A mixture of $KClO_3$ and $KCl$ weighing 4.96 g was heated to produce $O_2$. The evolved oxygen occupied 448 mL at STP. What percent of the original mixture was $KClO_3$?

A sample of chalk containing 75% $\mathrm{CaCO_3}$ by mass is heated. If 15 g of $\mathrm{CO_2}$ is produced, what was the initial mass of the chalk sample? (Atomic mass of $\mathrm{Ca} = 40$)

$\left[\mathrm{CaCO_3} \stackrel{\Delta}{\longrightarrow} \mathrm{CaO} + \mathrm{CO_2}\right]$

If 10 g of limestone with 50% purity is heated, what mass of $\mathrm{CO_2}$ is produced? (Atomic mass of $\mathrm{Ca} = 40$)

$\left[\mathrm{CaCO_3} \stackrel{1200 \mathrm{K}}{\longrightarrow} \mathrm{CaO} + \mathrm{CO_2}\right]$

If 4 g of NaOH is dissolved in 250 mL of water, what is the molarity of the solution?

What is the mass of one mole of water ($H_2O$)? (Atomic masses: H = 1u, O = 16u)

Upon heating 20 g of limestone with 20% purity, what mass of $\mathrm{CO_2}$ is produced? (Atomic mass of $\mathrm{Ca} = 40$)

$\left[\mathrm{CaCO_3} \stackrel{1200 \mathrm{K}}{\longrightarrow} \mathrm{CaO} + \mathrm{CO_2}\right]$

Calculate the number of moles of $\mathrm{CO_2}$ produced when 50 g of calcium carbonate containing 60% impurity is completely decomposed upon heating. (Atomic mass of $\mathrm{Ca} = 40$)

$\mathrm{CaCO_3} \rightarrow \mathrm{CaO} + \mathrm{CO_2}$

Calculate the number of atoms in 0.5 moles of sulfur (S). (Avogadro's Number = $6.022 imes 10^{23}$)

What is the molar mass of $CO_2$? (Atomic masses: C = 12u, O = 16u)

10 g of calcium carbonate ($CaCO_3$) on heating produces how many grams of calcium oxide ($CaO$)? (Atomic masses: Ca = 40, C = 12, O = 16)

How many moles are present in 32g of oxygen gas ($O_2$)? (Atomic mass of O = 16u)