(Solved): 4. Hydrofluoric acid (HF(ai) ) is not stored in glass containers ( SiO2(0)) because it reacts ...

4. Hydrofluoric acid $$\left({\mathrm{HF}}_{(\mathrm{ai}}\right)$$ ) is not stored in glass containers ( $${\mathrm{SiO}}_{2(0)})$$ because it reacts with glass. The products of the reaction are $${\mathrm{SiF}}_{4(\mathrm{o})}$$ and water. Calculate the mass of hydrofluoric acid that is needed to react completely with $$15.0\mathrm{g}$$ of glass. a. $$5.00\mathrm{g}$$ b. $$20.0\mathrm{g}$$ c. $$79.9\mathrm{g}$$ d. $$89.5\mathrm{g}$$ 5. The mass of $${\mathrm{Al}}_2{\mathrm{S}}_3(0)$$ that would form when $$50.0\mathrm{ml}$$ of $$0.450\mathrm{mol}/\mathrm{L}{\left({\mathrm{NH}}_4\right)}_2{\mathrm{S}}_{(+0)}$$ reacts with excess $$\mathrm{Al}{\left({\mathrm{NO}}_3\right)}_{\text{sea }})$$ is a. $$0.375\mathrm{g}$$ b. $$0.532\mathrm{g}$$ c. $$1.13\mathrm{g}$$ d. $$3.38\mathrm{g}$$ 6. What volume of $$0.350\mathrm{mol}/\mathrm{L}$$ aqueous calcium hydroxide is needed to neutralize $$275\mathrm{ml}$$ of $$0.450\mathrm{mol}/\mathrm{L}$$ hydrochloric acid? a. $$44.2\mathrm{mL}$$ b. $$88.4\mathrm{ml}$$ c. $$177\mathrm{mL}$$ d. $$354\mathrm{mL}$$