What factors determine whether a volcanic eruption will be violent or relatively quiet?

Answer: Based off of the type of chemical reaction goes on in the lava before it explodes

Explanation:

There are two main factors that influence how a volcano will erupt are viscosity and gas content. Both are related to the composition of the magma. Hawaiian volcanoes tend to erupt basalt, which is low in viscosity and low in gas content (about 0.5 weight percent).

The volcanoes are an important feature often found on the surface of the earth. They are directly associated with the convergent and divergent type of plate boundary.

These eruptions of the volcano takes place either violently or quietly. This violent or silent explosive nature is determined by the following factors, such as-

Amount of silica content in the magma - If silica content is more, then the viscosity of magma is high and it flows sluggishly and is very violent in nature ejecting a lot of pyroclastic materials. Low viscosity magma flows easily and rapidly. Amount of dissolved gas present in magma - When there is more amount of dissolved gas, then it is more violent releasing a large number of gases. The temperature of magma - High-temperature magma are more violent than the low-temperature magma.

These are the main factors that describe if the eruption is explosive or not.