The graph above shows the changes in temperature recorded for the 2.00 L H2O surrounding a constant-volume container in which a 1.00 g sample of benzoic acid was combusted. Assume that heat was not absorbed by the container or lost to the surroundings, that the density of H2O is 1.00g/mL, and that the specific heat capacity of H2O is about 4.2J/g⋅°C. Based on this information, estimate how much heat was released from the combustion of the benzoic acid sample.
For an experiment, a 20.0 g piece of Al was placed inside an insulated cup filled with 40.0 g of H2O. The data are given in the table above. Assuming no heat is absorbed by the container or the surroundings, which of the following equations provides the correct mathematical relationship for the transfer of heat q between Al and H2O?
A student dissolves 8.00 g of NH4NO3(s) in 100. g of H2O(l) in a coffee-cup calorimeter. Based on the initial and final temperatures of the mixture in degrees Celsius shown in the diagram above the laboratory setup, what is the calculated ΔT of the water reported to the appropriate number of significant figures?
Particulate models of the evaporation of liquid water and the condensation of water vapor are shown above. Based on these models, which of the following accurately compares the energy changes associated with each of the phase changes?
The table above provides the values for some physical properties of H2S and H2O. Approximately, how many moles of H2S must be condensed to release as much heat as would be released when 1 mole of H2O is condensed?
The heating curve for 1.0 mole of Na, initially at 25.0°C, is shown above at the left. Which of the following best explains the change in heat when 0.50 mole of Na
Na undergoes the transition shown in the diagram above to the right?
The enthalpy change for the reaction represented by the chemical equation shown above is ΔH°=−1236kJ/molrxn. When 2.00mol of NaOCl(aq) reacts completely with an excess of Na2S2O3(aq) and of NaOH(aq)), which of the following enthalpy changes occurs?
The chemical equation shown above represents the thermite reaction. What is the approximate amount of heat released when 108g of Al(s) reacts with excess Fe2O3(s)?
The equation shown above represents an endothermic reaction between CO(g) and C(g). What is the amount of heat absorbed when 1.00mol of CO(g) reacts with an excess C(g) ?