i know that tin and hcl are enough, but i would like to know how they can mixed ,and in which proportion, to get a specific concentration.

i found an example where are used:

12gr pure tin

50cl hydrochloric acid 35% solution

the author claims that in this way the final concentration will be 2M

someone can explain me why the final concentration will be 2M with this proportion of tin and hcl?

thank you!