13 Answered Questions for the topic Thermochemistry
Enthalpy of reaction for the combustion: C(s) + O2(g) ⟶ CO2(g) ΔH1 = -395.5 kJ CO(g) + O2(g) ⟶ CO2(g) ΔH2 = -285.0 kJ Using these date,... more
URGENT!!! What can the chemist report for the specific heat capacity of the substance?
A chemist carefully measures the amount of heat needed to raise the temperature of a 697.0g sample of a pure substance from 59.9°C to 67.2°C. The experiment shows that 21.kJ of heat are needed.... more
When 125 mL of 0.220 M NaCl(aq) and 125 mL of 0.220 M AgNO3(aq), both at 21.6°C, are mixed in a coffee cup calorimeter, the temperature of the mixture increases to 24.3°C as solid AgCl... more
2 NH3 → N2 + 3 H2 ΔHrxn = 92.2 kJ/mol How much energy, in kJ, is required to decompose 83.5 grams of Ammonia (NH3)?
A mixture of gaseous reactants is put into a cylinder, where a chemical reaction turns them into gaseous products. The cylinder has a piston that moves in or out, as necessary, to keep a constant... more
Bomb Calorimeter Question
When 6.10 g of urea, (NH2 )2 CO(s) , burns to produce CO2(g) , N2(g) , and H2O(l) ,67.8 kJ of heat energy are released in a bomb calorimeter. What is the energy released in the burning of one mole... more
Hess's Law, enthalpy,entropy,Gibbs free energy change Problem.
For the following unbalanaced reaction at 25°CPbCO3(s)-->PbO(s)+CO2(g)Calculate the standard enthalpy change, change in H° for the reactionCcalculate the standard entropy change, change in S°... more
What is the relation between Molar enthalpy and Change in enthalpy? How do we use them together?
If I calculate Q=mc(delta t) as Q= (54.25 g)(4.19 J/g C)( 6 C) and get 1363.845 J. How do I convert this into change in enthalpy and molar enthalpy? This was done for a Calorimetry... more
A coffee cup has a heat capacity of 62.6J∘C. If the coffee cup's temperature increases by 1.20∘C, how much heat has it absorbed?
Round your answer to the nearest tenth.
An unknown metal absorbs 23.8J of heat, and its temperature increases by 15.4∘C. What is the heat capacity of the metal?
Round your answer to two decimal places.
Calculating Work in Chemistry
I cannot understand these math concepts, and it would be great if someone could help me understand them!A piston containing 1.5 L of gas at 1.00 atm is compressed to 1.25 L. Calculate the value for... more
Thermochemistry: Heating water with Methane
I'm stuck on this one How many grams of methane must be combusted to heat 1.00 kg of water from 25.0 °C to 90 °C, assuming H2O(l) is the product of the reaction and no heat is lost to the... more