MId-term

CHE 145 B5z1 Lab Exam I Name_____________________

Direction: Answer the questions and show your work in the space provided.

1. Convert the following numbers to standard exponential form:

a) 0.00352 _____3.52x10-3__ __ b) 0.01847 _____1.847x10-2____

c) 7,604 ________7.604x103__ _ d) 536.2 x 105 ____5.362x107 _______

2. How many significant figures are there in the following:

a) 0.10849 ________5_________ b) 0.864 _______3_______

c) 6024 _________4________ d) 35.9 x 105 ______3________

3. Add or subtract as indicated. Express to the proper number of significant figures.

a) 15.20 + 0.015 + 6.321 = __21.54__ b) 6.42 + 4.41 - 44 = ___-33___

c) 600 - 107.6 = _____492___ d) 75.2 + 175 - 75.03 = __175___

4. Multiply or Divide the following problems. Round to the correct number of significant figures.

a) (64.69)(8.08) = ______523 ___ b) 0.7406/0.144 = ____5.14_____

c) (354.43)(4.596) = ___ _77.12____ d) 345.67/9.01 = _____38.4_____

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5. Write the names of the chemicals shown by their formulas/or the formulas from the given names.

a) BaCl2 ____barium chloride_____ b) KMnO4 __potasium permanganate

c) H2SO4 ____sulphuric acid______ d) H2O ______hydrogen oxide____

e) AgNO3 ____silver nitrate______

f) Sodium bicarbonate ______Na2CO3____

g) Nitric acid _________HNO3________

h) Hydrochloric acid _________HCl_______

i) Potassium dichromate _______K2CrO4____

j) Sodium hydroxide __________NaOH____

6. Complete the following conversion factors or problems:

a) 1 cm3. = __1___ mL. 1 kg. = _1000___ g. 10 cm. = __100__ mm.

b) Convert 6.54 ft to centimeters:

199.339

c) Convert 100.02 milligrams to pounds: