Question

what does NaBr + Ca(OH)2 -> CaBr2 + NaOH create? is it a physical or chemical or physical? for an example for what does it create: like rust

Answer 1

Answer: The given reaction is a chemical change and equation for rust is given below.

Explanation:

A chemical change is defined as the change where a change in the chemical composition takes place and results in the formation of a new substance. These reactions are usually an irreversible reaction.

A physical change is defined as the change in the shape and size of a substance. No change in the composition of a substance takes place as no new substance is formed. These reactions are usually reversible reaction.

For the given reaction:

$2NaBr+Ca(OH)_2\rightarrow CaBr_2+2NaOH$

The given reaction is a chemical change because new substances are being formed. This is an example of double displacement reaction because exchange of ions is taking place.

The formation of rust is also a chemical change because a reddish-brown coating on iron metal is being formed which is the rust. The equation for the following chemical change is:

$4Fe(s)+3O_2(g)\rightarrow 2Fe_2O_3(s)$