Problem 607
If the atomic weight of carbon 12 is exactly 12 amu, find the mass of a single carbon-12 atom.
Problem 608
The atomic weight of iron is \(55.847\) amu. If one has \(6.02 \mathrm{~g}\) of iron, how many atoms are present?
Problem 609
Nitrogen reacts with hydrogen to form ammonia \(\left(\mathrm{NH}_{3}\right)\). The weight-percent of nitrogen in ammonia is \(82.25\). The atomic weight of hydrogen is \(1.008 .\) Calculate the atomic weight of nitrogen.
Problem 610
John Dalton found water to be \(12.5 \%\) hydrogen by weight. Calculate the atomic weight of oxygen if Dalton assumed water contained two hydrogen atoms for every three oxygen atoms. Assume \(1 \mathrm{H}\) atom weighs 1 amu.
Problem 611
On the basis of valence, predict the formulas of the compounds formed between the following pairs of elements: (a) Sn and F. (b) P and H. (c) Si and \(\mathrm{O}\).
Problem 613
The faint light sometimes seen over Marshland at night, the "will-o'-the- wisp", is believed to come about as a result of the burning of a compound of phosphorus (P) and hydrogen (H). What is the formula of this compound?
Problem 614
\(\mathrm{H}_{2} \mathrm{O}_{3}\), hydrogen trioxide, a close relative of hydrogen peroxide, has recently been synthesized. It is extremely unstable and can be isolated only in very small quantities. Write a Lewis electron dot structure for \(\mathrm{H}_{2} \mathrm{O}_{3}\)
Problem 615
Using electron-dot notation, show for each of the following the outer shell electrons for the uncombined atoms and for the molecules or ions that result: (a) \(\mathrm{H}+\mathrm{H} \rightarrow\) Hydrogen molecule (b) \(\mathrm{Br}+\mathrm{Br} \rightarrow\) bromine molecule (c) \(\mathrm{Br}+\mathrm{Cl} \rightarrow\) bromine chloride (d) \(\mathrm{Si}+\mathrm{F} \rightarrow\) silicon fluoride (e) \(\mathrm{Se}+\mathrm{H} \rightarrow\) hydrogen selenide (f) \(\mathrm{Ca}+\mathrm{O} \rightarrow\) calcium oxide
Problem 616
The sulfate ion consists of a central sulfur atom with four equivalent oxygen atoms in a tetrahedral arrangement. Keeping in mind the octet rule, draw the electronic structure for the ion. What should the internal \(\mathrm{O}-\mathrm{S}-\mathrm{O}\) bond angle be?
Problem 617
Distinguish a metallic bond from an ionic bond and from a covalent bond.
