CHEMISTRY 121
MIDTERM #1B
OCTOBER 25, 2013
2.54 cm = in, 946mL=qt, 454g=lb, 5280 ft = mi, 12in=ft
1. Convert the following measurements into scientific notation and provide the number of
significant figures.
a. 100
b. 101.0
c. 0.01101
d. 45400.0
2. What is the empirical formula of glucose C6H12O6.
3. Give names for the following formulas:
Name the Following
Give Formulas
a. Fe2S3
a. Hypochlorus acid
b. Mn2O7
b. SO3
c. S4N2
c. Hydrogen oxide
d. HCN (aq)
d. Chromium(VI) oxide
e. HCl (g)
e. Carbon tetrachloride
f. H2S (aq)
f. Zinc acetate
4. What does the atomic number tell us about an element?
5. What does the mass number describe about an isotope?
6. What is the difference between an ionic compound and a molecular compound?
7. How many elements are in period 2 of the periodic chart?
8. A compound contains 52.0 % Cr and 48.0% O. Determine the empirical and molecular
formulas if the molar mass is 200.0 g/mole.
9. Give an appropriate unit for each of the following.
a. Time
b. Specific heat
c. Mass
d. Volume
e. Density
f. Energy
10. Convert 72.3 x 10-16 km3 to cm3.
11. Label the following changes as chemical or physical
a. Folding of paper
b. Milk turning sour
c. Magnetizing a piece of steel
d. Healing of a wound
e. Diamonds burning
f. Melting of a diamond
g. Dry ice subliming
12. Find the number of atoms of hydrogen in a 16.2 g sample of glucose C6H12O6.
13. A 1.33 g sample of metal absorbs 2.31 j of heat causing its temperature to increase from
25.0 °C to 33.6°C. Calculate the specific heat of the metal.
14. What mass of water contains the same number of oxygen atoms as a 33.4 g sample of
glucose C6H12O6
15. Mercury has a density of 13.6 g/mL. Find the volume in quarts of 5.00 lbs of mercury.
16. A 5.94 g sample of aluminum oxide contains 3.66 g of Al contains 3.14 g of aluminum.
Give the % composition of this sample of aluminum oxide.