Bomb Calorimeter 2D: Heat of Combustion Cross-Section

Sample

Sample mass 1.20 g

Water bath mass 2.00 kg

Calorimeter constant C_cal 2.50 kJ/°C

Sealed. Ready to ignite.

Live readings

Water temperature

25.00 °C

ΔT so far

0.00 °C

Heat released Q

0.00 kJ

Total heat capacity

10.87 kJ/°C

Measured ΔH_combustion

— kJ/g

How it works

This is the 2D cross-section companion to the 3D bomb-calorimeter simulator: the same steel "bomb" seals a weighed sample under oxygen inside a known mass of stirred water, drawn here as a flat side-view slice you can pan and zoom instead of orbit. Igniting the sample releases essentially all of its combustion energy as heat, which raises the temperature of the water plus the calorimeter hardware itself:

Heat released:      Q = m_sample × |ΔH_c|
Total heat capacity: C_total = C_cal + m_water × c_water   (c_water = 4.184 kJ/kg·°C)
Temperature rise:    ΔT = Q / C_total
Measured ΔH_c:        ΔH_c = -(C_total × ΔT) / m_sample

Because the bomb is sealed and (essentially) rigid, no work is done on the surroundings, so the heat measured at constant volume equals the internal-energy change of combustion, ΔU_comb ≈ ΔH_comb for these reactions. This is exactly how benzoic acid is burned first to calibrate C_cal, then unknown samples are burned to find their heat of combustion.

Substance — sets the reference heat of combustion used to drive the reaction (benzoic acid ≈ 26.4 kJ/g, glucose ≈ 15.6 kJ/g, ethanol ≈ 29.7 kJ/g, naphthalene ≈ 40.1 kJ/g).
Sample mass / water mass / C_cal — set up the experiment exactly as a real calorimetrist would before ignition.
Ignite — sparks the sample; the water molecules speed up and shift toward red as heat diffuses in, and the thermometer column climbs to the new equilibrium.
The "Measured ΔH_combustion" readout is computed only from C_total and the observed ΔT — exactly as it would be from real calorimeter data — and should land close to the substance's true value once the reading settles.
Drag to pan, scroll/pinch to zoom — inspect the bomb, thermometer or water bath up close; the underlying heat-capacity model keeps running regardless of view.

Cool water molecules Heated water molecules Combustion (inside bomb)

drag to pan · scroll to zoom