Zn and HCl are the reactant in the equation above. zinc react with 2 moles of Hcl to form zinc chloride and a hydrogen molecule. The one equation means that the reaction proceed to the forward side only therefore no reverse of the reaction.
Answer:
ACTIVITY 1
Sample 1 has a stronger taste of lemon, and is more sour.
Sample 2 has a sweeter taste, my guess is because there's more sugar:lemon juice ratio.
Answer : The correct option is, (2) 8 mole of hydrogen will react with 1 mole of sulfur.
Explanation :
The balanced chemical equation is,

By the stoichiometry we conclude that, 8 moles of hydrogen react with 1 mole of sulfur to give 8 moles of hydrogen sulfide.
Hence, the correct options is, (2) 8 mole of hydrogen will react with 1 mole of sulfur.
First look for the atomic number and that is the electron for barium