Pb (NO3) 2 10. A compound is 42.3 % C, 5.94 % H, 32.9 % N, and 18.8 % O and has a molecular mass of 425.25 g/mol. Calculate the empirical and molecular formula. C15H25N10O5 11. How many moles of Al2O3 are produced by the reaction 200. g Al?
0.05mol/6M=8.3*10-3 L=8.3mL stock solution c. 100mL-8.3mL=91.7mLwater Add 91.7 water to 6M stock solution to prepare 0.5M acetic acid. Exercise 8: a. 42.35 - 0.55 = 41.8 mL b. The moles of EDTA4- : 0.0189M*(41.8*10-3)L=7.9*10-4mol c. Zn2+(aq)+EDTA4-(aq)—Zn(EDTA)2-(aq) The ratio Zn2+ and EDTA4- is 1:1 The moles of Zn2+= the moles of EDTA4-=7.9*10-4mol d. 7.9*10-4mol*65.39g/mol=0.0517g Zn e.
Conclusion 10 Grams of Potassium chlorate when decomposed produces 3.915576 grams oxygen gas and 6.083363 grams potassium chloride Atomic Weight of Magnesium Introduction In this lab we will determine the atomic weight of magnesium by measuring the amount of hydrogen gas evolved when hydrochloric acid reacts with magnesium. The reaction is as follows: Mg + 2HCl -> H2 + Mg2+ (aq) + 2Cl- (aq) There is a one to one relationship between the number of moles of hydrogen gas evolved and the
Determine the percent yield of this reaction, showing all steps of your calculation. (3 points) heoretical yield of H2 gas: (1.156 x 10^-3 moles)(1 mole H2/ 1 mole Mg) = 1.156 x 10^-3 moles Theoretical mass: (1.156 x 10^-3 moles)(2.02 g/mole) = 2.335 x 10^-3 g Using ideal gas law: P = (1.1 atm)(760 torr / 1 atm) - 19.8 torr = 816.2 torr V = 0.026 L T = 295 K Solve for n: n = PV/(RT) n = (816.2 torr)(0.026
Calculate the value of Ke for this system. 2 H2S (g) === 2 H2 (g) + S2 (g) [1.1(10-4] 7. At a given temperature, the following system has an equilibrium constant, Ke, of 0.27. C(g) + B(g) === 2 E(g) The system was established by placing 8.00 moles of C and 5.0 moles of B in a 4.0 L vessel. Calculate the concentration of all substances at equilibrium.
29.4 atm B. 4.89 atm C. 25.1 atm D. 36.0 atm _____ 5. The vapor pressure of pure ethanol at 60 °C is 349 mm Hg. Calculate the vapor pressure at 60 °C of a solution prepared by dissolving 10.0 mol of naphthalene (nonvolatile) in 90.0 mol of ethanol. A.
2) Percent recovery for isolation of benzoic acid % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.43/1.01) x100% = 42.57% That concludes that the percent recovery is 42,57%. 3) Percent recovery for isolation of hydroquinone dimethyl ether % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.16/1.01) x100% = 15.84% That concludes that the percent recovery is 15.84%. Table 2: : Experimental IR peaks compared to literature IR peaks for Benzoic acid Functional groups | Experimental peak (cm-1) | Literature peak (cm-1) | O-H | 3407-2563 | 3400-2564 | C=O | 1689 | 1689 | C-H |
b) Calculate the enthalpy of combustion per gram of each sugar. C6H12O6 + 6O2 --> 6CO2 + 6H2O (-383.5 x 6 + -285.8 x 6) - (-1273) = -2742.8kJ C12H22O11 + 12O2 --> 12CO2 + 11H2O (-383.5x12 + -285.8x11) - (-2221) = -5524.8kJ -2742.8kJ / 180g/mole = -15.24kJ/g -5524.8kJ / 342g/mole = -16.14kJ/g 107. Three common hydrocarbons that contain four carbons are listed here, along wiht their standard enthalpies of formation: Formula Delta H in kJ per mol 1,3-Butadiene C4H6(g) 111.9 1-Butene C4H8(g) 1.2 n-Butane C4H10(g) -124.7 a. For each of these substances, calculate the molar enthalpy of combustion to CO2(g) and H2O(l). b.
Initial Concentration Chemical Mass of Graduated Cylinder (g) Mass of Sugar (g) Molar Mass (g) Moles in Graduated Cylinder Total Volume (L) Molarity (mol/L) Sugar (C12H22O11) 16.6 10 342.29 .29 .1 .29 Data Table 9. Dilution Series Dilution Volume (mL) Mass (g) Density (g/mL) Initial Concentration (M) Volume Transferred (mL) Final Concentration (M) 0 25.0 mL 25 25 0 mL 0ml 1 25.0 mL 10 10 .29 2.5 mL 5.4M 2 25.0 mL 15 40 .435 4.5 mL 6.8M 3 25.0 mL 20 45 .58 3.0 mL 9.4M 4 25.0 mL 25 50 7.25 6.0 mL 11.2M Data Table 10. Molarity vs. Density Molarity vs. Density molarity is the concentration of a solution given in gram moles of solute per liter of solution. Density is the degree of compactness of a substance. Questions: How would you prepare 10 mL of a 0.25M HCl solution if 1M HCl was available?
If the reaction is not spontaneous under standard conditions at 298K, at what temperature (if any) would the reaction become spontaneous? a) 2 PbS (s) + 3 O2 (g) → 2 PbO (s) + 2SO2 (g) ; ΔH° = -844 kJ; ΔS°= -165 J/K b) 2 POCl3 (g) → 2 PCl3 (g) + O2 (g) ; ΔH° = 572 kJ; ΔS°= 179 J/K 5. Consider the reaction H2 (g) + F2 (g) → 2 HF (g). a) Using data in your Appendix B, calculate ΔG° at 25°C b) Calculate ΔG at 298K if the reaction mixture consists of 8.0 bar of H2, 4.5 bar of F2 and 0.36 bar of HF. 6.