Blog

What volume of 0.09945M H3PO4 in mL, is required to neutralize 40.00 mL of 0.1315 M NaOH?      Hint: write the balanced equation first

Consider the data table below to calculate the enthalpy of reaction for the neutralization of nitric acid by barium hydroxide.   Volume   of 1.021MHNO3,  mL 50.00 60.00 70.00 80.00 90.00 100.0 Volume of 0.572MSr(OH)2, mL 100.0 90.00 80.00 70.00 60.00 50.00 Change of temperature, oC 4.54 5.45 6.36 7.27 6.54 5.46 Analyze the Data Table to find the highest temperature and answer the following questions. Consider the density of the solutions to be the same as water, 1.00 g/mL, both before and after mixing, and the heat capacity is the same as for water, 4.18J/oCg.  Since your calculators may give you slightly different numbers, pick the closest answer. The highest temperature change in oC[temp]  Number of moles of acid  at the highest temperature (at stoichiometric ratio)[molesA] Number of moles of the base  at the highest temperature (at stoichiometric ratio)[molesB] Mole fraction of acid and mole fraction of base at the highest temperature (at stoichiometric ratio)[MF] Stoichiometric mole ratio for the reaction: moles acid/moles base, calculated [MR] Stoichiometric mole ratio for the reaction: moles acid/moles base, rounded to the whole number[MR2] Heat absorbed by the solution in the calorimeter, J[q] Heat in kJ produced by the reaction between solutions of acid and base in the calorimeter[q2] Heat of reaction in kJ per number of moles of base[H] Thermochemical equation and Enthalpy of the neutralization reaction (Hint: Enthalpy is per number of moles of water)[Eq] Show work for Partial Credit, take a picture of your work, save it to your Canvas files, and upload your answer in the Work and Calculations assignment provided.

Balance the following reaction and determine the coefficient for water. __P2O5(g) +  __H2O(l) →  __H3PO4(aq)

Why the temperature remains constant during the phase changes? 

  Apply the Hess’s Law and use the Data table below to calculate the ΔH°rxn, in kJ, for: Sr(OH)2(s) + 2HNO3aq) => Sr(NO3)2(aq) + 2H2O(l) Show work for Partial Credit: take a picture of your work, save it to your Canvas files, and upload your answer in the Work and Calculations assignment provided. Substance  ΔHf° (kJ mol–1) Sr(OH)2(aq) -1007.3 HNO3(aq) -206.63 Sr(NO3)2(aq) -962.32 H2O (l) -285.83  

If 20.0 mL of 0.200 M Ca(OH)2reacted with 0.200 M HC2H3O2, what volume of acetic acid is required to neutralize the base?           Hint: write the balanced equation first

16.00 ml of 0.50 M HCl reacts with 6.00 mL of 0.50 M Ba(OH)2 in a stoichiometry study using the methods of continuous variations. The stoichiometry of the system was shown by the following balanced equation: Ca(OH)2(aq) + 2HCl(aq) → CaCl2(aq) + 2H2O(l) On the basis of the limiting reagent, calculate the theoretical number of moles of product (BaBr2) that should have been formed.

Write and balance the equation and determine the mole ratio of reactants. Use this information to answer the following questions: How many moles of NaOH are present in 255 mL of 2.7471M solution?[A] How many moles of H3PO4 are needed to completely neutralize this base?[B]

Balance the following reaction and determine the coefficient for water. __H2SO4(aq) + __Fe(OH)3(s) → __Fe2(SO4)3(aq) + __H2O(l)

A sample of gas occupies a volume of 160.0 L at 155° What will be the volume of gas in mL when the temperature drops to 55° C at the same pressure?