If you are interested in separating a mixture of volatile compounds, which technique do you think would work best? ○ ICPMS ○ HPLC О АА ○ UV/Vis O LOD GC ○ TLC

analyte concentration(C)(mg/ml) injection volume (ul) elution time (time) peak DAD signal(mAU) caffeine 1 1 4.67 302.85 aspartame 5 1 7.53 15.83 benzoic acid 1 1 8.14 89.98 saccharin 1 1 1.91 84.86 mixture(add everything above with 1:1:1:1 ratio)   1 4.47 69.58 How to get the concentration of the mixture in this case?

5. The color change of a chemical indicator requires an overtitration of 0.03 mL. Calculate the percent relative error if the total volume of titrant is a. 50.00 mL b. 10.00 mL 6. From the Gaussian (normal) error curve, what is the probability that a result from a population lies between 0 and +1 σ of the mean? What is the probability of a result occurring that is between +1 σ and +2σ of the mean?

Gas Chromatography (GC) is one of the useful techniques in analytical chemistry. Give two important components in GC.

Which of the following describes a gradient elution process? stationary phase has varying concentration stationary phase has static concentration mobile phase has varying concentration mobile phase has static concentration

1) Listen The Ksp value for calcium sulfate [CaSO4] is 2.40 X 10-5 and a professor made 1825 mL of a CaSO4(ag) solution but then one of his graduate student accidentally poured in a 0.125 M solution of calcium phosphate [Ca3(PO4)2] solution. You may ignore the additional volume coming from the Cag(PO4)2 solution to make the calculation simpler. Now that you have calculated the new equilibrium constant (K) with this common ion effect then which way will the chemical equilibrium shift? need more information to be determined at equilibrium chemical equilibrium will shift to the right first and then to the left chemical equilibrium will shift to the right chemical equilibrium will shift to the left 201591..docx LAB EXP. #3 -..docx Show All

Which of the following is a possible surface contaminant that can be carried through surface adsorption during precipitation of zinc hydroxide? Select one: NiCO3 (Ksp = 1.3 × 10-7) CaC2O4 (Ksp = 1.7 × 10-9) BaCO3 (Ksp = 5.0 × 10-9) Ba(NO3)2 (Ksp = 4.64 × 10−3)

You work in a research organization that is looking for markers of various diseases that can be used as a diagnostic for the disease. It has been reported in the past that high levels of Cu are found in the sweat of people with cystic fibrosis. One of the research projects is focused on looking for high levels of Cu in samples that can be obtained non-invasively such as saliva, sweat, hair, nails, etc. The lab will analyze large samples for Cu. What instrument would you recommend purchasing to support this work, Atomic absorption spectrophotometer or an inductively coupled plasma atomic spectrophotometer? Explain the basis for your decision.

1-arr In a study of the gas phase decomposition of phosphine at 120 °C PH3(g)- →1/4 P4(g) + 3/2 H2(g) the concentration of PH3 was followed as a function of time. It was found that a graph of In[PH3] versus time in seconds gave a straight line with a slope of -2.50×10² s1 and a y-intercept of -3.24. Based on this plot, the reaction i v O order in PH, and the half life for the reaction is seconds. zero first second

TLC was used to compare the solubility of two compounds A and B in a solvent system (acetic acid, methanol, H2O). The distances that solvent has moved in the silica gel TLC was 12 cm. and for the compounds were 2 and 8 cm respectively. (a) Calculate the Rf values and which compound is more soluble and which one is more polar. (b) What are the factors affecting the Rf value