Question: Why does concrete get hot when it is curing? Answer: Simply put, water plus aggregates (gravel, sand, stone), plus cement (such as Portland cement) start a chain of chemical reactions called ...

The reaction of the potassium with water is similar to the reaction of sodium in water ... but does not get nearly as hot as either the sodium or potassium. Also, the calcium hydroxide produced forms ...

The best reaction for use in our hand warmers was the 'slaking' of lime. It generated enough heat for our purposes, and involved chemicals (water, calcium oxide and calcium hydroxide) that are ...