Answer:
D.) 2.5 moles
Step-by-step explanation:
To find the moles of H₂, you need to multiply the given value by the mole-to-mole ratio. This ratio consists of the coefficients in front of the relevant molecules. It is important to arrange the ratio in a way that allows for the cancellation of units.
1 Mg + 2 HCl -----> MgCl₂ + 1 H₂
^ ^
2.5 moles Mg 1 moles H₂
----------------------- x --------------------- = 2.5 moles H₂
1 mole Mg