If a sample contains 84.0 % of the R enantiomer and 16.0 % of the S enantiomer, what is the enantiomeric excess of the mixture

enantiomeric excess = 68%

Explanation:

Enantiomeric excess is a value used to determine the purity of chiral molecules. It is possible to determine enantiomeric excess (ee) using:

ee = R - S / R + S * 100

Where R is the mass (In this case percentage) of the R enantiomer and S of the S enantiomer.

Replacing with values of the problem:

ee = 84% - 16% / 84% + 16% * 100

1- Option (2)

2- Option (3)

3- Option (1)

Explanation:

The rock cycle refers to the cyclic process that leads to the formation of three different types of rocks namely the igneous, sedimentary and the metamorphic rocks, and also their alteration from one rock type to another under certain factors and conditions.

In order to form another type of rocks that are to be deposited in some other environment, the source rock must undergo the process of weathering and erosion. Weathering leads to the breakdown of rocks and erosion leads to the transportation of the broken fragments and sediments. This new sediments after deposition and lithification will give rise to the formation of sedimentary rocks such as Sandstone and Limestone.

The rocks that are formed under extremely high pressure and temperature condition are usually known as metamorphic rocks. These are directly obtained from the previously existed sedimentary or igneous or other metamorphic rocks. So they are also known as secondary rocks. For example, Quartzite, Schist, and Gneiss.

The rocks that are directly derived from the cooling and solidification of magma are known as igneous rocks. When these rocks are crystallized below the earth's surface then they are called intrusive igneous rocks, and when they crystallized on the earth's surface then they are called extrusive igneous rocks. For example, Granite and Basalt.

Thus, the correct answers are mentioned above.