Analytical chemistry ACS Exam Questions with Verified
Answers.
E relative - ANS (|x1-x(true)|)/x(true) *100
standard deviation - ANS sqrt((x1-x)^(2)+(x2-x)^(2))/(n-1)
relative standard deviation - ANS (s/x(mean))*100
relative uncertainty - ANS (abs uncertainty)/measured value
How are vol pipets calibrated? - ANS For last drop to not be forced out
TC - ANS to contain
TD - ANS to deliver
Tolerance - ANS max permissible deviation of measured value
propagation of uncertainty add or sub - ANS sqrt(x^(2)+x2^(2)......)
propagation on uncertainty multiplication or subtraction - ANS sqrt((x/a)^(2)+(x/b)^(2))
for gaussian curve +2 sigma is.... - ANS 68.2%
for gaussian curve what is +3 sigma.... - ANS 99.7%
Qcalc - ANS (gap)/(range)
Grubbs test - ANS |mean-poss outlier|/s
uncertainty - ANS mu=mean+/- ts/SQrt(N)
S pooled - ANS sqrt((Na-1)sa^(2)+(Nb-1)sb^(2))/(Na+Nb-2)
tcalc - ANS
Least sq method - ANS The best fit line through a set of data points in which the line
which min the sum of sq of deviations between data points and lines.
linear range - ANS conc range of analyte over which linear detector is linearly
proportional
Sensativity - ANS slope of linear portion of a/b curve
, min det limit - ANS 3s/m
lim of quant - ANS 10s/m
internal calibration - ANS carried out through the method of standard additions. Known
analyte.
method of standard additions - ANS accounts for matrix effects. Calibration occurs
within the sample matrix
multi-point standard addition - ANS 4-5 id clean and dry vol flasks obtained. Volume of
sample added to each flask. Next variable amounts of standard solution spiked in each
flask.
Requirements of Internal standard - ANS 1. Must produce a response easily
distinguishable from analyte
2. Should be chemically similar
3. should be chemically stable
equilibrium point - ANS when analyte is consumed by reaction
direct titration - ANS when all the titration is added till all the analyte is consumed by
reaction
back titration - ANS analyst prep adds a known quantity of standard reagent in excess
to consume all analyte, then titrated back to eq
endpoint - ANS the point in a titration where the indicator changes color
requirements of primary standards - ANS 1. Should be stable
2. should not be hydroscopic
3. should be stable when heated
4. high molecular weight
molamity - ANS moles of sol/ kg of sol
common ion - ANS suppresses dissulation
bronsted lowry acids - ANS donate protons
Brinsted-Lowry base - ANS accept protons
Ka=kw/kb - ANS
Ka rules - ANS 1. Ka1 will always be bigger than Ka2
2. The inc in H from first proton donation supplies further reaction donation
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Lectjoe. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $25.49. You're not tied to anything after your purchase.
