A newly made Styrofoam ball calorimeter was first calibrated by mixing 10.0 mL of 0.40 M hydrochloric acid and 0.1008 g magnesium oxide (MW = 40.30 g/mol; specific heat = 0.276 kJ/g°C). The reaction enthalpy (ΔHrxn) of HCl and MgO is -139.6 kJ/mol. The temperature change was recorded to be 5.5 °C. After calibration, the calorimeter was used to determine the reaction enthalpy of nitric acid and potassium hydroxide by mixing 5.0 mL of 0.40 M HNO3 and 5.0 mL of 0.80 M KOH. The temperature change was recorded to be 1.0 °C. What is the corrected heat capacity of the calorimeter?

You place 32.3 ml of 0.134 M Ba(OH), in a coffee-cup calorimeter at 25.00°C and add 60.6 ml of 0.433 M HCI, also at 25.00°C. After stirring, the final temperature is 28.63°C. {assume that the total volume is the sum of the individual volumes and that the final solution has the same density (1.00 g/ml) and specific heat capacity (4.184 J/g°C) as water}. Calculate the change in enthalpy, AH, of the reaction (in kJ/mol) of water formed. Enter the appropriate sign (+/-). Enter a number to 1 decimal place.

A quantity of 2.00×102 mL of 0.786 M HCl is mixed with 2.00×102 mL of 0.393 M Ba(OH)2 in a constant-pressure calorimeter of negligible heat capacity. The initial temperature of the HCl and Ba(OH)2 solutions is the same at 20.76°C. For the process below, the heat of neutralization is −56.2 kJ/mol. What is the final temperature of the mixed solutions?   H+(aq) + OH−(aq)→H2O(l)   _____°C

the molar heat capacity of iron is 25.10 J mol –1 K–1 . A 25.0 g ball is heated until it is glowing red (to a temperature of 400.°C). It is dropped into a 50.0 mL container of water at 25.0°C. If the density of water is 0.997 g mL–1 , and the molar heat capacity of water is 4.186 J g–1 K–1 , what temperature (in K) will the ball and water equilibrate to? A) 338 B) 300 C) 317 D) 359 E) 342

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 195.kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that 69.kJ of work is done on the mixture during the reaction.  Calculate the change in energy of the gas mixture during the reaction. Be sure your answer has the correct number of significant digits. Is the reaction exothermic or endothermic?

5.00 × 10−2 mol KOH and an excess of hydrochloric acid are combined in 100.0 mL of water initially at 25.0 °C, leading to a final measured temperature of 31.1 °C. (a) What is the heat flow for the water in the calorimeter, qH2O, in Joules? (b) Assuming the calorimeter constant Ccal = 50.0 J °C , what is the heat flow for the calorimeter, qcal, in Joules? (c) What is the amount of heat given off by the reaction, qrxn, in Joules? (d) What is the molar enthalpy of the neutralization reaction (shown below) as measured in the calorimeter, ∆H◦ rxn in kilojoules per mole? H3O + (aq) + OH– (aq) → 2H2O (l)

In a constant‑pressure calorimeter, 60.0 mL of 0.320 M Ba(OH)2 was added to 60.0 mL of 0.640 M HCl.The reaction caused the temperature of the solution to rise from 24.50 ∘C to 28.86 ∘C. If the solution has the same density and specific heat as water (1.00 g/mLand 4.184J/g⋅°C, respectively), what is ΔH for this reaction (per mole H2O produced)? Assume that the total volume is the sum of the individual volumes. ΔH= _________ kJ/mol H2O

A 25.0 mL portion of dilute HCl (aq) is combined with a 25.0 mL portion of dilute NaOH in a coffee-cup calorimeter. Both solutions are initially at a temperature of 23.3 ºC. The reaction produces enough heat to raise the final temperature of the 50.0 mL of liquid in the calorimeter to 25.3 ºC . What is qrxn in J? Assume the density of the reaction mixture is 1.0 g/mL and the specific heat of the solution is 4.184 J/g· ºC