The three substances that cause a double displacement reaction to occur are:
(i) Ionized compounds. These are usually water.
(ii) A gas that bubbles out a solution.
(iii) A precipitate.
In double displacement reaction is where two new compounds are formed when two parts of two compounds switch places. For example; when sodium chloride combines with silver nitrate, the two new compounds formed are Sodium nitrate and silver chloride reason being sodium and silver switched places.
As a rule of thumb, a person will eliminate one average drink or . 5 oz (15 ml) of alcohol per hour. Several factors influence this rate. The rate of elimination tends to be higher when the blood alcohol concentration in the body is very high.