Question

What does an arrow pointing downward in a chemical reaction indicate

Answer 1

There are several rules for writing a particular chemical equation . We have to state the state of matter in which the respective reactants and products in the chemical reaction are present .

If any substance is present in the solid state , then it is denoted by giving an small s in bracket near the substance present in the solid state . If any substance is present in the liquid state then it is denoted by giving a small l in bracket near the substance present in the liquid state and similarly , if some substance is dissolved in water then an aq is given in bracket near the substance to denote aqueous solution . And if some substance is present in the gaseous state , then a small g is given in bracket near the substance present in the gaseous state .

Now if in a chemical reaction , a gas has evolved , then that is denoted by means of giving an arrow directed in the upward direction near the substance which has evolved in the reaction . For example :

CaCO3(s) → CaO(s) + CO2↑

On the other hand if some substance has precipitated in a reaction than it is denoted by giving a downward arrow near the substance which has precipitated . For Example :

NaCl(aq) + AgNO3(aq) → NaNO3(aq) + AgCl↓

Answer 2

It indicates that the product which is formed is getting settled down..
hope this will help u.. :-)