Size exclusion chromatography is a good technique for separating proteins based on size due to tiny pores in the beads in the column (the smaller proteins will elute out last). Cation exchange chromatography is a good technique for separating proteins based on charge due to negatively charged beads in the column (the positively charged molecules will elute out last). Normal and reverse phase chromatography are methods of separation based on a molecule's polarity; in normal phase chromatography, a nonpolar mobile phase is employed so that polar, hydrophilic molecules elute last. The opposite is true for reverse phase chromatography - a polar, aqueous mobile phase is used and any nonpolar molecules tend to adsorb to the hydrophobic beads, causing them to elute out last. Thin layer chromatography is not a good method of purifying substances, rather, it is a better indicator of reaction progress via elucidation of the retardation factor, .

In reverse phase chromatography, the more hydrophobic molecules will be eluted last (the more hydrophilic molecules will be eluted first). This is due to the mobile phase being polar, and thus the nonpolar/hydrophobic molecules adsorbing to the stationary phase. The opposite is true in normal phase chromatography - this technique employs a nonpolar mobile phase and a polar stationary phase. The polar stationary phase will attract polar molecules, and thus the nonpolar molecules will be eluted first along with the nonpolar/hydrophobic mobile phase.

Size exclusion chromatography is a good technique for separating proteins based on size due to tiny pores in the beads in the column (the smaller proteins will elute out last). Cation exchange chromatography is a good technique for separating proteins based on charge due to negatively charged beads in the column (the positively charged molecules will elute out last). Normal and reverse phase chromatography are methods of separation based on a molecule's polarity; in normal phase chromatography, a nonpolar mobile phase is employed so that polar, hydrophilic molecules elute last. The opposite is true for reverse phase chromatography - a polar, aqueous mobile phase is used and any nonpolar molecules tend to adsorb to the hydrophobic beads, causing them to elute out last. Thin layer chromatography is not a good method of purifying substances, rather, it is a better indicator of reaction progress via elucidation of the retardation factor, .

In reverse phase chromatography, the more hydrophobic molecules will be eluted last (the more hydrophilic molecules will be eluted first). This is due to the mobile phase being polar, and thus the nonpolar/hydrophobic molecules adsorbing to the stationary phase. The opposite is true in normal phase chromatography - this technique employs a nonpolar mobile phase and a polar stationary phase. The polar stationary phase will attract polar molecules, and thus the nonpolar molecules will be eluted first along with the nonpolar/hydrophobic mobile phase.

Graduated cylinders are often used for measuring volumetric quantities. As these have several markings, they are considered accurate. Volumetric flasks are also used to accurately measure liquid volume quantities. Lastly, burettes are used to accurately measure volumes of liquid during titrations.

In contrast, beakers are not typically used to measure accurate quantities of liquid; though they have markings on them, these are approximate measurements. Graduated cylinders are often used to accurately measure out a liquid, and beakers to then hold the liquid.

A first-order reaction can be expressed in different ways. One way is the following:

where:

= concentration of reactant at a given time,

= initial concentration of reactant at time

= rate constant of the reaction

= amount of time that has passed since the start of the reaction

By taking the natural logarithm of both sides, we can obtain an alternative form of the equation, expressed as:

This second equation is useful for graphing, because it fits the general equation of . In this case, represents the -axis, represents the -axis, represents the -intercept, and represents the slope. Thus, the graph in the question stem is indeed indicative of a first-order reaction.

In the case of a zeroth-order reaction, the equation is:

Therefore, for a zeroth-order reaction, a straight line with a negative slope will only result from a graph of the concentration of a reactant versus time.

And lastly, in the case of a second-order reaction, the equation is:

Hence, a graph of the inverse concentration of a reactant versus time will yield a straight line with a positive slope, and this is indicative of a second-order reaction.

The critical point for water is at 218atm and 374 degrees Celcius, but on this graph it can be found at the end of the line between the gas and liquid portions of the water phase graph (you can see it end with a dot). This means we need to increase our pressure and decrease our temperature in order to reach the critical point from our initial conditions.

The critical point for water is at 218atm and 374 degrees Celcius, but on this graph it can be found at the end of the line between the gas and liquid portions of the water phase graph (you can see it end with a dot). This means we need to increase our pressure and decrease our temperature in order to reach the critical point from our initial conditions.

A first-order reaction can be expressed in different ways. One way is the following:

where:

= concentration of reactant at a given time,

= initial concentration of reactant at time

= rate constant of the reaction

= amount of time that has passed since the start of the reaction

By taking the natural logarithm of both sides, we can obtain an alternative form of the equation, expressed as:

This second equation is useful for graphing, because it fits the general equation of . In this case, represents the -axis, represents the -axis, represents the -intercept, and represents the slope. Thus, the graph in the question stem is indeed indicative of a first-order reaction.

In the case of a zeroth-order reaction, the equation is:

Therefore, for a zeroth-order reaction, a straight line with a negative slope will only result from a graph of the concentration of a reactant versus time.

And lastly, in the case of a second-order reaction, the equation is:

Hence, a graph of the inverse concentration of a reactant versus time will yield a straight line with a positive slope, and this is indicative of a second-order reaction.

The critical point for water is at 218atm and 374 degrees Celcius, but on this graph it can be found at the end of the line between the gas and liquid portions of the water phase graph (you can see it end with a dot). This means we need to increase our pressure and decrease our temperature in order to reach the critical point from our initial conditions.