What is the mass in grams of 1.80 moles of calcium?

You need the atomic masses : 
... 

For 2.50 mol S : 
... 

m = ( 2.50 ) ( 32.07 ) = 80.18 g < 

For 1.80 mole Ca : 
... 

m = ( 1.80 ) ( 40.08 ) = 72.14 g < 

For 0,50 mole C : 
... 

m = (12 )( 0.5 ) = 6.0 g C < 

For the Cu : 
... 

m sub Cu = (nN sub CU ) 

m sub Cu = ( 3.20 ) 63.55 ) = 203.26 g <

Answerthe half-reaction having the greatest tendency to occur at the anode:     i₂(aq) + 2e⁻  ⇄ 2i⁻  ;   e = +0.53 v======oxidation occurs at the anode. we must therefore find the half-reaction with the greatest tendency to oxidize.the given values of e are reduction potentials (the form of the half-reactions are of reduction).the lower the reduction potential, the higher the potential to oxidize. the half-cell with the lowest reduction potential will have the greatest tendency to oxidize at the anode.the half-reaction having the greatest tendency must be    i₂(aq) + 2e⁻  ⇄ 2i⁻    e = +0.53 vbecause its reduction potential is the lowest out of the three.

Ibelieve the answer is d. bleachhope my answer has you : )