A first order reaction: A(g) -> 3B(g) is performed in a cylinder piston arrangement, at constant temperature & pressure, starting with 2 moles A(g) & 1 mole of B(g) . After 90 minutes from the start of the reaction, the molar ratio of A(g) to B(g) becomes 1:25. The initial volume of system was 12 Litres. How many of the following statement(s) is/are correct (with respect to this reaction)?
1. (1/2) of the reaction is 30 min.
II. Volume of the system at t = 90 min is 26 L.
III. At t 90 min., [A]=( 1 / (48) ) M
IV. At t = 90 min., [B] = (25/104) M
A 0
B 1
C 2
D 3​