1. CHEMISTRY-CP MIDTERM PROBLEM REVIEW

2. QUESTION 1 Write 0.0005321 in scientific notation. Answers to problem Midterm Math Review Sheet #1 3.54 x 10 -3 4.5 x 10 5

3. QUESTION 2 Write 2.33 x 10 5 in regular notation. Answers to problem Midterm Math Review Sheet #1 107000 0.0069

4. QUESTION 2 How many grams in 0.32 kilograms? Answers to problem Midterm Math Review Sheet #2 6000 g0.5 s

5. QUESTION 4 How many significant digits are in the following measurement: 0.0230430 grams Answers to problem Midterm Math Review Sheet #3 0.00560 = 35090. = 4400 = 16.00 x 10 2 = 3

6. QUESTION 5 Calculate the answer to this problem & express it to the proper # of sig figs. 501.2 x 623.2 x 2.10 x 0.0050 Answers to problem Midterm Math Review Sheet #4 194x10 5 (or 400000)460 (or 4.6x10 2 ) 7.7 x 10 -4

7. QUESTION 6 A piece of metal has the following dimensions: length = 1.25 cm; width = 1.00 cm; height = 2.34 cm. The mass of the metal is 26.2 g. What is the density of the metal? Answers to problem Midterm Math Review Sheet #5 0.5 g/mL0.06 g

8. QUESTION 6 What is the molar mass of Mg(OH) 2 ? Answers to problem Midterm Math Review Sheet #6 44.01 g/mol179.87 g/mol96.11 g/mol249.72 g/mol

9. QUESTION 7 What is the percent composition by mass of oxygen in AlPO 4 ? Answers to problem Midterm Math Review Sheet #7 11.2% H & 88.8% O39.8% Cu, 20.1% S, 40.1% O82.2% N & 17.8% H

10. QUESTION 8 How many grams of water are in 22.0 g of MgCl 2 *2H 2 O? Answers to problem Midterm Math Review Sheet #7 3.6 g H 2 O

11. QUESTION 9 1,6-diaminohexane is used to make nylon. What is the empirical formula of this compound if it is 62.1% C, 13.8% H and 24.1% N? Answers to problem Midterm Math Review Sheet #8 CaCl 2 CeI 3

12. QUESTION 10 What is the molecular formula of ethylene glycol, antifreeze, if its molar mass is 62 g/mol and its empirical formula is CH 3 O? Answers to problem Midterm Math Review Sheet #8 N 2 H 4

13. QUESTION 11 How many moles are in 123 grams of lead (IV) chloride?

14. QUESTION 12 How many formula units are in 22.3 grams of magnesium hydroxide? Answers to problem Midterm Math Review Sheet #9 (w/ proper sig figs) 30 g CH 4 1.32 x 10 24 molecules H 2 O1.99 mol N 1.20 x 10 24 atoms Ne6 mol SO 3 4110 g U

15. QUESTION 12 How many formula units are in 22.3 grams of magnesium hydroxide? Answers to problem Midterm Math Review Sheet #9 (w/ proper sig figs) 30 g CH 4 1.20 x 10 24 atoms Ne 1.32 x 10 24 molecules H 2 O 6 mol SO 3 1.99 mol N4110 g U

16. QUESTION 13 According to this equation: 2Na 3 PO 4 + 3BaCl 2  Ba 3 (PO 4 ) 2 + 6NaCl How many moles of barium chloride are necessary to produce 1.25 moles of barium phosphate? Answers to problem Midterm Math Review Sheet #10 (w/ proper sig figs) 5.0 mol C & 2.5 mol O 2

17. QUESTION 14 Lithium nitride reacts with water to form ammonia and aqueous lithium hydroxide. Li 3 N + 3H 2 O  NH 3 + 3LiOH What mass of water is needed to react with 32.9 g Li 3 N? Answers to problem Midterm Math Review Sheet #10 (w/ proper sig figs) 0.277 g H 2 & 9.72 g Cl 2

18. QUESTION 15 Calculate the molarity of a solution containing 400 g CuSO 4 in 4.00 L of solution? Answers to problem Midterm Math Review Sheet #11 (w/ proper sig figs) 0.5 M0.1 M56 g25.5 g

19. QUESTION 16 A technician experimentally determined the boiling point of octane to be 124.1  C. The actual boiling point of octane is 125.7  C. Calculate the percent error. Answers to problem Midterm Math Review Sheet #12 (w/ proper sig figs) 70.% yield30.% error

20. QUESTION 1