During a lab experiment with magnesium and hydrochloric acid, Curious Carl observed bubbles being produced. He identified the gas as being hydrogen. The formula is: Mg + 2HCl → MgCl2 + H2 (g) - What is the mass in grams of two moles of HCl?

A. 18.3 g

B. 36.5 g

C. 73.0 g

D. 82.6 g

From the periodic table:

molecular mass of hydrogen = 1 gram

molecular mass of chlorine = 35.5 grams

Therefore,

mass of one mole of HCl (molar mass) = 1 + 35.5 = 36.5 grams

To get mass of two moles, we will simply multiply the molar mass by 2 as follows:

mass of 2 moles of HCl = 2 x 36.5 = 73 grams

Answer: (C) 73 grams