How many moles are in 1.25 grams of MgCl2?

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

When balancing a chemical equation:

Calculate the concentration of all species in a 0.165 m solution of h2co3.