Find the rms speed and the average kinetic energy of a hydrogen atom at a temperature of $10^7 \mathrm{~K}$. (At this temperature, which is of the order of the temperature in the interior of a star, the hydrogen is ionized and consists of a single proton.)

What type of molecule is formed when a halogen combines with hydrogen?

Boron and hydrogen form a number of compounds called boranes (see Interchapter I). A certain borane is found to contain 85.63% boron by mass, the rest being hydrogen. What is the empirical formula of the borane?

Given that $2.22 \times 10^{22}$ molecules of hydrogen sulfide dissolve in 450.0 milliliters of solution, draw a mole concept map and calculate the following.

grams of hydrogen sulfide gas dissolved in the solution

a. Will a photon of energy $5 \mathrm{eV}$ likely be absorbed by a hydrogen atom originally in its ground state? b. What is the range of photon wavelengths that could ionize a hydrogen atom that is originally in its ground state? c. What is the range of photon wavelengths that could ionize a hydrogen atom that is originally in its $n=2$ energy state?

Hydrogen gas and chlorine gas in the presence of light react explosively to form hydrogen chloride

$$\mathrm{H}_2(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{HCl}(\mathrm{g})$$

The reaction is strongly exothermic. Would an increase in temperature for the system tend to favor or disfavor the production of hydrogen chloride?

A thick part made of nickel is put into a room filled with hydrogen at 3 atm and $85^\circ C.$ Determine the hydrogen concentration at a depth of 2-mm from the surface after 24 h.

Weather balloons are filled with hydrogen and released at various sites to measure and transmit data about conditions such as air pressure and temperature. A weather balloon is filled with hydrogen at the rate of $0.5 \ \mathrm{ft}^3 / \mathrm{s}$. Initially, the balloon contains $2 \ \mathrm{ft}^3$ of hydrogen.

(a) Find a linear function $V$ that models the volume of hydrogen in the balloon at any time $t$.

(b) If the balloon has a capacity of $15 \ \mathrm{ft}^3$, how long does it take to completely fill the balloon?

In the movie Die Hard: With a Vengeance, Bruce Willis and Samuel L. Jackson are given a 5-gallon jug and a 3-gallon jug and they must put exactly 4 gallons of water on a scale to keep a bomb from exploding. Explain how they could accomplish this feat.

The $H_2/O_2$ fuel cell converts elemental hydrogen and oxygen into water, producing, theoretically, 1.23 V. What is the most sustainable way to obtain hydrogen to run a large number of fuel cells? Explain.

Weights of atoms and molecules are measured in atomic mass units (u). A molecule of C2H6 (ethane) is made up of 2 carbon atoms and 6 hydrogen atoms and weighs 30.07 u. A molecule of C3H8 (propane) is made up of 3 carbon atoms and 8 hydrogen atoms and weighs 44.097 u. Find the weights of a carbon atom and a hydrogen atom.

The enthalpy change for the reaction of hydrogen gas with fluorine gas to produce hydrogen fluoride is $-542 \mathrm{~kJ}$ for the equation as written:

$$\mathrm{H}_2(g)+\mathrm{F}_2(g) \rightarrow 2 \mathrm{HF}(g) \Delta H=-542 \mathrm{~kJ}$$

a. What is the enthalpy change per mole of hydrogen fluoride produced?

Why can carbon and hydrogen form so many hydrocarbons?

Energy in the sun is produced by the fusion of four hydrogen atoms into a helium atom. The process involves several steps, but the net reaction is simply $4^1 \mathrm{H} \rightarrow{ }^4 \mathrm{He}+$ energy. Given this, you can say that
A. One helium atom has more mass than four hydrogen atoms.
B. One helium atom has less mass than four hydrogen atoms.
C. One helium atom has the same mass as four hydrogen atoms.