The balanced chemical equation is :

Moles of
,

Now, by given chemical equation , we can see 2 mole of
react with 1 mole of
.
So , 2.27 mole react with :

Mass of oxygen is :

Therefore, mass of oxygen in grams produced is 18.16 g.
Hence, this is the required solution.
Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
= Avogadro's number = 
For the 4.12 g sample
Moles of a substance is given by

Number of molecules is given by

For the 19.37 g sample

Number of molecules is given by


So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
Answer:
The volume of a given gas sample is directly proportional to its absolute temperature at constant pressure (Charles's law). The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (Boyle's law).
Answer:
The difference in the number of protons and neutrons in atoms account for many of the different properties of elements.