Consider these statements. (1) HF can be made by heating CaF2 with concentrated H2SO4. (2) Pure HBr can be made by heating NaBr with concentrated H2SO4. (3) HI can be made by heating KI with phosphoric acid. (4) HCl can be made by heating NaCl with concentrated H2SO4. The number of correct statements is

JEE Advanced levelSingle correct optionDifficulty 3 of 3ph038

Consider these statements. (1) $HF$ can be made by heating $CaF X_{2}$ with concentrated $H X_{2} SO X_{4}$ . (2) Pure $HBr$ can be made by heating $NaBr$ with concentrated $H X_{2} SO X_{4}$ . (3) $HI$ can be made by heating $KI$ with phosphoric acid. (4) $HCl$ can be made by heating $NaCl$ with concentrated $H X_{2} SO X_{4}$ . The number of correct statements is

Statements 1, 3 and 4 are correct, since in each case a non-oxidising route frees the HX gas. Statement 2 is wrong:

HBr

is oxidised by hot concentrated

H X_{2} SO X_{4}

Br X_{2}

(with

SO X_{2}

), so

H X_{3} PO X_{4}

is used. Hence 3 are correct.