Which of the following oxide(s) is/are soluble in water to form alkalis?
(i) Na2O (ii) SO2 (iii) K2O (iv) NO2
(a) (i) and (iii)
(b) (i) only
(c) (ii) and (iv)
(d) (iii) only
(i) Na2O (ii) SO2 (iii) K2O (iv) NO2
(a) (i) and (iii)
(b) (i) only
(c) (ii) and (iv)
(d) (iii) only