The solvent diethyl ether can be mixed with water but only by shaking the two liquids together. After the shaking is stopped, the liquids separate into two layers, much like oil and vinegar.
The free-base form of the alkaloid caffeine is readily soluble in diethyl ether but not in water. Suggest what might happen to the caffeine of a caffeinated beverage if the beverage was first made alkaline with sodium hydroxide and then shaken with some diethyl ether. A) The water layer would turn a pink color indicating an alkaline pH.
B) The caffeine would transform into the free base and become more soluble in the diethyl ether.
C) The caffeine would transform into the free acid and transfer into the diethyl ether.
D) The diethyl ether and water would mix into one layer.
Question 2
Would formulating a sulfa drug with PABA be likely to increase or decrease its antibacterial properties?
A) There would likely be an increase in antibacterial properties due to the synergistic effect of these two agents working together.
B) A sulfa drug and PABA combine in the body to form highly active forms of penicillin, which is a powerful antibiotic.
C) No, but the combination would prove effective against viruses.
D) There would likely be a decrease in antibacterial properties because a sulfa drug works by competing with PABA
The relationship between air temperature and two measures of water vapour saturation of air.
Properties of Water
Water Solubility of Selected Chemicals
The structure of liquid water
Lineweaver–Burk plot for mixed inhibition kinetics
Water shortages, reduced agricultural capacity & coastal inundation are common themes