How many grams of cac2 would make 23.6g c2h2 ?

CaC2 + 2 H2O = C2H2 + Ca(OH)2

moles CaC2 = 485 g/64.1 g/mol=7.57  

moles H2O = 2 x 7.57 =15.1  

mass H2O = 15.1 mol x 18.02 g/mol=272.8 g  

moles C2H2 = 23.6 /26.038 g/mol=0.906  

moles CaC2 = 0.906  

mass CaC2 = 0.906 x 64.1 =58.1 g  

moles Ca(OH)2 = 55.3 / 74.092 =0.760  

moles H2O = 2 x 0.760 =1.52  

mass water = 18.02 x 1.52 =27.4 g

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.