Calcium carbonate forms limestone, one of the most common rocks on Earth. It also forms stalactites, stalagmites, and many other types of formations found in caves. When calcium carbonate (CaCO3) is heated, it decomposes to form solid calcium oxide and carbon dioxide gas. Write the balanced equation and calculate how many liters of carbon dioxide will be produced at STP if 2.38 g of calcium carbonate reacts completely?

  , 0.533 L

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

According to avogadro's law, 1 mole of every substance occupies 22.4 L of volume at STP.

Number of moles =

moles of calcium carbonate =

As 1 mole of calcium carbonate produces = 22.4 L of carbon dioxide at STP

Thus 0.0238 moles of calcium carbonate produces = of carbon dioxide at STP

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.