Which of the 2 reactants is the limiting reagent C. Calculate the mass of urea formed D. How much excess reagent is left at the end of the reaction E. If the actual yield of urea formed was 980g what is its yield % a. Ans. 2NH3 + CO2 ( (NH2)2CO + H2O (17) (44) (60) 637.2 1142 980 b. HN3 c. 1124g d. 318g of CO2 e. 87.2% 1b .Iron is reduced from a reaction between aluminium and iron (III) oxide at a temperature of 3000°C. In this reaction 124g of Al and 601g of iron (III) oxide are reacted. A. Write a balance equation for the above reaction B.
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. CH4 + 2O2 → CO2 + 2H2O When 80 g of methane is completely combusted, 220 g of carbon dioxide and 180 g of water are formed. (a) Why is the mass of carbon dioxide formed greater than the mass of methane burnt? (b) Calculate the mass of oxygen that reacted. (c) Calculate the mass of water formed when 20 g of methane undergoes complete combustion.
What volume of concentrated (18.0 M) sulfuric acid would be required to make each of the following? a. 1.25 L of 6.00 M solution Mconc x Vconc = Mdil x Vdil (18.0 M) x (Vconc) = (6.00 M) x (1.25 L) Vconc=0.417 L b. 575 mL of 0.100 M solution Mconc x Vconc = Mdil x Vdil (18.0 M) x (Vconc) = (0.100 M) x (0.575 L) Vconc=0.00319 L Acid-Base Titrations 5. Calculate the molarity of an HCl solution if 20.0 mL of it requires 33.2 mL of 0.150 M NaOH for neutralization.
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.
• 5.01 x 1022 C atoms • 2.76 x 1023 C atoms • 3.31 x 1024 C atoms • 5.50 x 1023 C atoms How many Cl atoms are in 0.0728 g of PCl3? • 1.32 x 1023 Cl atoms • 3.19 x 1020 Cl atoms • 1.81 x 1024 Cl atoms • 9.58 x 1020 Cl atoms Calculate the molar mass of (NH4)2SO4 • 114.11 g/mol • 228.22 g/mol • 132.15 g/mol • 118.14 g/mol 2. Calculate the mass of 4.50 moles of Ca3PO4 • 215 g • 968 g • 87.1 g • 392 g 3. The mineral pyrolusite is a compound of 55Mn and 16O. If 63% of the mass of pyrolusite is due to manganese, what is the empirical formula of pyrolusite?
The temperature rose from 25.0°C to 34.9°C. Calculate the heat capacity, molar heat capacity and the specific heat capacity. 5) From the enthalpies of reaction N2(g) + O2(g) 2NO(g) 2NO(g) + O2(g) 2NO2(g) 2N2O(g) 2N2(g) + O2(g) H = 180.7 kJ H = -113.1 kJ H = -163.2 kJ calculate H for the reaction of dinitrogen monoxide with nitrogen dioxide: N2O(g) + NO2(g) 3NO(g) 6) a. b. Give the electronic configuration for Sn. Give the abbreviated electronic configuration for Ti.
1) Calculate the number of moles in each of the following solutions:- a) 2.0 dm3 of 0.050 mol.dm-3 hydrochloric acid b) 50 dm3 of 5 mol.dm-3 sulfuric acid c) 10 cm3 of 0.25 mol.dm-3 potassium hydroxide  2) Calculate the volume in cm3 of each solution that contains the following numbers of moles:- a) 0.00500 moles of NaOH with concentration 0.100 mol.dm-3 b) 1.00×10-5 moles of HCl with concentration 0.0100 mol.dm-3 c) 9.25×10-3 moles of KCl with concentration 0.250 mol.dm-3  3) Find the concentrations of the following solutions in both mol.dm-3 and g.dm-3:- a) 0.400 moles of HCl in 2.00 dm3 of solution b) 12.5 moles of H2SO4 in 5.00 dm3 of solution c) 1.05g of NaOH in 500 cm3 of solution  4) In a titration, 25.0 cm3 of a solution of sodium hydroxide required 18.80 cm3 of hydrochloric acid of concentration 0.0500 mol.dm-3 for neutralisation. Find the concentration of the sodium hydroxide in both mol.dm-3 and g.dm-3.  NaOH + HCl ( NaCl + H2O 5) Calculate the volume of 0.05 mol.dm-3 potassium hydroxide solution that is required to react exactly with 25.0 cm3 of 0.0150 mol.dm-3 nitric acid.  HNO3 + KOH ( KNO3 + H2O 6) In a titration, 20.0 cm3 of barium hydroxide solution required 28.60 cm3 of sulfuric acid of concentration 0.0250 mol.dm-3 for neutralisation. Find the concentration of the barium hydroxide in both mol.dm-3 and g.dm-3.
14.1 Multiple-Choice and Bimodal Questions 1) Consider the following reaction: [pic] The average rate of appearance of B is given by[pic]. Comparing the rate of appearance of B and the rate of disappearance of A, we get [pic] A) -2/3 B) +2/3 C) -3/2 D) +1 E) +3/2 Answer: B Diff: 1 Page Ref: Sec. 14.2 2) Nitrogen dioxide decomposes to nitric oxide and oxygen via the reaction: [pic] In a particular experiment at 300 °C, [pic]drops from 0.0100 to 0.00650 M in [pic] The rate of appearance of [pic] for this period is __________ M/s. A) [pic] B) [pic] C) [pic] D) [pic] E) [pic] Answer: A Diff: 1 Page Ref: Sec. 14.2 3) Which substance in the reaction below either appears or disappears the fastest?
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.