Which of the statement given below are correct ? (i) Pure dihydrogen 99.5 % is obtained by heating hydrocarbons at 1270 K temperature using Fe catalyst. (ii) In acidic medium H_2O_2decolourises potassium permanganate solution. (iii) Ca^(2+) and Mg^(2+) ions can be precipitated by calgon to soften the hard water (iv) The strength of 15 volume H_2O_2 at STP is 45.54 gram.

Which of the statement given below are correct ? (i) Pure dihydrogen

1.	Which of the statement given below are correct ? (i) Pure dihydrogen 99.5 % is obtained by heating hydrocarbons at 1270 K temperature using Fe catalyst. (ii) In acidic medium H_2O_2decolourises potassium permanganate solution. (iii) Ca^(2+) and Mg^(2+) ions can be precipitated by calgon to soften the hard water (iv) The strength of 15 volume H_2O_2 at STP is 45.54 gram.
Answer» (i),(II) (ii),(IV) (ii),(III),(iv) (i),(iii),(iv) ANSWER :C