. There will be an additional Chem test on your “final” day based on material this semester. 12/3/2015

3. Recall Moles (mol) Mass (g) Molar Mass (g/mpl) 12/3/2015 N 2 H 2 NH 3 14.01+ 3(1.008) =17.034 2(1.008) =2.016 2(14.01) =28.02 6.78.24.72 x 2.016 = 1.45.48 x 17.034 = 8.18 6.78 g of N 2 N 2 + 3H 2  2 NH 3

4. Recall 2 Find the mole ratios in: 2Al + 6HCl  2AlCl 3 + 3H 2 1.From HCl to H 2 2.From Al to AlCl 3 3.From H 2 to HCl 4.From AlCl 3 to H 2 12/3/2015 3/6 2/2 6/3 3/2

5. Scientific Notation When the number is Big Leave one number in front of the decimal point and count how many steps you took to get there. Then times that number by 10 to the power of the (+) number of steps to get there. 7,980,000  7.98 x 10 + When the number is Small Leave one number in front of the decimal point and count how many steps you took to get there. Then times that number by 10 to the power of the (-) number of steps to get there. 0.000026  2.6 x 10 - 12/3/2015 From Standard to Scientific

6. Scientific Notation Look at the exponent on 10 If the exponent is positive (+), then move the decimal point that # of steps to the right. Put in zeros where there are no numbers ex. 6.7 x 10 3 m = 6700 m If the exponent is negative (-), then move the decimal point that # of steps to the left and place zeros as place holders. Ex. 3.4 x 10 -5 g = 0.000034 g From Scientific to Standard

7. Metric Conversions Remember the prefixes for the metric system. The most used are: μ micro 10 -6 m milli 10 -3 c centi 10 -2 k kilo 10 3 12/3/2015 Example: 5 cm = ? m 5 x 10 -2 m = 0.05 m 2400 mg = ? kg 2400 x 10 -3 g = ? 10 3 g 2400 x 10 -3 /10 3 kg 2400 x 10 -6 kg =.0024 kg

8. Metric Conversions There are many different ways to do metric conversions. Find the one that you like the most and stick with it. Remember the step method. What you have divided by what you need. 12/3/2015

9. Temperature Conversions To Fahrenheit from Celsius F = C x (9/5) + 32 Example: What is 32°C in °F? F = 32 x (9/5) + 32 F = 57.6 + 32 F = 89.6°F To Celsius from Fahrenheit C = (F - 32) x (5/9) Example: What is 75°F in °C? C = (75 - 32) x (5/9) C = (43) x (5/9) C = 23.9°C 12/3/2015

10. Temperature Conversions to Kelvin To Kelvin from Celsius K = C + 273 Example: What is 32°C in K? K = 32 + 273 K = 305 K To Celsius from Kelven C = K - 273 Example: What is 50 K in °C? C = 50 – 273 C = -223°C 12/3/2015 Always change from Fahrenheit to Celsius then to Kelvin

11. Dimensional analysis Volume = How much space something takes up Mass = How much something weighs Density = Mass/Volume Example: A block of Aluminum is 3 cm x 4 cm x 5 cm and has the density of 2.7 g/cm 3. What is the mass of this block? Volume is 3 x 4 x 5 = 60 cm 3 Mass = Density x volume Mass = 2.7 g/cm 3 x 60 cm 3 = 162 g

12. Dimensional analysis Graduated cylinders can be used to find the volume of an object. Volume = Final measurement – Initial measurement Example: A graduated cylinder first measures 40 mL. After an object is dropped in it then reads 62 mL. What is the volume of the object? V= 62 – 40 = 22 mL BTW mL = cm 3

13. Homework Begin to start reviewing for the semester final Some strategies that may help: Read over your notebook Try and find the chapters in the book that correspond to your notes and practice questions. Go over recalls and examples in your notebook Take time to memorize names like the difference between Nitrate and Nitride! http://teachers.yourhomework.com/blowe/13 12/3/2015