Problem 1
The \(C-C\) bond length in a crystal of diamond is 0.154 nm. What is this distance in (a) metres, (b) picometres, (c) angstroms? (Section \(1.2)\)
Problem 2
Oxygen gas liquefies at \(-183.0^{\circ} \mathrm{C}\) and freezes at \(-218.4^{\circ} \mathrm{C}\) Work out its melting point, \(T_{\mathrm{m}},\) and boiling point, \(T_{\mathrm{b}},\) in kelvin. (Section \(1.2)\)
Problem 3
A sealed flask holds \(10 \mathrm{dm}^{3}\) of gas. What is this volume in (a) \(\left.\mathrm{cm}^{3},(\mathrm{b}) \mathrm{m}^{3}, \text { (c) litres? (Section } 1.2\right)\)
Problem 4
What is the Sl derived unit for the speed of a molecule? (Section \(1.2)\)
Problem 5
How many moles of atoms are contained in the following masses: (a) \(22.0 \mathrm{g}\) of magnesium; (b) \(43.2 \mathrm{g}\) of chlorine (c) \(126 \mathrm{mg}\) of gold; (d) \(1.00 \mathrm{kg}\) of mercury? (Section 1.3 )
Problem 12
A stream running out from a copper mine contains a dilute solution of copper sulfate. As it passes over an iron grid, copper metal deposits on the grid. (Section \(1.4)\) (a) Write a balanced equation, with state symbols, for the reaction taking place. (b) Write an ionic equation for the reaction. (c) Assign oxidation states to the elements in each of the reactants and products in the equation in (b). Use these values to decide what has been oxidized and what reduced.
Problem 13
(a) What are the systematic names for \((0) \mathrm{CS}_{2} ;(\mathrm{il}) \mathrm{Cl}_{2} \mathrm{O}_{7}\) (iii) \(\mathrm{XeF}_{6} ;(\mathrm{iv})\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4} ;(\mathrm{v}) \mathrm{CrCl}_{3} ;(\mathrm{vi}) \mathrm{KlO}_{4} ?\) (b) Write the formula of each of the following compounds: (i) sodium sulfite; (ii) barium carbonate; (iii) iron(II) chloride; (iv) sodium thiosulfate; (v) diiodine pentoxide; (vil) dinitrogen oxide. (Section 1.4 )
Problem 14
In most compounds, H has an oxidation state of +1 and 0 has an oxidation state of \(-2 .\) The following compounds are exceptions to this rule. Assume each metal has the oxidation state of its most common ion and that \(F\) has an oxidation state of \(-1 .\) Find the oxidation state of \(\mathrm{H}\) or \(\mathrm{O}\) in each compound: (a) \(\mathrm{KO}_{2}\) (b) \(\mathrm{Na}_{2} \mathrm{O}_{2} ;(\mathrm{c}) \mathrm{MgH}_{2}\) (d) \(\mathrm{LiAIH}_{4}\) (e) \(\left.\mathrm{OF}_{2} \text { . (Section } 1.4\right)\)
Problem 15
Sodium chromate \(\left(\mathrm{Na}_{2} \mathrm{CrO}_{4}\right)\) can be prepared by oxidizing a chromium(lil) salt with sodium peroxide (Na_O_) in alkaline solution. The \(\mathrm{Cr}^{3+}\) ions are oxidized to \(\mathrm{CrO}_{4}^{2-}\) ions. The \(\mathrm{O}_{2}^{2-}\) ions are reduced to OH' ions. Construct half equations and a balanced overall equation for the reaction. (Section \(1.4)\)
Problem 16
To prepare a very dilute solution, it is more accurate to make up a more concentrated standard solution, and carry out a series of successive dilutions, than to weigh out a very small mass of the solute. A solution was made by dissolving \(0.587 \mathrm{g}\) of \(\mathrm{KMnO}_{4}\) in dilute sulfuric acid and making the volume of solution up to \(1 \mathrm{dm}^{3}\) in a volumetric flask. \(10.0 \mathrm{cm}^{3}\) of this solution were transferred to a second \(1 \mathrm{dm}^{3}\) volumetric flask and diluted to the mark with water. The dilution process was then repeated once, that is, \(10.0 \mathrm{cm}^{3}\) of this solution were transferred to a \(1 \mathrm{dm}^{3}\) volumetric flask and diluted to the mark with water. (Section 1.5 ). (a) What mass (in \(\mathrm{mg}\) ) of \(\mathrm{KMnO}_{4}\) would you have had to weigh out to make \(500 \mathrm{cm}^{3}\) of a solution with the same concentration as the final dilute solution? (b) What is the concentration of the final dilute \(\mathrm{KMnO}_{4}\) solution in moldm \(^{-3} ?\)
