Calculate the mass fractions of chemical elements in CaSO4.

| January 31, 2021 | education

To find the mass fraction of each element in a substance, we use the formula:

w = ((n * Ar): M) * 100%; where w is the mass fraction of the element in the substance, n is the number of atoms of the element, Ar is the relative atomic mass of the element (we look at the periodic table), M is the relative molecular weight of the substance (it is made up of Ar of all the elements that make up the substance).

w (Ca) = ((1 * 40g / mol): 136g / mol) * 100% = 29.4%;

w (S) = ((1 * 32g / mol): 136g / mol) * 100% = 23.5%;

w (O) = 100% – (w (Ca) + w (S)) = 100% – (29.4% + 23.5%) = 47.1% (this option for finding the w element is applicable only when it remains to find the w of the last element). w (O) can also be found by the formula, the answer will be the same.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.