chem 116 quiz 7 Flashcards
ΔE =
q+w
heat + work
w =
-P Δ V
for the constant volume (calorimeter) reactions, the ΔV=0, so w is also 0, and ΔE,rxn =
q,v
calorimetry definition
the way to measure the heat evolved in a chemical reaction
in calorimetry, we measure
the thermal energy the reaction and the surroundings exchange by observing the change in temperature of the surroundings
for constant pressure reactions, which is a chemical reaction occurring in an open-to-the-atmosphere container, the enthalpy, H, is introduced to describe ? ; H = ?
the thermodynamic quantity
H = E + PV (the sum of its internal energy and the product of its pressure and volume)
ΔH =
q,p
positive ΔH indicates
heat flows into the system as the reaction occurs (endothermic)
negative ΔH indicates
exothermic; reaction gives off heat to its surroundings
how to caibrate the calorimeter
mixing hot and cold water
the acids and bases are about ? times as strong as we are used to
10
safety precautions
no eating, drinking, smoking, chewing; splash-proof goggles, long pants, close-toed shoes
specific heat capacity of water
4.18 J/g*C
units for enthalpy
J/mol or J/kg (?)
units for heat
J
