Problems A
21
EPILOGUE
For many students just starting in chemistry, there is unnecessary frustration
and wasted time because of erroneous or inefficient use of new hand calculators. Learning chemistry is hard enough; lack of skill in using a relatively
simple basic tool only compounds the difficulties. One of the main purposes of
the following problems is to give you practice in correctly and efficiently doing
the principal types of calculations you will deal with in general chemistry. Two
other major types of numerical problems, dealing with reliability of measurements and graphing of data, are discussed in Chapters 5 and 6.
In each of the groups of problems given here you should be able to get the
correct answers rapidly (without making a big intellectual production out of it)
and efficiently (without performing a lot of unnecessary operations or writing
down intermediate figures). Rapidity comes with practice, but correctness and
efficiency may require reading your calculator's instruction manual, or consulting a friend with a calculator similar to yours. Making sure that you can do
these things at the outset definitely will repay you in time saved later and in the
quality of your performance in the course.
PROBLEMS A
1. Simple operations.
(a) 37.237 + 170.04 + 6.404 + 0.395 =
(b) 406,732,465 - 9,357,530,622 =
(c) 76.42 - 37.91 - 53.85 + 28.56 - 94.09 + 22.34 + 6.06 - 40.77 =
(d) 372.375 x 5,287,695.088 =
(e) 0.00000743275 - 4,467,325.62 =
465.1 x 372.7 x 63.2 x 7004.7
(f)
(g)
(h)
518.75 x 892.4
(0.000473)(-72.85) - (21.63)(-0.000625) _
(872.3X-0.0345) - (643.62)(-0.759)
[(27 + 62) + (32 - 57)J[(74 - 49) - (18 + 66)]
[(376 + 422) - (857 - 62)]
2. Reciprocals (use reciprocal key).
(a) 8733 =
(d) 4.093 x 10=
( ) 0.0000362
=
(e) 6.023 x 10
23 ~
(c) 1/4,267,625 =
3. Scientific notation and decimals (integral powers and roots of base 10).
A. Express each of the following in standard scientific notation, and also give
the answer in that notation.
21
EPILOGUE
For many students just starting in chemistry, there is unnecessary frustration
and wasted time because of erroneous or inefficient use of new hand calculators. Learning chemistry is hard enough; lack of skill in using a relatively
simple basic tool only compounds the difficulties. One of the main purposes of
the following problems is to give you practice in correctly and efficiently doing
the principal types of calculations you will deal with in general chemistry. Two
other major types of numerical problems, dealing with reliability of measurements and graphing of data, are discussed in Chapters 5 and 6.
In each of the groups of problems given here you should be able to get the
correct answers rapidly (without making a big intellectual production out of it)
and efficiently (without performing a lot of unnecessary operations or writing
down intermediate figures). Rapidity comes with practice, but correctness and
efficiency may require reading your calculator's instruction manual, or consulting a friend with a calculator similar to yours. Making sure that you can do
these things at the outset definitely will repay you in time saved later and in the
quality of your performance in the course.
PROBLEMS A
1. Simple operations.
(a) 37.237 + 170.04 + 6.404 + 0.395 =
(b) 406,732,465 - 9,357,530,622 =
(c) 76.42 - 37.91 - 53.85 + 28.56 - 94.09 + 22.34 + 6.06 - 40.77 =
(d) 372.375 x 5,287,695.088 =
(e) 0.00000743275 - 4,467,325.62 =
465.1 x 372.7 x 63.2 x 7004.7
(f)
(g)
(h)
518.75 x 892.4
(0.000473)(-72.85) - (21.63)(-0.000625) _
(872.3X-0.0345) - (643.62)(-0.759)
[(27 + 62) + (32 - 57)J[(74 - 49) - (18 + 66)]
[(376 + 422) - (857 - 62)]
2. Reciprocals (use reciprocal key).
(a) 8733 =
(d) 4.093 x 10=
( ) 0.0000362
=
(e) 6.023 x 10
23 ~
(c) 1/4,267,625 =
3. Scientific notation and decimals (integral powers and roots of base 10).
A. Express each of the following in standard scientific notation, and also give
the answer in that notation.