Heat

Heat = energy transfer driven by a temperature difference, always flowing hot → cold. Temperature = average particle kinetic energy — related but not the same thing.
Heat capacity: heat needed to raise a substance's temperature by 1°C. Specific heat = per gram; molar heat capacity = per mole.
q = mcΔT calculates heat from mass, specific heat, and temperature change. Specific heat of water = 4.18 J/(g·K).
Calorimetry measures heat changes; a bomb (constant-volume) calorimeter has ΔV = 0 → w = 0 → ΔE = q_v (heat measured directly equals internal energy change).

Heat capacity: The amount of heat required to raise a substance's temperature by 1°C.
Specific heat capacity: The heat capacity of 1 gram of a substance.
Molar heat capacity: Heat required to raise the temperature of 1 mole of a substance by 1°C.
Calorimetry: The technique used to measure the heat involved in a chemical or physical change.
Bomb calorimeter: A rigid, sealed, constant-volume container built to withstand high pressure, used to measure heat of combustion.

q = m × c × ΔT

Specific heat of water = 4.18 J/(g·K), equivalently J/(g·°C).
Worked example: 250 g water, 20°C → 80°C: q = 250 × 4.18 × 60 = 62,700 J (62.7 kJ).

ΔE = q_v

ΔV = 0 in a rigid bomb calorimeter → w = −PΔV = 0 → ΔE = q + w reduces to ΔE = q_v.
Makes bomb calorimeters ideal for measuring heat of combustion directly, with no P-V work correction needed.

Heat and temperature are NOT the same: temperature is a property a system has at any moment; heat only exists as energy in transit between systems.
c can be expressed per °C or per K — ΔT is numerically identical in both since they're equal-sized temperature-DIFFERENCE units.
Two calorimeter types exist: constant-volume (bomb) and constant-pressure. Bomb calorimetry gives ΔE directly; constant-pressure calorimetry gives ΔH (see Enthalpy).

Don't confuse ΔE = q_v (bomb/constant-volume calorimetry) with ΔH = q_p (constant-pressure calorimetry, covered under Enthalpy) — the two calorimeter types measure different quantities directly.
A large ΔT in °C converts to the same ΔT in K — don't add 273 when converting a temperature DIFFERENCE, only when converting an absolute temperature.

How much heat is required to raise 100 g of water by 10°C?

In a bomb calorimeter, why does q_v equal the entire change in internal energy?

What's the difference between heat capacity and specific heat capacity?

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