Predict the precipitate when the double replacement reaction occurs:
ca(no3)2(aq) + na2co3(aq) →

The precipitate formed is calcium carbonate.

Explanation:

double replacement reaction is the chemical reaction in which two reactant  exchanges their respective ions to give new substance as a product.

AB+CD→CB+AD

In a given reaction:

When calcium nitrate reacts with sodium carbonate in aqueous they give white colored precipitate of calcium sulfate and aqueous solution of sodium nitrate.

Increasing until terminal velocity is reached

Explanation:

Provided the scream is a constant pitch at the source, Doppler effect will make the pitch increase as the velocity of the source towards the listener increases.