A mixture of $CaCO_3$ and $MgCO_3$ weighing 1.84 g on heating leaves a residue weighing 0.96 g. If the percentage by mass of $CaCO_3$ in the original mixture is x%, what is the value of x/2?

Which of the following contains the largest number of atoms?

Which of the following contains the maximum number of water molecules?

If Avogadro's number were redefined as $6.022 imes 10^{26} \, mol^{-1}$, which of the following would be directly affected?

Which of the following contains the greatest number of helium atoms?

How many moles are present in 18g of water (H2O)?

Which has more molecules: 1 mole of glucose or 18 grams of water?

A mixture of $1.2$ g formic acid and $2.25$ g oxalic acid is treated with conc. $H_2SO_4$. The evolved gaseous mixture is passed through $KOH$ pellets. Calculate the mass (in g) of the remaining product at STP.

Volume occupied by $3.01 imes {10^{23}}\;\;$ molecules of acetylene at NTP is:

If $4.6$ g of formic acid and $9.0$ g of oxalic acid react with concentrated $H_2SO_4$, and the resulting gaseous mixture is passed through $KOH$ pellets, what mass of gas (in grams) will remain at STP?

If you have 2 g of each of the following substances, which one would contain the highest number of atoms?