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# Experimental Design and Methods in Chemistry

### Percent Composition: Gas chromatographic analysis of a mixture of organic compounds gave the following peak areas.

Gas chromatographic analysis of a mixture of organic compounds gave the following peak areas (sq cm): hexane = 2.7, heptane 1.6, hexanol = 1.8, toluene = 0.5 a. Calculate the mole percent composition of the mixture. Assume that the response of the detector (area per mole) is the same for each component. b. Calculate the

### Relative Retention

Retention times for several organic compounds separated on a gas chromographic column are given below: Compound tR(seconds) Air 75 Pentane 190 Heptane 350 2-Pentene 275 a. Calculate the relative retention of 2-Pentene with respect t

### Mass Density of Certain Volume

The mass of a certain volume of an unknown liquid at 25 degrees Celsius was determined to be 24 mg. The mass of an equal volume of water at the same temperature was measured as 201 mg. Calculate the density of the unknown liquid at 25 degrees Celsius.

### Laboratory Questions

A laboratory has four hoods each of which is 39 inches wide. When the hood door is open to a height of 8 inches and the hoods are operating, the average air velocity through the hood is 170ft/min. a. Evaluate the total ventilation rate for this room assuming that there are no other exhausts. b. The laboratory is designed for

### Calculating Absorptivity

I have tried to play with all the numbers in this question, but nothing seems to be working. Nitrite ion, NO-2 is used as a preservative for bacon and other foods. It has been the center of controversy since it is potentially carcinogenic. Here is an abbreviated procedure for the determination: Step 1: 50.0 mL of unk

BRAINMASS PROBLEM 10 Please describe the following terms: 1) Larmor Frequency 2) Nuclear Overhauser Effect 3) 180° Pulse 4) Spin Lattice relaxation 5) Free Induction Decay

### Understanding Beer's Law

What is Beer's law? Use Beer's law to mathematically determine the unknown concentration values. How do the values derived from Beer's law compare to those derived from the graph?

### Identifying Potassium Bromide in a Solution without an Indicator

Is there a chemical test to see if the solution has potassium bromide without using an indicator and what is the chemical equation for it?

### Identifying different solutions.

If I had 5 solutions that are not labeled (the solutions are ethanoic acid, calcium hydroxide, potassium bromide, sodium chloride and nitric acid) is there a way of identifying which one is which without using an indicator?

### Is there a chemical test to see if a solution has nitric acid without using an indicator?

Is there a chemical test to see if a solution has nitric acid without using an indicator?

### Gaussian Theory for Elasticity Compared to Experiments

How does Gaussian theory for elasticity compare to actual experiments (in compression and tension), and why?