CHEMISTRY · Single correct · AP · Chemistry · Chemical Reactions · Chemical Reactions
Problem
A self-heating field ration (meal, ready-to-eat) contains a sealed pouch of powdered Mg–Fe alloy beneath the food tray. When a soldier adds water and seals the outer bag, three events are observed:
1. A rapid temperature rise inside the bag.
2. Formation of bubbling gas around the alloy pouch.
3. Condensation of water droplets on the inner surface of the plastic bag.
Which option correctly classifies each event as evidence of a physical change (P) or evidence of a chemical change (C)?
(a) 1(P)2(P)3(C)
(b) 1(C)2(C)3(P)
(c) 1(P)2(C)3(C)
(d) 1(C)2(P)3(P)