Which of the following reactions would occur at the anode in a voltaic cell? Cd2+ (aq) + Zn (s) --> Zn2+ (aq) + Cd (s)
K+ (aq) + e- --> K (s)
Cu2+ (aq) + 2e- --> Cu (s)
Ca (s) --> Ca2+ + 2e-

the right answer is the last one.

Explanation:

I I know because I've done this before.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g