Hess's Law and Enthalpy Change Calculations

What is the most important law in this part of chemistry?

• Charles's Law

• Avogadro's Law

• Hess's Law

• Boyle's Law

According to Hess's Law, the enthalpy change accompanying a chemical change is independent of what?

• Route by which the chemical change occurs

• Pressure

• Temperature

• Concentration

What is the enthalpy change if the enthalpy of formation of benzene is -3267 kJ mol-1, enthalpy of combustion of carbon is -394 kJ mol-1, and enthalpy of combustion of hydrogen is -286 kJ mol-1?

• -45 kJ mol-1

• +68 kJ mol-1

• +45 kJ mol-1

• -68 kJ mol-1

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

What is the standard enthalpy change of formation of chloroethane if the enthalpy of formation of ethene is +52.2 kJ mol-1, and the enthalpy of formation of hydrogen chloride is -92.3 kJ mol-1?

• -144.5 kJ mol-1

• +144.5 kJ mol-1

• +68.9 kJ mol-1

• -68.9 kJ mol-1

Tags

NGSS.HS-PS1-4

What is the enthalpy change if the enthalpy of formation of benzene is -3267 kJ mol-1, enthalpy of combustion of carbon is -394 kJ mol-1, and enthalpy of combustion of hydrogen is -286 kJ mol-1?

• -68 kJ mol-1

• +68 kJ mol-1

• -45 kJ mol-1

• +45 kJ mol-1

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

What is the standard enthalpy change of formation of chloroethane if the enthalpy of formation of ethene is +52.2 kJ mol-1, and the enthalpy of formation of hydrogen chloride is -92.3 kJ mol-1?

• -144.5 kJ mol-1

• +68.9 kJ mol-1

• +144.5 kJ mol-1

• -68.9 kJ mol-1

Tags

NGSS.HS-PS1-4

What is the enthalpy change if the enthalpy of formation of benzene is -3267 kJ mol-1, enthalpy of combustion of carbon is -394 kJ mol-1, and enthalpy of combustion of hydrogen is -286 kJ mol-1?

• +45 kJ mol-1

• -45 kJ mol-1

• +68 kJ mol-1

• -68 kJ mol-1

Tags

NGSS.HS-PS1-4

What is the standard enthalpy change of formation of chloroethane if the enthalpy of formation of ethene is +52.2 kJ mol-1, and the enthalpy of formation of hydrogen chloride is -92.3 kJ mol-1?

• +68.9 kJ mol-1

• -68.9 kJ mol-1

• -144.5 kJ mol-1

• +144.5 kJ mol-1

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1