Describe and explain (i) how the thermal stabilities of the Group 17 hydrides vary down the Group, from HCl to HI (li) how the volatilities of the halogens, from Fluorine to lodine, vary down Group 17.

The molecular speed of gas is related to the speed of sound, as sound vibrations cannot travel faster than the molecules that cause the pressure waves. If you and your friend were trying to speak to each other, on which planet would you have to stand closer to your friend to have a conversation, Venus or Earth? The predominant gas in Venus and Earth's atmosphere are carbon dioxide (CO₂) and nitrogen (N₂), respectively. Assume that the gases behave ideally and T = 25°C and 462°C for Earth and Venus, respectively.

Calculate the change in internal energy (in kcal) for the reaction Cl2(g) + 7/2 O2(g) = Cl₂O7(g) at 25 °C, given that the gases are ideal. The enthalpy, AH, for the formation of Cl₂O7(g) is 63.4 kcal mol- ¹ at 25 °C.

A 7.000 g sample of solid potassium chlorate is decomposed in the presence of the catalyst MnO2 to yield solid potassium chloride and oxygen gas. (MnO2 is written above the arrow of the chemical equation and is NOT used in any of the calculations. Remember, catalysts are not consumed by a chemical reaction; they only speed it up.) The oxygen gas is collected and stored in a 5.00 L gas tank ata temperature of 19.00oC. What is the pressure inside the tank?

A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at a barometric pressure of 101.4 kPa, if PHe  = 82.5 kPa and  PCO2  = 0.4 kPa?

A piece of metal weighing 0.713 g was placed in an eudiometer containing aqueous HCI. After the metal fully dissolved ,23.5 mL of hydrogen gas was collected by displacement of water and a 400 mm column of water was observed. The water temperature was 25 degrees Celcius and the barometric pressure was 758.8 mm Hg ( torr). Refer to the introduction and data sheet to solve the following problems. Calculate the pressure of the hydrogen gas above the water in the column. Calculate the volume occupied by the hydrogen gas at STP.How many equivalent weights (#ew) of the metal were consumed in the reaction? What is the equivalent weight of the metal?

3. One mole of liquid water at 100 °C is heated until the liquid is converted entirely to vapor at 100 °C and 1 atm pressure. Calculate q, w, AE and AH for each of the following. (a) The vaporization is carried out in a cylinder where the external pressure on the piston is maintained at 1 atm throughout. (b) The cylinder is first expanded against vacuum (Pext = 0) to the same volume as in part (a), and then sufficient heat is added to vaporize the liquid completely to 1 atm pressure.

The diagram below shows some isotherms of water. (a) S Estimate values for the critical constants and the van der Waals constants a and b for this gas. (b) Using the information from part (a), estimate the radius of a water molecule. Compare to the value of 1.37 A obtained from interpolation of ionic radii (Y. Zhang and Z. Xu, American Mineralogist 80 (1995) 670-675). PIMPa C 8 15- 10- M 50 400°C 374°C 350°C 300°C 425°C 450°C 275°C 100 150 200 250 300 350 Vicm mole 400 500

Ff.46.

The reduction of iron(III) oxide (Fe2O3) to pure iron during the first step of steelmaking, 2 FeO3(s) 4Fe(s) + 302(g) is driven by the high-temperature combustion of coke, a purified form of coal: C(s) + O2(g) → CO₂ (g) -> 11 ✓12 Suppose at the temperature of a blast furnace the Gibbs free energies of formation AG, of CO2 and Fe2O3 are -447. kJ/mol and -818. kJ/mol, respectively. Calculate the minimum mass of coke needed to produce 7800. kg of pure iron. Round your answer to 2 significant digits. kg 5