Thermochemical Reactions

C+ O₂ --> CO₂ + 60kJ, what is the value for ΔH for the reaction?

• +60

• -60

• there is no way to know

Tags

NGSS.HS-PS1-4

What will ΔH be if there is 1 mole of oxygen?

• -500 kJ

• 500 kJ

• -750 kJ

• -4500 kJ

Tags

NGSS.HS-PS1-4

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

2N₂ + 3H₂ --> 2NH₃ + 46 kJ
How much energy would be produced if only 1 mol of nitrogen was reacted?

• 92 kJ

• 0.143 kJ

• 23 kJ

• 15 kJ

Tags

NGSS.HS-PS3-1

Consider the following reactions:Fe(s) + 1/2 O2(g) --> FeO(s) H= -272.0 kJ2 Fe(s) + 3/2 O2(g) --> Fe2O3(s) H= -825.5 kJDetermine the delta H for the reaction: 2 FeO(s) + 1/2 O2(g) --> Fe2O3

• -281.5 kJ

• -1097.5 kJ

• -1369.5 kJ

• 281.5 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Classify the reaction: NO_{2 (g)}--> NO _(g) + 1/2 O_2(g)

• endothermic

• exothermic

• no reaction

• not applicable

Tags

NGSS.HS-PS1-4

The thermochemical equation for the incomplete combustion of carbon into carbon monoxide is represented as: 2C (s) + O₂(g) --> 2CO(g) Compute for the H of the reaction if the overall process above can occur in two steps whose thermochemical equations are given below: (1) C _(s) + O_2(g) --> CO_2(g) H= -392.5 kJ (2) 2 CO_(g) + O_2(g) --> 2CO_2(g) H= -566.0 kJ

• 172.5 kJ

• 1,353 kJ

• -221.0 kJ

• 959.5 kJ

Tags

NGSS.HS-PS1-4

The enthalpy change for the reaction, ∆H_r , is equal to 

• ∆H₁ + ∆H₂

• ∆H₁ - ∆H₂

• -∆H₁ - ∆H₂

• -∆H₁ + ∆H₂

Tags

NGSS.HS-PS1-4

A reaction is performed in a beaker with a temperature probe recording the temperature changes of the reaction.  If the temperature began at 15.0 degrees Celsius and ended at 27.5 degrees Celsius.  If the reaction is our system, is the system endothermic or exothermic?

• Exothermic

• Endothermic

Tags

NGSS.HS-PS3-4

Solid magnesium dissolves in a hydrochloric acid, releasing hydrogen gas and heat from a solution of magnesium chloride. What is the sign on ΔH for this reaction?

• Negative because it is exothermic

• Negative because it is endothermic

• Positive because it is exothermic

• Positive because it is endothermic

Tags

NGSS.HS-PS1-4