Replacement Chemical ReactionsChristian Henderson

Mrs. Jemmott

Science Fair

A Single Replacement Reaction is a type of oxidation-reduction chemical reaction where one element takes the place of another in a compound. Usually the product and reactant compounds are in the aqueous solution. The element taking the place of the other is normally more reactive in the activity series, and the element being replaced will be pulled out of the compound alone.

This Table is a list of the reactive elements in order from highest reactivity value to the lowest. Every element that is above another is more reactive the all the elements below it. As well as the element lower than an element on this table will be replaced by any element above.

A Cation is a positively charged ion or metal. In an oxidation-reduction reaction the cation is oxidized and will replace an element that is reduced.

If the reactant element is less reactive than this will result in NO REACTION

An anion is a negatively charged ion or a nonmetal. In an oxidation-reduction reaction the anion is reduced and will replace an element that is oxidized.

If the reactant element is less reactive than this will result in NO REACTION

In an experiment that was conducted, pennies (that were produced after 1982) that were made with a Zinc core and copper shell were placed in HCl (Muriatic Acid). The replacement equation was:

Zn + HCl ZnCl2 + H2

The Zinc from inside the copper shell was higher than Hydrogen on the Activity Series as a result Hydrogen was release in gas form, and Zinc replaced Hydrogen in the solution. The hollow copper shell was the only thing left of the penny. Hydrogen gas was released into the atmosphere.

In galvanized steel, when the steels would begin to rust. The Zinc coating will undergo a single replacement reaction making the rust turn back into metal Iron, transforming back to steel.

Polishing Silver Jewelry, after a while silver will tarnish. The solution you use will replace the tarnish caused by the reaction with the jewelry and oxygen.

A chemical reaction between two compounds where the positive ion of one compound is exchanged with the positive ion of another compound.

The very common experiment is the reaction between Vinegar and Baking Soda. Many young chemists are unaware that this is actually TWO reactions occurring. What actually happens is this: acetic acid (within the vinegar) reacts with sodium bicarbonate (within the baking soda) to form carbonic acid. Carbonic acid is unstable, decomposes into carbon dioxide and water.

Bubbles form from the decomposition of the carbon dioxide escaping the solution that is left. Carbon dioxide is much heavier than air so, it overflows and escapes the container; being pulled by gravity. Left is a dilute solution of sodium acetate within water.

As well as carbon dioxide being released into the atmosphere.

CH3COOH + NaHCO3 ---> CH3COONa + H2CO3

H2CO3 ---> H2O + CO2

Conclusion

Single Replacement Reactions are reactions in which a more reactive element will replace a not as reactive element in a compound.

Double Replacement Reactions are when two elements will “swap places” in two different compounds.