What is the root mean velocity of hydrogen gas (H2) at 30.00∘C ? Use R = 8.314 kg⋅m2 s2⋅mol⋅K for the ideal gas constant, and assume absolute zero is −273.15∘C. Your answer should have four significant figures. Provide your answer below: m/s
The heat of vaporization of water (H2O) is 539.2 cal g. How much energy in calories is absorbed when 94. g of water is vaporized? Be sure your answer has the correct number of significant figures.
The hydrogen selenate ion reacts with water according to the following reaction: HSeO4−(aq) + H2O(l) ⟷ SeO4−(aq) + H3O+(aq) Ka = 2.2×10−2 If 166.965 grams of sodium selenate (NaHSeO4) is dissolved in a total volume of 1.0 L, calculate the pH of the solution at equilibrium. (Answer with one, 1, significant figure)
Water gas is a 1:1 mixture of carbon monoxide and hydrogen gas and is called water gas because it is formed from steam and hot carbon in the following reaction: H2O(g) + C(s) ⇌ H2(g) + CO(g). Methanol, a liquid fuel that could possibly replace gasoline, can be prepared from water gas and hydrogen at high temperature and pressure in the presence of a suitable catalyst. What will happen to the concentrations of H2, CO, and CH3OH at equilibrium if more catalyst is added? (A) Catalyst will be contaminated (B) Nothing (C) Depends on the catalyst (D) Double
Water vapor (H2O) reacting with hot iron (Fe) produces Fe3O4 and H2 gas: 3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g) A mixture of 500.0 g iron and 150.0 g water vapor was allowed to react inside a sealed reaction chamber. (a) Which is the limiting reactant in this scenario? (b) What is the theoretical yield of Fe3O4(s) in grams?
The calcium content of urine can be determined by the following procedure: Ca2+ + C2O42− → CaC2O4 ⋅H2O(s) CaC2O4 ⋅H2O(s) + H+ → Ca2+ + C2O42− 5C2O42− + 2MnO4− + 16H+ → 10CO2 + 2Mn2+ + 8H2O How much calcium was originally present in the solution if the last step consumes 5.00 mL of 0.100 M permanganate solution? 0.00125 mol 0.200 mol 0.200 mmol 1.25 mol
Consider the reaction NH30(aq) + H2O(l) ⇌ NH4+(aq) + OH−(aq). Kb for NH30 is 1.8×10−5 at 25∘C. What is Ka for the NH4+ ion at 25∘C ? 5.6×104 5.6×10−10 1.8×10−5 7.2×10−12 9.2×10−8
Gaseous methane (CH4) will react with gaseous oxygen (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O). Suppose 9.30 g of methane is mixed with 23. g of oxygen. Calculate the minimum mass of methane that could be left over by the chemical reaction. Round your answer to 2 significant digits.
A sample of water (H2O) contains 3.61×1024 molecules. How many moles of atoms are present in this sample? 1.00 2.00 6.00 9.00
You have a sample of H2O with a mass of 23.0 g at a temperature of −46.0∘C. How many kilojoules (kJ) of heat energy are necessary to raise the temperature to 109⋅C ? Use the following data: Substance Heat of Fusion Heat of Vaporization H2O 6.01 kJ/mol 40.7 kJ/mol Specific Heat H2O(s) 2.06 J/g∘ CH2O(g) 2.02 J/g∘ CH2O(I) 4.18 J/g∘C
For the autoionization of water at 25.0∘C, the equilibrium constant is 1.012×10−14. H2O(l) ⇌ H+(aq) + OH−(aq) What is ΔG0 for the process? Round your answer to 4 significant digits. Note: Reference the Fundamental constants table for additional information.
Complete combustion of 15.62 g of a compound of carbon, hydrogen, and oxygen yielded 15.27 g CO2 and 3.126 g H2O. When 14.50 g of the compound was dissolved in 334 g of water, the freezing point of the solution was found to be −0.894∘C. For water, Kfp = 1.86∘C/m. What is the molecular formula of the compound? Enter the elements in the order C, H, O molecular formula =
When 5.171 grams of a hydrocarbon, CxHy, were burned in a combustion analysis apparatus, 15.84 grams of CO2 and 7.568 grams of H2O were produced. In a separate experiment, the molar mass of the compound was found to be 86.18 g/mol. Determine the empirical formula and the molecular formula of the hydrocarbon. Enter the elements in the order presented in the question. empirical formula = molecular formula =
Calculate the standard enthalpy change for the reaction at 25∘C. Standard enthalpy of formation values can be found in this list of thermodynamic properties. HCl(g) + NaOH(s) ⟶ NaCl(s) + H2O(l) ΔHrxn =
Starting with 165 g Li2O and 34.5 grams of H2O, which reactant will limit the reaction? Given: Li2O + H2O −− > 2LiOH
Hydrogen sulfide, a colorless gas with a foul odor, dissociates on heating: 2H2S(g) ⇌ 2H2(g) + S2(g) When 0.100 mol H2S was put into a 10.0−L vessel and heated to 1132∘C, it gave an equilibrium mixture containing 0.0285 mol H2. What is the value of Kc at this temperature?
What is the pH of a 0.41 M solution of Al(H2O)63+ if the Ka for the hydrate is 1.4×10−5 ? Round your answer to the nearest hundredth. Provide your answer below: pH =
During volcanic eruptions, hydrogen sulfide gas is given off and oxidised by air according to the following chemical equation: 2 H2S(g) + 3O2(g) → 2SO2(g) + 2H2O(g) Calculate the standard enthalpy change for the reaction above, given: 3S(s) + 2H2O(g) → 2H2S(g) + SO2(g) ΔHP = 162.9 kJ mol−1 S(s) + O2(g) → SO2(g) ΔH = −306.5 kJ mol−1
17-10. H2S(aq) is analyzed by titration with coulometrically generated I2 in Reactions 17−3 a and 17−3 b. To 50.00 mL of unknown H2S sample were added 4 g of KI. Electrolysis required 812 s at 52.6 mA. Find the concentration of H2S (μg/mL) in the sample.
Using the standard entropy tables Calculate ΔS∘ for the reaction 2H2S(g) + 3O2(g) −− > 2H2O(l) + 2SO2(g) Standard entropy (J/K) H2S(g) 205.8 O2(g) 205.2 H2O (I) 70.0 SO2(g) 248.2 −200.5 J/K −389.1 J/K 498.86 J/K 655.7 J/K −198.02 J/K
Hydrogen and hydrogen sulphide A container with volume of 100.0 L is empty. We charge 0.1 molH2 S and 0.1 molH2 into it. The container is sealed and heated to 1000∘C. Calculate PH2S × PH2 and PS2 at equilibrium. H2S = H2 + 1/2 S2 △G∘ = 27380 J at 1000∘C
Consider the following balanced chemical equation: 2H2O(g) + 2SO2(g) ⟷ 2H2S(g) + 3O2(g) A reaction mixture initially contains 3.2 M H2O and 2.6 M SO2. Determine the equilibrium concentration of H2S if Kc for the reaction at this temperature is 1.3×10−6.
For the reaction 2H2S(g) + 3O2(g) → 2H2O(l) + 2SO2(g) ΔH∘ = −1124.0 kJ and ΔS∘ = −390.7 J/K The standard free energy change for the reaction of 2.47 moles of H2 S(g) at 347 K, 1 atm would be kJ. This reaction is favored under standard conditions at 347 K. Assume that ΔH∘ and ΔS∘ are independent of temperature.
The equilibrium constant, Kp, for the following reaction is 0.110 at 298 K. NH4HS(s) ⇌ NH3(g) + H2S(g) If ΔH∘ for this reaction is 92.7 kJ, what is the value of Kp at 420 K ? Kp =
Most of the sulfur used in the United States is chemically synthesized from hydrogen sulfide gas recovered from natural gas wells. In the first step of this synthesis, called the Claus process, hydrogen sulfide gas is reacted with dioxygen gas to produce gaseous sulfur dioxide and water. Suppose a chemical engineer studying a new catalyst for the Claus reaction finds that 452. liters per second of dioxygen are consumed when the reaction is run at 167. ∘C and the dioxygen is supplied at 0.98 atm. Calculate the rate at which sulfur dioxide is being produced. Give your answer in kilograms per second. Be sure your answer has the correct number of significant digits.