Nail VS Soy-Sauce

Can soy sauce dissolve a nail?

Safe­ty pre­cau­tions

Per­form this ex­per­i­ment only un­der adult su­per­vi­sion.

Equip­ment

  • 2 nails;
  • wax can­dle;
  • brush;
  • 2 croc­o­dile clip wires;
  • bat­tery hold­er with 4 AAA bat­ter­ies;
  • glass;
  • soy sauce.

Step-by-step in­struc­tions

Ap­ply some melt­ed can­dle wax to the first nail. Use a knife to make a 2 mm gap in the wax coat­ing. Put two nails in a glass and im­merse them in soy sauce. Con­nect to a bat­tery hold­er with 4 AAA bat­ter­ies. Con­nect the red croc­o­dile clip (pos­i­tive) to the wax-coat­ed nail, and the black croc­o­dile clip (neg­a­tive) to the bare nail. Leave for 30-40 min­utes. Re­move the wax-coat­ed nail from the sauce and wipe it with a pa­per tow­el. The nail has dis­solved at the gap in the wax! You can break it eas­i­ly us­ing just your hands.

Pro­cess­ de­scrip­tion

Soy sauce con­tains a con­sid­er­able amount of salts, main­ly sodi­um chlo­ride. Thus, it is able to con­duct an elec­tric cur­rent. When the nails in the so­lu­tion are con­nect­ed to a bat­tery, the elec­tric cir­cuit clos­es. On the pos­i­tive elec­trode - the waxed nail, the un­pro­tect­ed met­al dis­solves:

Fe⁰ - 2e = Fe²⁺

Fe⁰ - 3e = Fe³⁺

Аnd on the neg­a­tive elec­trode, gaseous hy­dro­gen is re­leased:

2H₂O + 2e = H₂↑ + 2OH-

But an­oth­er chem­i­cal process will take place in the so­lu­tion it­self: the re­sult­ing re­ac­tion prod­ucts will re­act with each oth­er and pre­cip­i­tate in the form of iron(II) and iron(III) com­pounds. A sim­i­lar ex­per­i­ment is in­clud­ed in the “Cor­ro­sion” kit from the MEL Chem­istry sub­scrip­tion.