What is the mole fraction of hydrogen chloride in hydrochloric acid which contains 36% HCl by mass?
A. 0.11

B. 0.22 

C. 0.33

D. 0.44

According to the following reaction, how many moles of hydrochloric acid are necessary to form 0.461 moles iron(II) chloride? iron (s) + hydrochloric acid (aq) iron(II) chloride (aq) + hydrogen(g)

_____ moles hydrochloric acid

A 55 g sample of impure zinc reacts with exactly 129 cm3 hydrochloric acid which has a density of 1 .18 g/cm3 and contains 35.0% HCl by mass. What is the percent metallic zinc in the sample? assume the impurity is inert to HCl. Please show all work and the answer.