Calculation questions
Endothermic and Exothermic
Vocabulary
Hess's Law
Free For All
100
How many Joules are in 146 calories
What is 611 Joules
100

A process that releases heat is called

What is exothermic

100

This type of energy changes during a phase change

What is potential energy

100
If you add 2 or more thermochemical equations to give you a final equation, what does it allow you to do?
What is determine the heat of the reaction directly
100

happed during the phase changes melting, vaporization and sublimation

what is heat get absorbed

200
What is the specific heat of a substance if 1560 calories is required to raise a 312 g sample by 15 degrees Celsius?
What is 0.33 cal/gºC
200
Which process is exothermic the vaporization of water/the freezing of water?
What is the freezing of water
200

This is the change in energy in a chemical reaction

What is enthalpy

200
Cl2(g)+2 HBr(g) -> 2 HCl(g)+Br2(g) (delta)H=
What is (delta)H=-112kJ
200

This occurs when a hot object is placed in contact with a cooler object

What is conduction?

What is heat is transferred from the hot object to the cold object?

300
How much energy does it take to convert 750 grams of ice at -15ºC to liquid water at 40ºC?
What is 399 kJ
300
What kind of equation is the following reaction: CH4 + O2 -> CO2 + H2O + 1725 kcal
What is exothermic
300
A quantity of heat needed to change 1 gram of water by 1 degree Celsius.
What is calorie
300
Find (delta)H: N2H4(l)+H2(g) -> 2NH3(g)
What is (delta)H=-18kJ
300
What is the formula to calculate the amount of heat energy exchanged between the system and its surroundings?
What is q= m c (delta)T
400
2 KCl + 3 O2 -> 2KClO3 Given that the heat of formation of potassium chloride is -436 kJ/mol and the heat of formation of potassium chlorate is -391 kJ/mol, determine the heats of reaction.
What is 90 kJ
400
What is an exothermic reaction?
What is a chemical reaction that releases energy
400

This is the amount of energy needed to start a reaction

What is activation energy

400
Find (delta)H: H2SO4(l) -> SO3(g)+H20(g)
What is (delta)H=72.5kJ
400
If you were to touch a flask in which an endothermic reaction was occurring, the flask would feel _____ before the reaction started.
What is cooler than
500
A certain mass of water was heated with 41,840 Joules, raising its temperature from 22.0ºC to 28.5ºC. Find the mass of water
What is 1538.46 g
500
What happens to the system in an endothermic process?
What is the system gains heat and the surroundings cool down
500
What does it mean if the (delta)H value for a chemical reaction is positive?
What is reactants have less potential energy than products.
500
Find (delta)H: N2H4(l)+CH4O(l) -> CH2O(g)+N2(g)+3H2(g)
What is (delta)H=-46.2kJ
500

What amount of heat will be absorbed according to the following equation when 25.0 g of calcium oxide reacts with excess water?  CaO + H2O + 65.2 kJ à Ca(OH)2

what is 29.1 kJ

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