1|Page
ACS Analytical Chemistry Final Exam Latest 2025 Actual
Questions and Verified Answers () A+ Grade
100% Guarantee Verified by Experts
Systematic Error ......ANSWER......-repeated measurements are usually
always high or always low
-can and should be corrected for
Relative uncertainty= ......ANSWER......absolute uncertainty/magnitude
of measurement
68% of measurements in a Gaussian Curve will lie
......ANSWER......between the mean-1 and the mean+1
Variance in standard deviation ......ANSWER......standard deviation
squared
mean= ......ANSWER......true value +-time*standard deviation
T-test Case 1 ......ANSWER......measure sample of known composition
pg. 1
,2|Page
T-test case 2 ......ANSWER......compare replicate measurement of an
unknown sample
T-test case 3 ......ANSWER......compare individual difference of an
unknown sample
- two sets of data analyzed by both methods being used
T-test case 1 equation ......ANSWER......true value= mean (+-)
(time*standard deviation)/sqrt(number of measurements))
T-test case 1 Tcalc= ......ANSWER......(sqrt(n)Iknown value-calculated
meanI)/standard deviation
For Case 1:
If Tcalc>Ttable ......ANSWER......the actual value isn't in the range and it
is bad
For Case 1:
If Tcalc<Ttable ......ANSWER......the actual value is close to our
calculated value
For Case 2:
you need to first solve for Fcalc= ......ANSWER......(larger standard
deviation)^2/(smaller standard deviation)^2
pg. 2
, 3|Page
If Fcalc<Ftable, you should use ......ANSWER......Case 2A
If Fcalc>Ftable, you should use ......ANSWER......Case 2B
T-Test Case 2A: Tcalc= ......ANSWER......(Icalculated mean 1-calculated
mean 2I/spooled)*sqrt((n1*n2)/(n1+n2))
For Case 2A:
if Tcalc < Ttable, then ......ANSWER......the two sets of data are
statistically indistinguishable
For Case 2A:
spooled(standard deviation pooled)= ......ANSWER......sqrt((s1^2(n1-
1)+s2^2(n2-1))/(n1+n2-2))
where s=standard deviation and n=number of measurements
For Case 2B:
Tcalc= ......ANSWER......(Icalculated mean 1-calculated mean
2I)/sqrt((s1^2/n1)+(s2^2/n2))
For case 2B:
pg. 3
ACS Analytical Chemistry Final Exam Latest 2025 Actual
Questions and Verified Answers () A+ Grade
100% Guarantee Verified by Experts
Systematic Error ......ANSWER......-repeated measurements are usually
always high or always low
-can and should be corrected for
Relative uncertainty= ......ANSWER......absolute uncertainty/magnitude
of measurement
68% of measurements in a Gaussian Curve will lie
......ANSWER......between the mean-1 and the mean+1
Variance in standard deviation ......ANSWER......standard deviation
squared
mean= ......ANSWER......true value +-time*standard deviation
T-test Case 1 ......ANSWER......measure sample of known composition
pg. 1
,2|Page
T-test case 2 ......ANSWER......compare replicate measurement of an
unknown sample
T-test case 3 ......ANSWER......compare individual difference of an
unknown sample
- two sets of data analyzed by both methods being used
T-test case 1 equation ......ANSWER......true value= mean (+-)
(time*standard deviation)/sqrt(number of measurements))
T-test case 1 Tcalc= ......ANSWER......(sqrt(n)Iknown value-calculated
meanI)/standard deviation
For Case 1:
If Tcalc>Ttable ......ANSWER......the actual value isn't in the range and it
is bad
For Case 1:
If Tcalc<Ttable ......ANSWER......the actual value is close to our
calculated value
For Case 2:
you need to first solve for Fcalc= ......ANSWER......(larger standard
deviation)^2/(smaller standard deviation)^2
pg. 2
, 3|Page
If Fcalc<Ftable, you should use ......ANSWER......Case 2A
If Fcalc>Ftable, you should use ......ANSWER......Case 2B
T-Test Case 2A: Tcalc= ......ANSWER......(Icalculated mean 1-calculated
mean 2I/spooled)*sqrt((n1*n2)/(n1+n2))
For Case 2A:
if Tcalc < Ttable, then ......ANSWER......the two sets of data are
statistically indistinguishable
For Case 2A:
spooled(standard deviation pooled)= ......ANSWER......sqrt((s1^2(n1-
1)+s2^2(n2-1))/(n1+n2-2))
where s=standard deviation and n=number of measurements
For Case 2B:
Tcalc= ......ANSWER......(Icalculated mean 1-calculated mean
2I)/sqrt((s1^2/n1)+(s2^2/n2))
For case 2B:
pg. 3
