A substance made of two or more elements that have been chemically combined is a(n) ______.

Chemistry

2 answers:

RideAnS [48]3 years ago

5 0

Compound (for example: H2O)

Anvisha [2.4K]3 years ago

3 0

Answer: Compound

Explanation:

Element is a pure substance which is composed of atoms of similar elements. Example: $Fe$

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass. Example: $CaCO_3$

Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material. Example: Sugar solution

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Ibuprofen is a drug used to manage mild pain, fever, and inflammation. It is a chiral drug, and only the S enantiomer, whose spe

madam [21]

Answer:

Specific Rotation = 105º

S% in mixture = 92%

Explanation:

Specific rotation in organic compounds varies linearly, then the enantiomeric excess can be express as:

$e.e. = \frac{\alpha }{\alpha pure}$

Where alpha is the specific rotation of the mixture and alpha pure is the specific rotation of the excess enantiomer.

Then, knowing that the S enantiomer is in excess you can calculate the specific rotation of that mixture:

$84=\frac{\alpha }{125.0}*100$

$\alpha =105 Degrees$

For calculating the percentage of S you should remember that the enantiometric excess is the percentage of excess of a certain enantiomer, for example in this case:

$84 = S-R$