Mg + 2HCl ----> MgCl2 + H2 5. If I have 45.1 moles of magnesium and 39.8 moles of HCl, how many moles of MgCl2 are formed?

Question

could you please help me answering this question. It is foe eleventh grade.

 

Thank you.

Answer 1

Same here. use the mole ratio: Mg : HCl : MgCl₂ : H₂ = 1:2:1:2

 

For 45.1 moles of Mg you would need 90.2 moles of HCl. You only have 39.8 moles of HCl. HCl is the limiting agent in this reaction. 

39.8 moles of HCl will react with 19.9 (=39.8/2) moles of Mg and will result in 19.9 moles of MgCl₂.

Always apply the mole ratio of the balanced reaction equation.

 

good luck