In paper chromatography, why must the starting line be drawn with a pencil? Briefly explain why adding acetic acid to a developing solution during chromatography tends to eliminate "steaks" on the TLC plate that are frequently observed in non-acidified solutions. ...
Explain why standard solutions are prepared for volumetric analysis. Explain, why it is necessary to cap the burette and minimize CO_2 absorption from air by the NaOH solution. How would this affect your results? Is the indicator typically...
Why is 2-methylheptane achiral? Why are all of the solutions used in this experiment 1.0 x 10-1M in HNO3? Why are termolecular steps infrequently seen in chemical reactions? Why is CH4 not capable of forming hydrogen bonds? In step (IV) why does the solution have to be cooled? I know...
In a titration of a standardized NaOH solution with an unknown acid solution, what assumption would have to be made in order to calculate the concentration of the acid solution? (Write this in the for What is the equivalence point o...
Why must NaOH be standardized? What is the purpose of hydrogen peroxide in the cobalt complex lab ? Explain why oxalic acid is stronger than Malonic acid for the first deprotonation. Why was Mendeleev's periodic table rejected? Why is quantum theory required to explain the nature of ...
Lying beside the test tubes are three labels: 0.10 M K2CO3, 0.10 M H2SO4, and 0.10 M NaOH. You are to place the labels on the test tubes using only the three solutions. Here are your tests Ten drops of water are added to two small test tubes and...
Solutions containing the virus, with a density of about 1.3 g/mL in the case of TMV, are layered on top of the gradient, and the virus particles are centrifuged into the gradient for 1–3 h, depending on centrifugal force. As the density of the gradient material is lower than that of...