25.0 cm3 of a 0.10 moldm-3 solution of sodium hydroxide was titrated against a solution of hydrochloric acid of unknown concentration. 27.3 cm3 of the acid was required. What was the concentration of the acid? 3. 25 cm3 of a solution of sodium hydroxide reacts with 15 cm3 of 0.1 mol/dm3 HCl.
2 marks 4 Draw the structural formula of Compound G. 1 mark 5 Using the chemical shift correlation for 13C NMR, predict the number of peaks for Compound G and draw in the position of the peaks on the blank spectrum below, annotating each peak with its corresponding structure. (2 marks) 6 Draw the structural formula for 2-chloro but-2-ene. Below this draw a structural formula of an isomer of 2-chloro but-2-ene and name this substance.
This reaction can be summed up using the following formula: 5Fe2++8H++MnO4- →5Fe3++Mn2++4H2O After standardization, the potassium permanganate solution is then titrated with 3 different magnesium oxalate solutions. To find the concentration of the C2O42- the balanced net ionic redox reaction formula is used: 5C2O42-+16H++2MnO4- →10CO2+2Mn2++8H2O It is important to note the addition of sulfuric acid (9M H2SO4) in performing this experiment because of the following reasons: 1) Sulfuric acid keeps the iron (II) from air oxidizing into iron (III) 2) Sulfuric acid keeps the iron (II) from hydrolyzing into Fe(OH)2 3) Sulfuric
(2 points) Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq) 2. Determine the partial pressure of the hydrogen gas collected in the gas collection tube. (3 points) partial pressure H2 = total pressure - vapor pressure of water = 746mmHg - 19.8mmHg = 726mmHg 3. Calculate the moles of hydrogen gas collected. (4 points) n = 125 4.
Aim : a) To determine reduction potentials of several redox couples. b) To determine the effect of concentration changes on cell potential. c) To determine the molar concentration of Cu2+ in the unknown using Nernst equation. Procedure : Please refer to the laboratory manual page 77 – 79. Results : Reduction Potentials of Several Redox Couples Galvanic Cell Measured Ecell Anode Equation for Anode Reaction Cathode Equation for Cathode Reaction Cu-Zn +1.19 V Zn Zn → Zn2+ + 2e- Cu Cu2+ + 2e- → Cu Cu-Mg +3.23 V Mg Mg → Mg2+ + 2e- Cu Cu2+ + 2e- → Cu Cu-Fe +0.89 V Fe Fe → Fe2+ + 2e- Cu Cu2+ + 2e- → Cu Zn-Mg +2.00 V Mg Mg → Mg2+ + 2e- Zn Zn2+ + 2e- → Zn Fe-Mg +1.54 V Mg Mg → Mg2+ + 2e Fe Fe2+ + 2e → Fe Zn-Fe +0.29 V Zn Zn → Zn2+ + 2e- Fe Fe2+ + 2e- → Fe Balanced net reaction Cu-Zn Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s) Cu-Mg Mg (s) + Cu2+ (aq) → Mg2+ (aq) + Cu (s) Cu-Fe Fe (s) + Cu2+ (aq) → Fe2+ (aq) + Cu (s) Zn-Mg Mg (s) + Zn2+ (aq) → Mg2+ (aq) + Zn (s) Fe-Mg Mg (s) + Fe2+ (aq) → Mg2+ (aq) + Fe (s) Zn-Fe Zn (s) + Fe2+ (aq) → Zn2+ (aq) + Fe (s) Zn-Mg = + 2.00 V, Mg-Cu = + 3.23 V The cell potential of Zn-Cu = 3.23 V – 2.00 V = 1.23 V The measured cell potential of Zn-Cu = +1.19 V The value of the sum of the Zn-Mg and Zn-Cu cell potentials are nearly the same as the Cu-Mg cell potential.
93 g/mol? Not we get to use it! Yay! 93 g/mol / 31.06 g/mol = 3 (this is the multiplier) Multiply that whole number through the subscripts of the empirical formula. 3 x (C H5 N) = C3H15N3 Hydrated compounds Solving process: 1st- the difference between the initial mass and that of the dry sample is the mass of water that was driven off.
Which would have the longer wavelength, light with a frequency of 4.5 X 1014 Hz or light with a frequency of 6.19 X 1014 Hz? (4.5 X 1014 Hz) ______________12. Find the frequency of light if its wavelength is 7.3 X 105 5 picometers. (4.1 X 1014 Hz) ______________13. Find the wavelength in centimeters of light whose frequency is 7.00 X 1016 Hz.
Use a calorimeter to measure the temperature change in each of three reactions. Calculate the heat of reaction, ∆H, for the three reactions. Use the results to confirm Hess’s law. Ev al Figure 1 ua tio Na+(aq) + OH–(aq) + H+(aq) ) + Cl–(aq) → H2O(l) + Na+(aq) + Cl–(aq) ∆H3 = ? n (3) Solutions of aqueous sodium hydroxide and hydrochloric acid react to form water and aqueous sodium chloride.
EXPERIMENT 11 Molar Mass of a Volatile Liquid DATA Run | UNKNOW | Mass of flask and foil(g) | 90.085g | Mass of flask and foil and condensed vapor (g) | 90.640g | Temperature of boiling water (˚C ) | 98˚C | Barometric pressure (torr) | 761mm Hg | Volume of flask (mL) | 140 mL | RESULTS Mass of unknown ( condensed vapor) | 0.555g | Volume of flask (vapor)(L) | 0.14 L | Temperature of vapor(k) | 371K | Molar mass of unknown (g/mole) | 118.380 g/mole | Advance Study Assignment 1) How would each of the following errors affect the outcome of this experiment? Would it make the molar mass high or low? Give your reasoning in three sentences or less in each case. a) The hole in the aluminum foil was quite large. if you were to have a larger hole in your aluminum cap, you would be losing vapor to the room.
EXPERIMENT 6 Title Kinetics of Chemical Reaction – Iodination of Cyclohexanone Aim To determine the value of the rate constant, k and order of reaction, a, b and c, and also to suggest a mechanism which agrees with the rate equation that has been obtained. Background Theory The basis of the theory of absorbance is as follows: Io ―――――→ sample ―――――→I if Io = I, no absorbance occur Io > I, the sample absorbs certain amount of light wave Io < I, the sample emits certain amount of light of certain wave length. THE HALOGENATION (IODINATION) OF KETONES (CYCLOHEXANONE) This experiment examined the rate of iodination of cyclohexanone in an aqueous medium. To increase the amount of iodine in the solution, iodine is converted to a more soluble complex ion, I3- by the addition of excess iodide ion: I2 + I- →I3- One of the characteristic reactions of ketones is the substitution of a halogen for one of the hydrogen is adjacent to the ketone group. The net reaction is: This reaction has been studied extensively and occurs for a wide variety of ketones.