The answer is "A. a pure substance can be separated by chemical means, while a mixture can be separated by physical means". A pure substance only has one type of substance, whereas a mixture has more than one. A pure substance therefore, can only be separated chemically, because it is not two things mixed together, whereas a mixture can be separated physically because there are multiple substances.
Answer:
Molecule is the general term used to describe any atoms that are connected by chemical bonds. Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements. All compounds are molecules, but not all molecules are compounds.
Explanation:
Explanation:
the answer will be 98.4 kJ
Answer:
13.92 %
Explanation:
Mass of 
= 12.5221 g
Molar mass of = 233.43 g/mol
The formula for the calculation of moles is shown below:
Thus,
Moles of = 0.0536 moles
According to the given reaction,
1 mole of is formed from 1 mole of 
Thus,
0.0536 moles of is formed from 0.0536 moles of
Moles of = 0.0536 moles
Moles of sulfur in 1 mole = 1 mole
Moles of sulfur in 0.0536 mole = 0.0536 mole
Molar mass of sulfur = 32.065 g/mol
Mass = Moles * Molar mass = 0.0536 * 32.065 g = 1.7187 g
Mass of ore = 12.3430 g
Mass % = 
= 
= 13.92 %
