Enthalpy and Thermochemistry Test

A chemical reaction that absorbs heat from the surroundings is said to be __________ and has a __________ ΔH at constant pressure.

• endothermic; positive

• endothermic; negative

• exothermic; negative

• exothermic; positive

H₂ + Cl₂ --> 2 HCl + 1845 kJ
Is this reaction endothermic or exothermic?

• Endothermic 

• Exothermic

Tags

NGSS.HS-PS1-4

H₂ + 2 C + N₂ + 270.3 kJ --> 2 HCN
Is this reaction endothermic or exothermic?

• Endothermic 

• Exothermic

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

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 type of reaction is this?

• Exothermic

• Endothermic

• Kinetic

• Potential

Tags

NGSS.HS-PS1-4

• The total pressure of the system

• The volume of the system

• The heat content of the system at constant pressure

• The total mass of the system

Tags

NGSS.HS-PS3-4

Calculate the enthalpy of the following reaction:
Ca(OH)₂ -> CaO + H₂O
ΔHf in kJ/mol:  
      Ca(OH)₂  -983.2
        CaO         -634.9
        H₂O         -285.5

• 62.8 kJ

• -62.8 kJ

• -1840.6

• 1840.6

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

In an endothermic reaction, the sum of the heats of formation of the products are____than the sum of the heats of formation of the reactants. Hint: is ΔH + or -? This about how you calculate ΔH

• less than

• greater than

• equal to

Tags

NGSS.HS-PS3-1

When heat flows from system to the surroundings that is an example of an ________________ process.

• exothermic

• endothermic

Tags

NGSS.HS-PS3-4

What device is used to measure the amount of heat involved in a chemical reaction or physical process?

• barometer

• calorimeter

• thermometer

Tags

NGSS.HS-PS3-4