How to make fuel from fertilizer and a food additive

A simple way to make a rocket fuel

Safe­ty pre­cau­tions

Ob­serve nec­es­sary safe­ty pre­cau­tions when work­ing with heat­ing el­e­ments. Wear pro­tec­tive gloves, eye­wear, and a mask. Con­duct this ex­per­i­ment in a well-ven­ti­lat­ed area.

Reagents and equip­ment

  • 5 g of cal­ci­um ni­trate tetrahy­drate;
  • 5 g of potas­si­um hex­a­cyano­fer­rate(II) tri­hy­drate;
  • an alu­minum con­tain­er;
  • a gas burn­er;
  • a sol­id fuel stove;
  • a beaker;
  • a wood­en stick.

Step-by-step in­struc­tions

Mix 5 g of cal­ci­um ni­trate tetrahy­drate and 5 g of potas­si­um hex­a­cyano­fer­rate(II) tri­hy­drate in the beaker. Pour this mix­ture into the alu­minum con­tain­er and place it on the stove. Heat, stir­ring with the wood­en stick, un­til all the mois­ture evap­o­rates. Once the mix­ture cools down, use a blow­torch to ig­nite it. Ob­serve the re­sult­ing pil­lar of fire, which re­sem­bles the flame of a rock­et!

Process de­scrip­tion

Cal­ci­um ni­trate is of­ten used in agri­cul­ture as a fer­til­iz­er, and potas­si­um hex­a­cyano­fer­rate(II) is em­ployed as an an­ti­cak­ing ad­di­tive in food pro­cess­ing (in ta­ble salt, for in­stance). When these two salts are heat­ed, they dis­solve in the wa­ter con­tained in their own crys­tals, form­ing a ho­mo­ge­neous mix­ture. Once ig­nit­ed, this mix­ture burns sim­i­lar­ly to rock­et fuel.

Cal­ci­um ni­trate ox­i­dizes potas­si­um hex­a­cyano­fer­rate(II), yield­ing molec­u­lar ni­tro­gen and ox­ides of iron(III), cal­ci­um, potas­si­um, and car­bon(IV).

31Ca(NO₃)₂+10K₄[Fe(CN)₆] = 31­CaO + 5Fe₂O₃+ 20K₂O+ 61N₂ + 60­CO₂