How many moles of aluminum chloride can be made from 60 mol hydrochloric acid and excess aluminum

Question

The equation is: 2Al+6HCl=2AlCl3+3H2

Answer 1

One important piece of information that we can get from chemical equations is the molar ratio between elements in a reaction. The coefficients actually tell us how the number of moles of one molecule can translate to the number of moles of another molecule. In this case, we know that 6 moles of HCl can yield 2 moles of AlCl₃ based on the coefficients (when there is an excess amount of aluminum). Therefore the ratio of HCl:AlCl₃ is 6:2. Using this same logic, if we have 60 moles of HCl (10x6 moles), then we must be able to form 20 moles of AlCl₃ (10x2 moles).