Fig. 1 shows a particle model of carbon dioxide released when a carbonate tablet is placed in water. Each circle represents one molecule. A student compares...
Question 1 Report
Fig. 1 shows a particle model of carbon dioxide released when a carbonate tablet is placed in water. Each circle represents one molecule. A student compares samples containing different numbers of molecules. Avogadro constant is 6.02 × 1023 molecules per mole. The particle model is not drawn to scale.
(a) Name the element represented by the central atom in each carbon dioxide molecule. [1]
(b) Use the formula CO2 to calculate its Mr. Ar values are C = 12 and O = 16. [2]
(c) Use Avogadro constant to calculate the number of molecules in 0.50 mol of carbon dioxide. [2]
(d) Give the number of oxygen atoms in 0.50 mol of carbon dioxide. [1]
Answer Details
(a) The central atom in each carbon dioxide molecule is carbon. [1]
(b) \[M_r(\text{CO}_2)=12+(2\times16)=44\] [2]
(c) \[0.50\times6.02\times10^{23}=3.01\times10^{23}\] There are \(3.01\times10^{23}\) molecules in \(0.50\text{ mol}\) of carbon dioxide. [2]
(d) Each \(\text{CO}_2\) molecule has two oxygen atoms, so: \[2\times3.01\times10^{23}=6.02\times10^{23}\] Number of oxygen atoms = \(6.02\times10^{23}\). [1]
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