Chemistry
Name:________________________
2.2 Numerical Problem Solving
Date: __________________
SI units/Metric
2. Complete the table:
Quantity
Unit
Unit Symbol
Electric current
ampere
A
length
meter
m
time
second
s
Mass
kilogram
kg
temperature
Kelvin
K
Amount of substance
mole
mol
Luminous Intensity
candela
cd
3. List the units from largest to smallest: meter, millimeter, kilometer, centimeter, picometer.
kilo, meter, centi, milli, pico
Match each quantity to be measured with the most appropriate SI unit.
a.
centimeter
b. gram
c.
Kelvin
d. kilogram
e.
meter
f.
newton
g.
second
e 4. length of swimming pool
a 5. length of a pencil
b 6. mass of a pencil
d 7. mass of a bag of apples
g 8. time between two heartbeats
c 9. temperature of boiling water
f 10. weight of a textbook
Copyright ©by the Glencoe Division of Macmillan/McGraw-hill School Publishing company.
SIGNIFICANT FIGURES
11. For each group of digits indicated in the three numbers below, state whether the digits are
significant. State the rule that applies.
4500.60
0.000799
220
a. yes, digits 1-9 are significant
b. yes, captive zeros are significant
c. yes, digits 1-9 are sig, trailing zeros are significant when the number contians a decimal point
d. no, leading zeroes are not significant
e. yes, digits 1-9 are significant
f. no, trailing zeros are not significant when the number does not contain a decimal point
12. A stack of books contains 10 books, each of which is determined, by a ruler graduated in
centimeters, to be 25.0 cm long. How do these two quantities differ in terms of significant digits?
25.0 cm is a measurement that has 3 sig figs. 10 is a counting number with an “infinite” number
of sig figs. Counts are not measurements so sig figs don’t apply.
Percent Error
13. What is the percent error in a determination that yields a value of 8.38 g/cm3 as the density of
copper? The literature value for this quantity is 8.92 g/cm3.
6.05 %
14. Yusuf measures the melting point of ammonium acetate, NH 4C2H3O2, as 117 ˚C, but the
literature value is 114 ˚C. What is the percent error in the measurement?
2.63 %
Copyright ©by the Glencoe Division of Macmillan/McGraw-hill School Publishing company.
Copyright ©by the Glencoe Division of Macmillan/McGraw-hill School Publishing company.