Hydrofluoric acid, hf(aq), cannot be stored in glass bottles because compounds called silicates in the glass are attacked by the hf(aq). sodium silicate (na2sio3), for example, reacts as shown below. na2sio3(s) + 8 hf(aq) h2sif6(aq) + 2 naf(aq) + 3 h2o(l) (a) how many moles of hf are needed to react with 0.340 mol of na2sio3?