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Quiz – The mole

The ability to complete calculations using moles is very important in chemistry. Test yourself with a quiz.

Your turn – mole calculations

  1. Aspirin has the formula \(\ce{C}_{9}\ce{H}_{8}\ce{O}_{4}\). Calculate the mass of aspirin in grams present in \(0.650\textrm{ mol}\) of aspirin. The molar masses of \(\ce{C}\), \(\ce{H}\) and \(\ce{O}\) are \(12.01\textrm{ g mol}^{–1}\), \(1.01\textrm{ g mol}^{–1}\), and \(16.00\textrm{ g mol}^{–1}\), respectively.

\(117\textrm{ g}\)

  1. Calculate the amount of \(\ce{C}\), \(\ce{H}\) and \(\ce{O}\), in moles, present in \(1.5\textrm{ mol}\) of glucose. The chemical formula of glucose is \(\ce{C}_{6}\ce{H}_{12}\ce{O}_{6}\).

\(N(\ce{C})=9.0\textrm{ mol}\)

\(N(\ce{H})=18\textrm{ mol}\)

\(N(\ce{O})=9.0\textrm{ mol}\)

  1. Calculate the mass of carbon in grams present in \(1.8\textrm{ g}\) of glucose. The chemical formula of glucose is \(\ce{C}_{6}\ce{H}_{12}\ce{O}_{6}\). The molar masses of \(\ce{C}\), \(\ce{H}\) and \(\ce{O}\) are \(12.01\textrm{ g mol}^{–1}\), \(1.01\textrm{ g mol}^{–1}\), and \(16.00\textrm{ g mol}^{–1}\), respectively.

\(0.72\textrm{ g}\)

  1. Calculate the number of hydrogen atoms present in \(1.5\textrm{ mol}\) of hydrogen.

\(9.0\times10^{23}\textrm{ atoms}\)

  1. Caffeine is an ingredient in coffee and tea that acts as a central nervous system stimulant. The chemical formula of caffeine is \(\ce{C}_{8}\ce{H}_{10}\ce{N}_{4}\ce{O}_{2}\).
    1. Calculate the molar mass of caffeine. The atomic masses are: \(\ce{C}=12.01\textrm{ amu}\), \(\ce{H}=1.01\textrm{ amu}\), \(\ce{O}=16.00\textrm{ amu}\), and \(\ce{N}=14.01\textrm{ amu}\).

    \(194.1\textrm{ g mol}^{–1}\)

    1. Calculate the number of molecules of caffeine present in a \(970.95\textrm{ g}\) sample of caffeine.

    \(5.002\textrm{ mol}\)

  1. Calculate the mass in grams of a \(1.2\textrm{ mol}\) sample of \(\ce{CO}_{2}\). The molar masses of \(\ce{C}\) and \(\ce{O}\) are \(12.01\textrm{ g mol}^{–1}\), \(16.00\textrm{ g mol}^{–1}\), respectively.

\(53\textrm{ g}\)

  1. A balloon filled with helium gas contains \(1.505\times10^{26}\) atoms of helium. Determine the mass of helium present inside the balloon. The molar mass of \(\ce{He}=4.00\textrm{ g mol}^{–1}\).

\(1000\textrm{ g}\)

  1. Ribose is a simple sugar present in RNA, the molecule involved in protein synthesis in living organisms. Ribose has the chemical formula \(\ce{C}_{5}\ce{H}_{10}\ce{O}_{5}\). Calculate the amount of \(\ce{C}\), \(\ce{H}\) and \(\ce{O}\) present in \(0.8\textrm{ mol}\) of ribose sugar.

\(n(\ce{C})=4\textrm{ mol}\)

\(n(\ce{H})=8\textrm{ mol}\)

\(n(\ce{O})=4\textrm{ mol}\)

  1. Calcium phosphate, \(\ce{Ca}_{3}\left(\ce{PO}_{4}\right)_{2}\), is an essential mineral present in the bones of many living organisms. Calculate the number of formula units of calcium phosphate present in \(31.02\textrm{ g}\) of calcium phosphate sample. The molar masses of \(\ce{Ca}=40.08\textrm{ g mol}^{–1}\), \(\ce{P}=30.97\textrm{ g mol}^{–1}\), and \(\ce{O}=16.00\textrm{ g mol}^{–1}\).

\(6.022\times10^{22}\textrm{ formula units}\)

  1. Chlorofluorocarbons have been used as refrigerants for many years. \(\ce{CFC}\textrm{-}12\) is one chlorofluorocarbon with the chemical formula \(\ce{CCl}_{2}\ce{F}_{2}\). Determine the mass of chlorine present in \(12.9\textrm{ g}\) of a \(\ce{CFC}\textrm{-}12\) sample. \(M(\ce{CFC}\textrm{-}12)=120.91\textrm{ g mol}^{–1}\) and \(M(\ce{Cl})=35.45\textrm{ g mol}^{–1}\).

\(7.56\textrm{ g}\)

  1. Keratin is a fibrous protein found in our skin, hair and nails. It has the chemical formula \(\ce{C}_{28}\ce{H}_{48}\ce{N}_{2}\ce{O}_{32}\ce{S}_{4}\). A sample of keratin contains \(0.71\textrm{ g}\) of \(\ce{N}\). Determine the mass of \(\ce{O}\) present in the sample if the molar mass of \(\ce{N}\) is \(14.01\textrm{ g mol}^{–1}\) and \(\ce{O}\) is \(16.00\textrm{ g mol}^{–1}\).

\(13\textrm{ g}\)

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