4. Hydrofluoric acid (HF(ai) ) is not stored in glass containers ( SiO2(0)) because it reacts with glass. The products of the reaction are SiF4(o) and water. Calculate the mass of hydrofluoric acid that is needed to react completely with 15.0g of glass. a. 5.00g b. 20.0g c. 79.9g d. 89.5g 5. The mass of Al2S3(0) that would form when 50.0ml of 0.450mol/L(NH4)2S(+0) reacts with excess Al(NO3)sea) is a. 0.375g b. 0.532g c. 1.13g d. 3.38g 6. What volume of 0.350mol/L aqueous calcium hydroxide is needed to neutralize 275ml of 0.450mol/L hydrochloric acid? a. 44.2mL b. 88.4ml c. 177mL d. 354mL