GENERAL CHEMISTRY I EXAM I

October 1, 2001

INSTRUCTIONS:

PRINT YOUR NAME ————> NAME .

WORK PROBLEM # 1 (5@ 25 pts)

WORK 5 OF #2 THROUGH #8(5@ 25 pts)

TOTAL 150 points

IF YOU WORK MORE THAN 4 OF 3-8, I WILL DROP YOUR LOWEST TWO.

SHOW YOUR WORK FOR PARTIAL CREDIT

USE THE CORRECT NUMBER OF SIGNIFICANT FIGURES

THE LAST TWO PAGES ARE A PERIODIC TABLE AND A SCRATCH SHEET

R = 0.08206 lit•atm/(mol•K)1 .

R = 8.3145 J/mol•K2 .

h = 6.626 X 10-34 J-s3 .

c = 2.9979 X 108 m/s4 .

J = (kg•m2)/s25 .

6 . 7 .

8 .

9 .

TOTAL(150) .

2. How many kilograms (kg) are there in 3.78 short tons. (1 g = 0.03527 oz, 1 lb = 16 oz, 1 short ton = 2000 lb)

3 Isopropanol is the alcohol in rubbing alcohol. The desnsity of isopropanol is 0.7855 g/cm3 at 20 ºC.

a) What is the mas in g of 26.9 mL of isopropanaol at 20 ºC?

b) What is the volume occupied by a sample of isopropanol that has a mass of 15.89 g?

1. Ammonium Nitrate, NH4NO3, is often as a fertilizer because it is a rich source of nitrogen.

a) What is the molar mass of ammonium nitrate?

b) How many moles of are there in 5.89 g of ammonium nitrate?

c) How many individual formula units are there in 5.89 g of ammonium nitrate?

d) How many individual O atoms are there in 5.89 g of ammonium nitrate?

4. Predict the formula of the ionic compound formed from the combination of elements or ions. (For the elements you must use the periodic table to obtain the charge on the ion formed )

a) calcium and nitrogen______

b) sodium and oxygen______

c) magnesium and fluorine______

d) aluminum and nitrate (NO3-)______

e) calcium and sulfate (SO42-)______

f) ammonium and phosphate (PO43-)______

5. Answer the following question using the periodic table. Use the group numbering scheme from the periodic table attached to this test.

a) What is the name on the element with atomic number equal to 17? ______

b) What is the atomic mass in amu of the element Zn ? ______

c) To which period and to which group does the element antimony, symbnol = Sb, belong ?

period______group ______

d) What is the atomic symbol for the alkali metal in period 5? ______

e) Which of the following elements are metals Mg, F, Na, Fe, N and Ar? ______

6. Fill in the missing data of the followng table:

Atomic Symbol / Number of
protons / Number of
neutrons / Number of
eletrons in
neutral atoms / Name of the
Element
a) / 22Ne
b) / 30 / 34
c) / 20 / Chlorine
d) / 31 / 26
e) / 14C

7. Neon has three isotopes with the following masses and abundances:

relative

Isotope mass(amu)abundance (%)

20Ne19.9924 90.48

21Ne 20.9938 0.2702

22Ne 21.9914 9.2498

Determine the atomic mass of iron from this data to 4 significant places.

8. Fill in the missing formula or name for the following compounds.

Do not forget to consider the charges on the ions.

a) sodium sulfide ______

b) magnesium fluoride ______

c) Aluminum nitrate ______

d) ______CaSO4

e) ______(NH4)3PO4

f) ______KClO4