2. Which reaction is not a correctly balanced single replacement reaction? 2Al+3CuCl_(2)arrow 2AlCl_(3)+3Cu 2C_(2)H_(6)+7O_(2)-4CO_(2)+6H_(2)O 3Ca+2FeBr_(3)+3CaBr_(7)+2Fe 2LiCl+F_(2)arrow 2LiF+Cl_(2)

The reaction that is not correctly balanced is:<br /><br />$3Ca+2FeBr_{3}\rightarrow 3CaBr_{7}+2Fe$<br /><br />In this reaction, the number of bromine atoms on the left side of the equation is 6 (from 2FeBr3), but on the right side, it is 7 (from 3CaBr7). Therefore, the reaction is not balanced correctly.