A 8.85 g sample of hydrate of sodium carbonate, Na2CO3 ∙ XH2O was heated carefully until no more mass was lost from the sample. After heating, the final weight of the material was 7.55 g. How many moles of Na2CO3 remained after heating?

Afamily is one another name for a group on the table of elements.

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?