Calculate the mass fractions of each element in the following compounds a) MgO b) CO2 h) Al2O3 k) KMnO4.
January 20, 2021 | education
| The mass fraction of an individual element that is part of the compound is calculated as follows:
w% (element) = Mr (element): Mr (substance) * 100%.
Using this formula, we find the mass fractions of elements in the composition of the given substances:
a) MgO:
w% (Mg) = Mr (Mg): Mr (MgO) * 100% = 24: 40 * 100% = 60%,
then oxygen accounts for 100% – 60% = 40%
b) CO2:
w% (O) = (2 * 16): Mr (CO2) * 100% = (2 * 16): 44 * 100% = ~ 72.7%,
then the share of carbon accounts for 100% – 72.7% = 27.3%.
c) Al2O3:
w% (Al) = (2 * 27): 102 * 100% = 53%,
then oxygen accounts for 100% – 53% = 47%.
d) KMnO4:
w% (K) = 39: 158 * 100% = 24.7%
w% (Mn) = 55: 158 * 100% = 34.8%,
then oxygen accounts for 100% – (24.7% + 34.8%) = 100% – 59.5% = 40.5%.
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.