NEW
Font size
WorksheetsEnergy Level Diagrams
Total questions: 10
Worksheet time: 9mins
Which of the following is true about the formation of bonds between molecules?
Energy is given off when bonds are formed between molecules.
Energy is absorbed by the molecule when bonds are formed.
Energy is neither given off nor absorbed when bonds are formed.
Energy is given off when bonds are broken.
The energy level of molecules will _________ during bond breaking and _________ during bond forming.
decrease, increase
increase, increase
increase, decrease
decrease, decrease
Which of the following is an application of exothermic reactions
cold pack
hot pack
cooking an egg
photosynthesis
When the solids Ba(OH)2 and NH4SCN are mixed, a solution is produced and the temperature drops. Which statement about the energetics of this reaction is correct?
The reaction is endothermic and ΔH is negative
The reaction is endothermic and ΔH is positive
The reaction is exothermic and ΔH is negative
The reaction is exothermic and ΔH is positive
The following equation shows the formation of magnesium oxide from magnesium metal. Which statement is correct for this reaction?
2Mg(s) + O2(g) → 2MgO(s); ΔH = -1204 kJ
1204 kJ of energy are released for every mole of magnesium reacted
602 kJ of energy are absorbed for every mole of magnesium oxide formed
602 kJ of energy are released for every mole of oxygen reacted
1204 kJ of energy are released for every two moles of magnesium oxide formed
For the reaction 2H2(g) + O2(g) → 2H2O(g) the bond enthalpies (in kJ/mol) are
H-H = x, O=O = y, O-H = z
Which calculation will give the value, in kJ/mol, of ΔH for the reaction?
2x + y - 2z
4z - 2x - y
2x + y - 4z
2z - 2x - y
Using the table of average bond energies below the image, the ΔH for the reaction in kJ is.....
+160 kJ
-63 kJ
-160 kJ
-217 kJ
Breaking bonds is a/an _______________ process.
Endothermic
Exothermic
Hydrophilic
Hydrophobic
It takes 631 kJ/mol to break a N=O bond. How much energy is required to make a N=O bond?
No option is correct
402 kJ/mol
1262 kJ/mol
-631 kJ/mol
What is the formula for calculating ΔH of a reaction?
ΔH=H (reactants) + H (products)
ΔH=H (reactants) - H (products)
ΔH=H (products) ÷ H (reactants)
ΔH=H (reactants) x H (products)
