411. The common oxidation state of lanthanides is_________?
A. +3
B. +2
C. +1
D. +4

412. Which of the following is most soluble on water?
A. BaSO4
B. SrSO4
C. CaSO4
D. MgSO4

413. Which of the following orbitals has maximum penetration effect?
A. S
B. P
C. d
D. f

414. Which of the following phenomenon is considered responsible for Global Warming?
A. Greenhouse effect
B. Fire in coal mines
C. Dry farming
D. Monsoon

415. The number of d-electrons in Fe2+ (Z = 26) is not equal to that of____________?
A. p-electrons in Ne(Z = 10)
B. s-electrons in Mg(Z = 12)
C. d-electrons in Fe(Z = 26)
D. p-electrons in CI(Z = 17)

416. The metallurgical process in which a metal is obtained in a fused state is called__________?
A. smelting
B. roasting
C. calcinations
D. froth floatation

417. The molecules of which gas have highest speed?
A. H2 at -73oC
B. CH4 at 300 K
C. N2 at 1,027oC
D. O2 at 0oC

418. The law which states that the amount of gas dissolved in a liquid is proportional to its partial pressure is___________?
A. Dalton’s law
B. Gay Lussac’s law
C. Henry’s law
D. Raoult’s law

419. The main buffer system of the human blood is____________?
A. H2CO3 – HCO3
B. H2CO3 – CO32-
C. CH3COOH – CH3COO–
D. NH2CONH2 – NH2CONH+

420. The most commonly used bleaching agent is_________?
A. alcohol
B. carbon dioxide
C. chlorine
D. sodium chlorine