Chemistry Past Questions and Answers

The atomic number of an element whose cation, X<sup style='font-size: smaller;'>2+</sup>, has the ground state electronic configuration 1s<sup style='font-size: smaller;'>2</sup>2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup>3s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> is?

When marble is heated to about 1473 K, another white solid is obtained which reacts vigorously with water to give an alkaline solution. The solution contains?

Addition of dilute hydrochloride acid to an aqueous solution of a crystalline salt yield a yellow precipitate and a gas which turned dichromate paper green. The crystalline salt was probably?

The process involved in the conversion of an oil into margarine is known as?

An aqueous solution of an inorganic salt gave white precipitate (i) soluble in excess aqueous NaOH (ii) insoluble in excess aqueous NH<sub style='font-size: smaller;'>3</sub> (iii) with dilute HCl. The cation present in the inorganic salt is?