Chemical Equations
Heat transfer equation
Fuel
Thermochemistry (endo/exo)
Bond Enthalpy Calculations
100
Type of chemical reaction? Mg(OH)2 → Mg + 2OH
Decomposition
100
What does the variable 'm' represent in the heat transfer equation? Which units are used?
Mass and grams (g)
100
Name at least 2 greenhouse gases
water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), etc.
100
Define an endothermic reaction
A reaction that absorbs heat energy
100
Is the calculation for bond enthalpy
a. enthalpy = bond enthalpy reactants - bond enthalpy products
b. enthalpy = bond enthalpy products - bond enthalpy reactants
a. enthalpy = bond enthalpy reactants - bond enthalpy products
Enthalpy = BER - BEP
Enthalpy = Make - Break
200
What are the 6 'types of chemical reactions'
Synthesis, decomposition, single replacement, double replacement, combustion, neutralization
200
What is the specific heat capacity (c) of water? (+10 pts for units)
4.18 J/gºC
200
Predict the products of this reaction
CH4 + O2 →
CH4 + O2 → H2O + CO2
200
Are combustion reactions endothermic or exothermic?
Exothermic
200
Draw this organic compound: C4H8
300
Write the type of reaction and predict the products of this reaction : NaCl + Mg →
Single replacement
NaCl + Mg → MgCl2 + Na
300
If a 500 g piece of copper (c=0.39J/g°C) experiences a temperature change of 30°C, what is the heat transfer (Q)?
5850 J
300
Name the 3 major types of fossil fuels
Coal, oil and natural gas
300
Is water evaporating endothermic or exothermic?
Endothermic: energy is being absorbed by the water
300
Calculate the bond enthalpy of this reaction
ΔH = Make - Break
= 6 494 - 8 528 = -2 034 kJ/mol
400
Balance this chemical equation
Zn + HCl → ZnCl2 + H2
Zn + 2HCl → ZnCl2 + H2
400
What is the device that is used in chemistry to insulate a chemical reaction called?
Calorimeter
400
How many carbon to hydrogen bonds are there in Butane (C4H10)?
10 C-H bonds
400
Draw the potential energy diagram (graph) for an exothermic reaction, label Enthalpy (ΔH) and Activation energy (Ea)
400
Calculate the bond enthalpy for the reaction.
Is the reaction endothermic or exothermic?
ΔH = Make - Break
= 678 - 862 = -184 kJ/mol
Exothermic
500
Balance this chemical equation
Fe + H2O → Fe3O4 + H2
3Fe + 4H2O → Fe3O4 + 4H2
500
If 300 J of heat is added to a 250 g piece of aluminum with a temperature change of 20°C, what is the specific heat (c) of aluminum?
0.06 J/gºC
500
Name the chemical compound found in the majority of automobile fuel (not gasoline)
Octane
500
Is photosynthesis endothermic or exothermic? Write out the chemical equation for photosynthesis and include '+Energy' on the correct side of the equation.
Endothermic:
H2O + CO2 + Energy → C6H12O6 + O2
500
Calculate the enthalpy of combustion of ethane (C₂H₆) using average bond enthalpies
1. write combustion equation
C₂H₆ + O₂ → CO₂ + H₂O
2. Balance
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
3. Draw
4. Calculate:
4 573 - 5 994 = -1 421 kJ/mol