Which of the following reactions occurs most rapidly at room temperature?

a.2agno3(aq) + na2cro4(aq) → ag2cro4(s) + 2nano3(aq)

b. cao(s) + 3c(s) → cac2(s) + co(g)

c. sno2(s) + 2co(g) → sn(s) + 2co2(g)

d.2fe(s) + o2(g) → 2feo(s)

The correct option is A.

Looking at the options given above, you will notice that the physical states of the chemical compounds were given in the chemical equations. The reaction in option A is the one that will occur most rapidly because the two reactants involved in the reaction are both in liquid state. Reaction of compounds that are in solid state is comparatively slower because of reduced surface area.

the only liquid elements at standard temperature and pressure are bromine (br) and mercury (hg). although, elements caesium (cs), rubidium (rb), francium (fr) and gallium (ga) become liquid at or just above room temperature.

explanation:

i do not get it   at all