CHE301 Midterm Solved Past Papers

CHE301 MidtErM SolvEd

PaSt PaPErS

Q1. What do you know about pareto diagram?

•Pareto Diagram is a combination of bar and line graphs of accumulated data. It is used where data associated with a problem. The name “Pareto” came from an Italian mathematician who created the diagram

Q2. Name the sources of errors?

Instrumental error, Method error, Human error.

Q3. Goals of sampling?

SampleSize, Sampling types, Samplingtechniques, Samplepreparations, To obtain a mean analyte concentration, Unbiased estimate of the population mean.

Q4. What is limit of quantitation?

Q5. How equipment can be calibrated?

Calibration of an analytical balance using standard weights, Calibration of pipette / micropipettes and other volumetric apparatus to SI units using a calibrated balance, Calibration of pH meter with standard buffers.

Q6. Give the sequence of quality assurance from SI units to products?

Quality AssuranceConsiderations Prior to Method Validation

Q7. Colloidal suspension crystalline suspension?

1-Colloidal suspensions • Particles are invisible to the naked eye (10-7 - 10-4 cm in diameter). • Colloidal particles show no tendency to settle from solution • not easily filtered. 2-Crystalline suspension • particles with dimensions on the order of tenths of a millimeter or greater. • The temporary dispersion of such particles of a tend to settle spontaneously,easily filtered.

Q8. What is error?

Error simply means not correct. But mathematically it may have some other meanings as well.

Q9. Types of sampling?

There are two major types of sampling Probability and Non-probability,which are further divided into sub types.

Q10. What factors needed for instrumental technique?

The instrumentshould be calibrated. Should follow properstandard operating procedure and standard testing methods. Instrumentshould be installed,operated and performedaccording to standard specifications. And the last but not least is statisticalevaluation of analytical data.

Q11. Molarity?

Molarity is the concentration of a particular chemical species. Formality, on the other hand, is a substance’s total concentration without regard to its specific chemical form.

Q12. Method validation?

Q13. Use of uv spectroscopy?

•UV SpectroscopyTo find wavelength, To estimate concentration of unknown in sample.

Q14. Use of Nmr Spectroscopy and mass spectrometry?

•  NMR spectroscopy- On basis of magnetic properties define certain nuclei.
•  Mass Spectrometry- Used to evaluate mass of separated molecules, Used as a detector.

Q15. what is beer lambert law?

Beer Lambert Law: A=log10 Io/I = E/c I0 = Incident light, I = Transmitted light, l = path length, C = Concentration,  = Molar AbsorptivityConstant Allthe spectroscopic techniques use certainkindof electromagnetic radiationsand are based on Beer Lambert law.

Q16. Name two basic types of hypothesis?

Hypothesis type •Null HypothesisH0, •Alternate Hypothesis-Ha

Q17. what is standard deviation?

Standard deviation (the measure of precision), Reporting of data-Significant figures, Treating significant figures in calculations, Rounding off data, Confidence Interval, CV and SEM.

Q18. what is limit of quantitation?

Limit of Quantitation (LOQ): • It is the lowest concentration of an analyte in a sample that may be determined with acceptable accuracy and precision.

Q19. what is sample preparation?

Sample preparation Toanalyse we have to digest or extract our analyte from the sample. This is called sample preparation.