1. REVIEW AND PRACTICE
CHEMISTRY UNIT 2 EXAM

2. The density of gold is 19. 3 g/cm3
The density of gold is 19.3 g/cm3. What is the mass of a gold nugget that has a volume of 3.6 cm3?

3. The nearest In and Out is 2. 75 miles from school
The nearest In and Out is 2.75 miles from school. How far away from school are the shakes and fries in millimeters?

4. 56.95 ml – 2.7 ml
Give answer with correct units and sig figs

5. 127.1 cm cm cm =
Give answer with correct units and sig figs

6. 1.234 x 10-8 cm x x 1014 cm

7. 1.234 x 10-8 cm divided by x 1014 cm

8. The speed limit on the streets surrounding Tam High is 25 miles per hour. How fast is this in cm/minute? (1 mile = 1600 m)

9. The scale in PE class measures your weight at 152 pounds
The scale in PE class measures your weight at 152 pounds. Your theoretical weight is 148 pounds. What is the percent error of the scale?

10. What is the mass percent of sodium in NaCl?

11. How many moles of Au are in 1.23 x 1045 atoms of Au?

12. How many moles of Au are in 5.67 x 108 g of Au?

13. How many atoms of N are in 156.3 g of N?

14. How many atoms of H are in 183 g of water?

15. Styrofoam is 92. 25% C and 7. 75% H and has a molar mass of 104 g/mole
Styrofoam is 92.25% C and 7.75% H and has a molar mass of 104 g/mole. What is the empirical formula of Styrofoam? What is the molecular formula of Styrofoam?

16. Ibuprofen (Advil) has molar mass of 206 g/mole and is 75. 7% C, 8
Ibuprofen (Advil) has molar mass of 206 g/mole and is 75.7% C, 8.80% H and 15.5% O. What is its molecular formula?

17. How many atoms of each element are present in one molecule of H3PO4?

18. Room temperature is about 21 degrees Celsius
Room temperature is about 21 degrees Celsius. What is this temperature in Kelvins?

19. Round to five sig figs

20. How many sig figs in ?
In 102,300?
In ?

21. What is the difference between accuracy and precision?

22. Which tool, flask, cylinder or beaker, is best for measuring volume of a liquid?