ACS ANALYTICAL CHEMISTRY EXAM
(ACTUAL EXAM) WITH CORRECT ACTUAL
QUESTIONS AND CORRECTLY WELL
DEFINED ANSWERS LATEST ALREADY
GRADED A+ 2025 – 2026
uncertainty - ANSWERS-The range of possible values for a
measurement. can be added or subtracted via squaring each
standard deviation, performing the necessary operations
(+,-) and taking the square root.
relative uncertainty - ANSWERS-Uncertainty of a quantity
divided by the value of the quantity. It is usually expressed
as a percentage of the measured quantity.
multiplying or dividing uncertainty - ANSWERS-use relative
uncertainty. Square, add, then square root. Absolute
uncertainty can be obtained by multiplying by R.
,Binomial Distribution - ANSWERS-The probability
distribution of X with parameters n and p. Homogenous
mixtures.
confidence interval - ANSWERS-a range of values so defined
that there is a specified probability that the value of a
parameter lies within it. Xi = µ ± zσ : Where z is from a table.
degrees of freedom - ANSWERS-The number of individual
scores that can vary without changing the sample mean.
Statistically written as 'N-1' where N represents the number
of subjects.
Normal Phase HPLC - ANSWERS-polar stationary phase, non-
polar mobile phase. Therefore non-polar will come out first,
polar last.
Reverse phase HPLC (High Performance Liquid
Chromatography) - ANSWERS-Non-polar stationary phase,
polar mobile phase. This polar comes out first.
Gradient elution - ANSWERS-Faster separation
, (s2)^2/(s1)^2 (should always be >1)
Use n-1 to find on table.
Fcalc> Ftable -- There is some noise or error
External standard - ANSWERS-use standard solutions
spanning a range of conc, measure response
Internal standard - ANSWERS-substance similar to analyte
(ie deuterated); used to normalize signal by reducing
random error
standard deviation (s) - ANSWERS-the square root of the
variance
% relative standard deviation (%RSD) - ANSWERS-Standard
deviation divided by mean times 100
Grubbs test (Gcalc) - ANSWERS-|Questionable value -
mean/ std dev|
If that is larger than the Gtable value then the value is
thrown out. Locate Gtable value based on number of values
in data set.
(ACTUAL EXAM) WITH CORRECT ACTUAL
QUESTIONS AND CORRECTLY WELL
DEFINED ANSWERS LATEST ALREADY
GRADED A+ 2025 – 2026
uncertainty - ANSWERS-The range of possible values for a
measurement. can be added or subtracted via squaring each
standard deviation, performing the necessary operations
(+,-) and taking the square root.
relative uncertainty - ANSWERS-Uncertainty of a quantity
divided by the value of the quantity. It is usually expressed
as a percentage of the measured quantity.
multiplying or dividing uncertainty - ANSWERS-use relative
uncertainty. Square, add, then square root. Absolute
uncertainty can be obtained by multiplying by R.
,Binomial Distribution - ANSWERS-The probability
distribution of X with parameters n and p. Homogenous
mixtures.
confidence interval - ANSWERS-a range of values so defined
that there is a specified probability that the value of a
parameter lies within it. Xi = µ ± zσ : Where z is from a table.
degrees of freedom - ANSWERS-The number of individual
scores that can vary without changing the sample mean.
Statistically written as 'N-1' where N represents the number
of subjects.
Normal Phase HPLC - ANSWERS-polar stationary phase, non-
polar mobile phase. Therefore non-polar will come out first,
polar last.
Reverse phase HPLC (High Performance Liquid
Chromatography) - ANSWERS-Non-polar stationary phase,
polar mobile phase. This polar comes out first.
Gradient elution - ANSWERS-Faster separation
, (s2)^2/(s1)^2 (should always be >1)
Use n-1 to find on table.
Fcalc> Ftable -- There is some noise or error
External standard - ANSWERS-use standard solutions
spanning a range of conc, measure response
Internal standard - ANSWERS-substance similar to analyte
(ie deuterated); used to normalize signal by reducing
random error
standard deviation (s) - ANSWERS-the square root of the
variance
% relative standard deviation (%RSD) - ANSWERS-Standard
deviation divided by mean times 100
Grubbs test (Gcalc) - ANSWERS-|Questionable value -
mean/ std dev|
If that is larger than the Gtable value then the value is
thrown out. Locate Gtable value based on number of values
in data set.
