A 6.72 g sample of zinc was placed in 100.0 mL of 1.50 mol/L hydrochloric acid. After all reaction stops, how much zinc should remain?

1.82g of Zn remain

Explanation:

Zinc, Zn, reacts with hydrochloric acid, HCl, as follows:

Zn + 2HCl → ZnCl2 + H2

Where 1 mole of Zn reacts with 2 moles of HCl

To solve this question we must find the moles of each reactant. With the moles of HCl we can find the moles of zinc needed for a complete reaction and the mass of zinc that remains:

Moles Zn -Molar mass: 65.32g/mol-

6.72g * (1mol / 65.38g) = 0.1028 moles Zn

Moles HCl:

100.0mL = 0.1000L * (1.50mol / L) = 0.150moles HCl

The moles of Zn that react with 0.150 moles HCl are:

0.150 mol HCl * (1mol Zn / 2mol HCl) = 0.075 moles of Zn are required

The moles that remain are:

0.1028 moles Zn - 0.075 moles of Zn = 0.0278 moles Zn

The mass is:

0.0278 moles Zn * (65.38g / mol) =

"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's filtration, but this is an assumption so my apologies if i got this