mc^t Flashcards
____ in chemical reactions releases energy
bond formation
T or F
bond making is an exothermic process
T
examples with heat transffering
when energy goes from the skin to ice
In a cumbustion reaction, the energy released as the products form is
a. less than the energy required to break apart the reactants
b. more than the energy required to break
c. equal
b
All of the following statements are true about enthalpy except
a. enghalpy is represented by H
b. There is usually a huge difference between enthalpy and energy
c. under constant pressure, the enthalpy change for a reaction is equal to the amount of heat absorbed or released
d. the enthalpy of a substance depends on its temperature, state and composition
b
The enthalpy change for a reaction is determined by
a. subtracting the enthalpy of the products from the enthalpy of the reactants
b. subtracting the enthalpy of the reactants from the enthalpy of the products
b
the standard state of an element is defined as
a. the mass of the element at 25C
b. the most stable form of the element under standard conditions
a. the state of matter at room temp
b
standard conditions
1 atm 25C
the amount of heat required to raise the temperature of an object by 1C is called the
heat capacity
In a calorimeter, the heat lost in a reaction is ___ the heat gained by the water
equal to
kinetic energy theory
heat results from the movement and vibration of particles can be infectious
what has one of the highest specific heats?
water
foods react with ___ in a lab to determine their energy values
oxygen
the amount of heat is detected by measuring a ___ change
temperature
the amount of heat needed to raise an object’s temperature depends on its
heat capacity
every substance has a ___, which tells you how much heat is necessary to raise the temperature of 1g of the substance by 1C
specific heat
what kind of conditions affect deltaH
pressure, temperature, physical state
the symbol deltaH represents?
change in enthalpy
experimental error
(your value-theoretical)/theoretical
x100
must be absolute value
what assumption is made about the mass of water?
no mass from whatever is dissolved in there
why do we extrapolate?
the metals do not react in the same instant (gradual increase).
To calculate deltaH we theoretically estimate the Tf as if it is an instantaneous rxn by extrapolating.
why ignore the heat capacity of the metals?
its very small
gravimetric analysis
analysis using mass
the one where you read the miniscus wrong
parallax error
