Question

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

Answer 1

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