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Pregunta 1
Pregunta
Is an exothermic reaction, is heat given out to the surroundings or taken in heat to the surroundings?
Respuesta
-
given out
-
taken in
Pregunta 2
Pregunta
What symbol is used to show an endothermic reaction?
Respuesta
-
+
-
-
Pregunta 3
Pregunta
Do reactants have more or less chemical energy than products in an exothermic reaction?
Respuesta
-
more
-
less
Pregunta 4
Pregunta
Enthalpy change is the heat change at a constant temperature
Respuesta
- True
- False
Pregunta 5
Pregunta
in enthalpy changes why are standards used?
Respuesta
-
so it doesnt affect the amount of energy of the reation taken which can affect the temp
-
so it doesnt affect the amount of energy of the reation lost which can affect the temp
-
the standard enthaply change measured depends on the reaction not on the conditions
-
so it doesnt affect the amount of energy of the reation created which can affect the temp
Pregunta 6
Pregunta
What are calorimeters designed for?
Respuesta
-
to contain reactions where all the heat produced can be exchanged with the surroundings in a measurable and accurate way
-
to contain reactions where all the energy produced can be lost to the surroundings in a measurable and accurate way
-
to start reactions, providing energy which can be exchanged with the surroundings in a measurable and accurate way
Pregunta 7
Pregunta
What is the equation for heat produced?
Respuesta
-
Heat produced= mass x specific heat capacity of water x temp rise
-
Heat produced= mass x specific heat capacity of water /temp rise
-
Heat produced= mass / specific heat capacity of water x temp rise
Pregunta 8
Pregunta
How do you convert J to KJ?
Respuesta
-
/ 1000
-
x 1000
-
/ 10000
Pregunta 9
Pregunta
what are errors in calorimetry?
Respuesta
-
heat loss to the surroundings, by the apparatus, to the solid reactant
-
the concentration/ volume of the measurement
-
incomplete reaction
-
impure reactants
-
timings
-
inaccurate stirring
Pregunta 10
Pregunta
How do you work out percentage error?
Respuesta
-
(difference between my value and true value/ true value) x 100
-
(difference between my value and true value/ true value) x 1000
-
( true value/ difference between my value and true value) x 100
Pregunta 11
Pregunta
How do you convert q to ^_H?
Respuesta
-
^_= q / no. moles
-
^_= no. moles / q
-
^_= q x no.moles
Pregunta 12
Pregunta
How do you convert q to ^_H?
Respuesta
-
^_= q / no. moles
-
^_= no. moles / q
-
^_= q x no.moles
Pregunta 13
Pregunta
What is the definition of standard enthalpy change?
Respuesta
-
when 1 mole of compound is formed from its constituent elements under standard conditions with all substances in their standard states
-
normal states, stable under standard conditions
-
heat change at a constant pressure
Pregunta 14
Pregunta
sodium hydroxide reacts with HCL and the container becomes really quite warm- what kind of reaction is this?
Respuesta
-
endothermic
-
exothermic
Pregunta 15
Pregunta
What is another name for the conservation of energy?
Respuesta
-
Hess' Law
-
Boyle's Law
-
Heis' Law
Pregunta 16
Pregunta
what kind of working out would you have to use to work out ^_H implying Hess' law
Respuesta
-
enthalpy cycles
-
mechanisms
-
equations
Pregunta 17
Pregunta
In bond enthalpies bonds broken is an exothermic reaction
Respuesta
- True
- False
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