This is a synthesis reaction, where 2 reactants combine to form a single product.
In decomposition, 1 reactant splits into 2 products. In single replacement, one element swaps with another, in the form A + BC = B + AC. In double displacement two elements swap, in the form AB + CD = AD + CB In neutralization (a kind of double displacement), an acid and a base react to form water and a salt.
I could create a slower reaction because the particles might be moving slower due to the cold. if it was warm there will be a faster reaction. similar to the elements movements in solids and liquids.