Thermochemical Equations

If ΔH is positive, heat would be shown on the _____ side of the thermochemical equation.

• Reactant

• Product

Tags

NGSS.HS-PS1-4

Calculate ΔH when 2 moles of ethanol (C₂H₅OH) reacts with excess oxygen according to the following thermochemical equation?

• -2733.4 kJ

• -683.35 kJ

• -1366.7 kJ

• -910.67 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

What mass of P₄ must be reacted to produce 5905 kJ of energy?

• 25.43 g

• 563.0 g

• 2.421 g

• 300.0 g

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

The enthalpies of combustion of C(s), H2(g) and C4H9OH(l) (in kJmol^-1) are as follows  
C(s) + O₂(g)   ->  CO₂(g)                                               ∆H=a
H₂(g) + ½O₂(g)   ->   H₂O(l)                                        ∆H=b
C₄H₉OH(l) + 6O₂(g)   ->   4CO₂(g) + 5H₂O(l)  ∆H=c
What is the enthalpy change for the reaction shown below?
  4C(g) + 5H₂(l) + ½O₂(g)   ->   C₄H₉OH(l)

• c – 4a – 5b

• 2a + 10b - c

• 4a + 5b - c

• 2a + 5b + c

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

H₂ + ½ O₂ --> H₂O + 285kJ is an example of a(n)

• Electrical equation

• Heat equation

• Thermochemical equation

Tags

NGSS.HS-PS1-4

• negative

• positive

Tags

NGSS.HS-PS1-4

Consider the information provided below: 2 SO₃(g)→2 SO₂(g) + O₂(g) ∆H^◦_r= +198 kJ/mol at 298 K. Which statement is true for this reaction?

• The reaction will not be spontaneous at any temperature

• The reaction will be spontaneous at all temperatures

• ∆G^◦ _r will be positive at high temperatures.

• ∆G^◦ _r will be negative at high temperatures

A positive ΔH means that:

• In order for the reaction to happen, heat must be input. It is exothermic

• In order for the reaction to happen, heat must be input. It is endothermic.

• When the reaction happens, heat is released. It is exothermic

• When the reaction happens, heat is released. It is endothermic

Tags

NGSS.HS-PS3-1

A positive ΔH means the reaction is:

• complete

• at equilibrium

• exothermic

• endothermic

Tags

NGSS.HS-PS1-4

If the enthalpy ter (ΔH) is negative the reaction is ____.

• Endothermic

• Exothermic

• Neutral

Tags

NGSS.HS-PS1-4