(A) lon exchago chromatography  (X)
(B) Thin layer Chromatography (X)
(C) Paper Chromatography  ()
(D) None of these (X)

Answers: The most common and simple technique of chromatography is Paper Chromatography.

(A)  tin ()
(B)  oxygen (X)
(C)  carbon (X)
(D) chlorine (X)

Answers:  tin

(A)  0.27 mole (X)
(B)  0.18 mole ()
(C)  0.24 mole (X)
(D) 0.09 mole (X)

Answers: moles of each aluminium and oxygen react with each other to produce aluminium oxide. The amount of product formed is 0.18 mole.

(A) molecular formula ()
(B) formula unit (X)
(C) empirical formula (X)
(D) formula mass (X)

Answers:  molecular formula

(A) 280 (X)
(B) 154 ()
(C)  300 (X)
(D) 54 (X)

Answers: The number of isotopes of elements with even mass number and even atomic number are 154.

(A)  6.022 x 1023 atms of carbon (X)
(B)  6.022 x 1023 atoms of oxygen (X)
(C)  22-gram electrons (X)
(D)  both B. & C. ()

Answers:  both B. & C.