Question

Write the molecular mass of $HgC{{O}_{3}}\,,CaC{{O}_{3}},\,C{{H}_{3}}C{{H}_{2}}OH\,,\,A{{l}_{2}}{{(S{{O}_{4}})}_{2}}$

Answer 1

The molecular mass (m) is the mass of a given molecule measured in daltons (Da or u). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. It is calculated by the sum of the atomic mass of the constituent elements.

Complete step by step answer:
The first compound given is $HgC{{O}_{3}}$
The atomic number of $Hg$ is $200.59u$. The atomic number of $C$ is $12.01u$, atomic number of $O$ is $15.99u$.
We will add up the atomic numbers.
$200.59\,+\,12\,+\,(16\,\times \,3)\,=\,260.59$
The molecular mass of $HgC{{O}_{3}}$ is 260.59u.
The next compound is $CaC{{o}_{3}}$.
The atomic number of $Ca$,$C$, $O$ are $40.078u$, $12.01u$, $15.99u$.
The molecular mass of $CaC{{o}_{3}}$ is $100.08u$.
The next compound given is $C{{H}_{3}}C{{H}_{2}}OH$.
The atomic number of $C$ , $H$, $O$ are $12.01u$, $1.00u$, $15.99u$.
The molecular mass of is $C{{H}_{3}}C{{H}_{2}}OH$ $46.07u$.
The next compound is $A{{l}_{2}}S{{O}_{4}}$.
The atomic mass of aluminum is $26.98u$. The atomic mass of S is $32.06u$. The atomic mass of $O$ is $15.99u$.
The molecular mass of $A{{l}_{2}}S{{O}_{4}}$ is $3425.15u$.

Additional information: Aluminum sulfate is a chemical compound with the formula $A{{l}_{2}}S{{O}_{4}}$. It dissolves in water, hence water soluble and is mainly used as a coagulating agent (promoting particle collision by neutralizing charge) in the purification of drinking water and wastewater treatment plants, and also in paper manufacturing.

Note:
The molecular mass of small to medium size molecules, measured by mass spectrometry, are often wont to determine the composition of elements within the molecule. The molecular masses of macromolecules, like proteins, also can be determined by mass spectrometry; however, methods supported viscosity and light-scattering also are wont to determine molecular mass when crystallographic or mass spectrometric data are not available.