Who is right, John or Anna? Explain your answer. 3 When 200 g of calcium nitrate, Ca(NO3)2.2H2O is heated at 120ºC the mass decreases by 36 g. (a) Why does the mass decrease? (b) How much calcium nitrate is left after heating? 4 Calculate the molar mass of these compounds: (relative atomic masses: H = 1; N = 14; O = 16; S = 32; Cu = 64; Br = 80; Pb = 207) (a) copper nitrate, Ca(NO3)2 (b) lead bromate, Pb(BrO3)2 (c) ammonium sulfate, (NH4)2SO4 5 The equation for the complete combustion of methane is shown below.
Calculate the molarity of an HCl solution if 20.0 mL of it requires 33.2 mL of 0.150 M NaOH for neutralization. 7. Calculate the molarity of a Ca(OH)2 solution if 18.5 mL of it requires 28.2 mL of 0.0302 M HCl for neutralization. The products are CaCl2(aq) and H2O. 9.
When referring to mass sum of the atomic masses of the atoms represented by the formula of a molecular substance, the correct term used is A. atomic mass B. formula weight C. molecular mass D. molecular weight 12. A mole of CO2 contians A. 6.02 x 1023 ions C. 6.02 x 1023 formula ions B. 6.02 x 1023 molecules D. 6.02 x 1023 atoms 13. The mass of the products in a chemical reaction depends on the amount of A. excess reactant B. limiting reactant C. oxidizing agent D. reducing subtannce 14.
Abstract: The task of this experiment was to find the activation energy of the pseudo-first order of a hydrogen peroxide-Iodide reaction at 3 different temperatures; 273K, 293K and 303K. Using the arrhenius equation this value was found to be 46.71 J/mole in this experiment. Introduction This experiment focuses on using pseudo-first order kinetics to find the activation energy of a reaction. Psuedo-first order is were one of the reactants in the rate equation is present in great excess over the other in the reaction mixture. Pseudo first order reactions are used to find the rate constant of a second order reaction when one of your two components is very expensive and the other one is relatively inexpensive.
To find out how much acid was neutralized by single doses of each antacid we have to subtract the answers from question one from the moles of HCl (.004mol). Maalox: .004 -.001205= .002795 mol Tums: .004 - .00112 = .002880 mol Mylanta: .004 - .001 = .003 mol CVS brand: .004 - .000995 = .003005 mol Rennies: .004 - .00122 = .002780 mol Divide the number of moles of acid neutralized in each case by that antacid's mass. This gives you the moles of acid neutralized per gram of antacid, which will allow you to judge the strongest and weakest antacids on a per weight basis. Maalox: 24.1ml/20.0g = 1.21ml/g .002795 mol base / 20.0g = .00013975 mol base/pill Tums: 22.4ml/21.0g = 1.07ml/g .002880 mol base / 21.0g = .0001371 mol base/pill Mylanta: 20.0ml/18.0g = 1.11ml/g .003 mol base / 18.0g = .0001666 mol base/pill CVS brand: 19.9ml/18.3g = 1.09ml/g (.003005 mol base)/ (18.3g pill) = .0001642 mol base/pill Rennies: 24.4ml/ 17.5g = 1.39ml/g (.002780 mol base)/ (17.5g pill) = .0001588 mol base/pill
Comparing the rate of appearance of C and the rate of disappearance of A, we get[pic]. A) [pic] B) [pic] C) [pic] D) [pic] E) [pic] Answer: A Diff: 1 Page Ref: Sec. 14.2 A flask is charged with 0.124 mol of A and allowed to react to form B according to the reaction A(g) →B(g). The following data are obtained for [A] as the reaction proceeds: [pic] 5) The average rate of disappearance of A between 10 s and 20 s is __________ mol/s. A) [pic] B) [pic] C) [pic] D) 454 E) [pic] Answer: A Diff: 1 Page Ref: Sec.
Unknown acid buret | | | | Trial #1 | Trial #2 | Initial buret reading | 20.5 mL | 21.8 mL | Final buret reading | 40.5 mL | 45.1 mL | Volume of acid added | 20.0 mL | 23.3 mL | This second table shows the calculation of the pH at half equivalence point, average pKa and the average of the unknown acid. The volume of equivalence point was found by picking the steepest portion of the curve or point of inflection from the graph; and tracing the point to the volume NaOH added. One-half the equivalence point was determined by dividing by ½ of the volume of equivalence point. Once the one-half of the equivalence point was found, trace the point until you hit the graph line and trace it to the pH-axis. Results | | | | Trial #1 | Trial #2 | Volume of NaOH at equivalence point | 9.5 mL | 13.7 mL | Volume of NaOH at one-half the equivalence point | 4.75 mL | 6.9 mL | pH at half equivalence point | 5.42 | 5.3 | pKa of unknown acid | 5.42 | 5.3 | Average pKa | 5.36 | 5.36 | Average Ka | 4.4 * 10-6 | 4.4 * 10-6 | Moles of unknown acid | 1.30 * 10-3 moles | 1.87 * 10-3 moles | M of unknown acid | 0.0650 M | 0.0805 M | Average M of unknown acid | 0.07275 M | 0.07275 M | 2.
1. A solution containing 1.000M acetic acid (CH3COOH) and 1.000M ethyl alcohol (CH3CH2OH) at 150oC produced 0.171 mole/liter of the product ethyl acetate (CH3COOCH2CH3) when equilibrium was established. Determine Kc for the reaction. CH3COOH (aq) + CH3CH2OH (aq) CH3COOCH2CH3 (aq) + H2O (l) 2. Using the equilibrium constant from above, calculate the equilibrium concentrations of all the compounds in the reaction if 1.000M acetic acid is reacted with 2.000M ethyl alcohol.
Siddharth Rajendran Chemistry HL Urea Dissolution Lab Raw Data:- (Expected Values) Change in Enthalpy: 14 kJ mol-1 Change in Gibbs free energy: 6.86 kJ mol-1 Change in Entropy: 69.5 J mol-1 Molar Mass of Urea: 60.06 g mol-1 Heat Capacity: 4.184 J g-1º Data Table 1: To calculate the Enthalpy change Mass of Urea Tablet (g) (±0.01g) | Volume of Water(mL) (±0.05mL) | Initial Temperature (Cº) (±0.2 Cº) | Final Temperature(Cº) (±0.2 Cº) | 3.04 | 50.0 | 21.3 | 17.4 | Initial Observations:- * There was a decrease in temperature at a fast rate. * The temperature of the solution was slowing down continuously but the rate started decreasing. * The Urea dissolved and the rate was decreasing continuously. * The temperature gradually started to increase after almost the Urea present had dissolved. Data Table 2: Mass, Volume and Temperature during Dissolution of Urea (To calculate Keq) Mass of Urea(g) (±0.01g) | Initial Temperature(Cº) (±0.2 Cº) | Final TemperatureCº) (±0.2 Cº) | Initial Volume(mL)(±0.05 mL) | Final Volume(mL)(±0.05 mL) | 3.76 | 21.4 | 22.9 | 5.02 | 7.14 | Processing Raw Data * Determining the Final temperature of dissolution of Urea in the Styrofoam cup.