Astudent heats 2.796g of zinc powder with 2.414g of sulphur. he reported that he obtained 4.169g of zinc sulfide and recover 1.041g of unreacted sulfur.
show by calculation whether or not his results obey the law of conversation of mass

The mass of reactants and products are equal hence the reaction obeys law of conservation of mass

Explanation:

The law of mass conservation states that for a closed system to all transfer of mass, the mass of system must remain constant over time. This means for a chemical reaction, the mass of reactants must equal the mass of products.

if 2.796g of Zn reacts with 2.414g of sulphur to produce 4.169g of ZnS ad 1.041g of unreacted sulphur, then it means that accorfing to the law of mass conservation, the mass of reactants (zinc and sulphur), must be equal to mass of products (zinc sulfide and unreacted sulphur)

Mass of reactants = 2.796g + 2.414g =5.21g

Mass of products = 4.169g + 1.041g=5.21g

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

it takes on an electronical energy