2C+2H2=C2H4 square Au+Au __ square 2Ca+O2=2CaO __ square 4Al+3O2=2Al2O3 __ square 2H_(2)+O_(2)=2H2O __ square Cl+Cl=Cl2 __ square square H_(2)+Cl2=2HCl2 __ square 2Na+Cl2=2NaCl __ square 3H2+2N=2NH3 __ square

Let's go through each chemical equation and balance them correctly:<br /><br />1. $2C + 2H_2 = C_2H_4$<br /> - This equation is not balanced correctly. The correct balanced equation should be:<br /> $2C + 2H_2 = C_2H_4$<br /> - $\square$<br /><br />2. $Au + Au$<br /> - This equation is incomplete. The correct balanced equation should be:<br /> $2Au = 2Au$<br /> - $\square$<br /><br />3. $2Ca + O_2 = 2CaO$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />4. $4Al + 3O_2 = 2Al_2O_3$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />5. $2H_2 + O_2 = 2H_2O$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />6. $Cl + Cl = Cl_2$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />7. $H_2 + Cl_2 = 2HCl$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />8. $2Na + Cl_2 = 2NaCl$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />9. $3H_2 + 2N_2 = 2NH_3$<br /> - This equation is balanced correctly.<br /> - $\square$<br /><br />So, the balanced equations are:<br /><br />1. $2C + 2H_2 = C_2H_4$<br />2. $2Au = 2Au$<br />3. $2Ca + O_2 = 2CaO$<br />4. $4Al + 3O_2 = 2Al_2O_3$<br />5. $2H_2 + O_2 = 2H_2O$<br />6. $Cl + Cl = Cl_2$<br />7. $H_2 + Cl_2 = 2HCl$<br />8. $2Na + Cl_2 = 2NaCl$<br />9. $3H_2 + 2N_2 = 2NH_3$