it is an error analysis HW

Lecture
problem
worth
2%
of
your
final
grade.
Attach
all
excel
plots.
Show
all
work
for
credit.





1) A
and
B
react
according
to
the
scheme
2A +B → C .
The
reaction
is
highly
exergonic,
that
is,

it
goes
to
completion
when
A
and
B
are
allowed
to
react.
2.000
tons
of
A
and
1.00
ton
of
B
were
mixed
in

a
kettle.
A
balance,
the
maximum
capacity
of
which
is
0.500
tons
with
1%
precision
was
used
to
weigh
A

and
B.
Assume
that
the
molar
masses
of
all
chemical
species
are
equal.

What
is
the
maximum
possible

amount
of
unreacted
reactants?




2) An
experiment
is
performed
to
determine
the
force
constant
k
of
a
spring
by
measuring
its

length
as
a
function
of
the
applied
load.
The
following
data
are
obtained:




Mass
(g)

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0


Length
(cm)

5.1

8.8

10.9

14.3

18.0

20.56

23.94

26.94

30.92

33.91

























Mass
(g)

110.0

120.0

130.0

140.0

150.0

160.0

170.0

180.0

190.0

200.0


Length
(cm)

36.57

38.57

43.55

46.88

49.01

52.20

54.19

58.52

61.84

64.50





Report
the
values
of
L0
(initial
length)
and
k
(force
constant)
and
their
associated
uncertainties

with
95%
confidence
limit.




3) Each
student
measured
the
lengths
of
a
pencil
using
calipers.
Record
and
combine
your
data

into
one
table.
Calculate
the
average
value
for
the
length
of
the
pencil.
Calculate
the
standard
deviation.






4) From
the
data
below
calculate
the
viscometer
constant
for
716L
viscometer
(the
viscometer

constant
is
the
hypothetical
time
required
for
water
to
flow
through
viscometer
capillary).
Water
was

used
to
calibrate
100
viscometer,
which
was
in
turn
used
to
find
the
viscosity
of
liquid
1.
Then,
liquid
1

was
used
to
calibrate
200
viscometer,
which
was
used
to
determine
the
viscosity
of
liquid
2,
and
so

!!

forth.

Use
the
equation


!!

=

!!
!!


for
the
calculations.




Refer
to
the
“Helpful
Simplifications”
section
in
the
Lab
Manual
appendix.
A
more
thorough

introduction
to
uncertainty
analysis
can
be
found
in
chapter
2
of
the
Shoemaker
text
mentioned
in
the

syllabus.
Additional
information
on
equilibria
of
gases
and
related
equations
can
be
found
in
chapter
1

of
the
lab
manual.


Viscometer


sample


100(T472)


H2O


200(M763)


Liquid
1


Liquid
2

350(716L)











time
(s)
sample
time
(s)

70.35

374.72

70.18

373.93

70.22

373.65

70.31
Liquid
1
373.47

70.25

373.62

70.30

373.82

70.32

375.13

57.75

319.78

57.66

319.71

57.78

319.75

57.87
Liquid
2
319.65

57.65

319.78

57.75

319.69

57.81

60.47



60.40

60.44

60.43

60.37

60.44

60.47


















319.75