Assuming that 50% of the heat is useful, how many kg of water at 15.0 oC can be heated to 95.0 oC by burning 200L of methane, CH4, measured at STP? Heat of combustion of methane is 211 kcalmol-1. Specific heat capacity of water is 1.00 kcal kg-1K-1

NaCl(s) + H₂O(1)→→→>NaCl(aq) If sufficient NaCl dissolves in water to form 1.00 L of 2.00 mol/L NaCl solution, the change in enthalpy of the system is Select one: O a. +1.67 kJ O b. +2.50 kJ O c. +3.34 kJ O d. +8.35 kJ Aso1 +1.67 kJ/mol

Calorimetery practical 7:   Q= Calculate the enthalpy of neutralization for ( in units of kJ/mol H2O formed ) for both HCl and HAc. Use all parts : a, b and c.   [Must use the normal equation and equation: (Specific heat capacity of water x mass of water x change in temp of water ) / (mass of metal x change in temp of water )]       Part A Mass of metal (g) - 10.254 Temperature of boiling water bath (°C) 100.4 Mass of calorimeter (g) 4.044 Mass of calorimeter and water (g) 20.519 Time-zero from graph (s) 45.0 Initial temperature of water from graph(°C) 22.3 Final temp = 29.2 Equation of extrapolation curve from graph-  y = –0.0047291x + 29.2     Part B Molarity of NaOH (M) 1 Molarity of HCl (M) 1.1 Mass of calorimeter (g) 3.403 Volume of HCl (mL) 50.0 Volume of NaOH (mL) 50.0 Time-zero from graph (°C) 35.5 Initial temperature of mixture from graph(°C) 22.2 Final temperature 29.3 Equation of extrapolation curve from graph y = –0.0017787x + 29.3 Mass of calorimeter and mixture (g)…

19. Solid urea, (NH2)2CO, burns to give CO2, N2, and liquid H2O. Its heat of combustion is -632.2 kJ/mol. 1.Write the balanced combustion equation. Record fractions as ratios (e.g. 1/2) if needed. Include aggregation states in your answer. 2.Calculate the heat generated per mole of H2O formed to 0.1 kJ.  3.Using this heat of combustion and the appropriate thermodynamic data, determine the heat of formation of urea to 0.1 kJ.

Consider the following equation:  CH4 + 02 -> H2O + CO2 +890 kJ 1. Balance the Equation 2. How much heat is released when 5.50L of oxygen is reacted with methane at STP? 1 mole of oxygen will occupy 22.4L at STP (standard temperature and pressure (0 degrees celsius) and standard pressure (1atm)).

A 248.9 g sample of water at 27.8°C is heated to steam at 146.5°C. How much heat was absorbed? kcal B

A student experimentally determines the gas law constant, R, by reacting a small piece of magnesium with excess hydrochloric acid and then collecting the hydrogen gas over water in a eudiometer. Based L-atm on experimentally collected data, the student calculates R to equal 0.0832 mol·K L-atm Ideal gas law constant from literature: 0.08206 mol·K (a) Determine the percent error for the student's R-value. Percent error = % (b) For the statements below, identify the possible source(s) of error for this student's trial. The student notices a large air bubble in the eudiometer after collecting the hydrogen gas, but does not dislodge it. The student does not clean the zinc metal with sand paper. The student does not equilibrate the water levels within the eudiometer and the beaker at the end of the reaction. The water level in the eudiometer is 1-inch above the water level in the beaker. The student uses the barometric pressure for the lab to calculate R.

What is qH2O?

Given the following information, AH° (A2B(g)) = -225 KJ/mol AH (BC(g)) = -160 KJ/mol %3D AH (AC(g)) = -85 KJ/mol AH (B(g)) = -75 KJ/mol Determine AH° for the reaction, A2B(g) + 2BC(g) 2AC(g) + 3B(g) -600 KJ/mol 150 KJ/mol 600 KJ/mol 450 KJ/mol

9-2. Consider this thermochem ical equation: 4 PCh(1) → Pa(s) + 6 Ch(g) AH° = +1278.8 kJ If the chlorine gas is collected at STP, then what volume of chlorine is produced when 68 joules are absorbed in the reaction?