AP Chemistry Thermochemistry Bond Enthalpies

Covalent bonds are between...

• Metal and Non-metal

• Non-metal and Non-metal

• Metal and Metal

How are covalent bonds formed?

• Sharing of electrons

• Transfer of electrons

Two or more atoms held together by a chemical bond is called what?

• A molecule

• A molecure

Tags

NGSS.MS-PS1-1

Why do elements bond?

• To be friends

• To create a new element

• To become stable

Tags

NGSS.HS-PS1-1

The bond energy to break a C-H bond is about 400 Kj. How much energy will it take to break all the bonds in methane (CH₄)?

• About 800

• About 1600

• About 3000

• Way more than 3000

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

What is the bond enthalpy of a chemical bond an indication of?

• The volume change during the reaction

• The pressure required to break the bond

• The color change when the bond breaks

• The energy required to break the bond in one mole of gaseous molecules

Tags

NGSS.HS-PS1-4

For an exothermic reaction, how do the enthalpies of reactants and products compare?

• The enthalpy of the reactants is the same as the enthalpy of the products

• The enthalpy of the reactants is lower than the enthalpy of the products

• The enthalpy of the reactants is higher than the enthalpy of the products

• The enthalpy of the reactants and products cannot be determined

Tags

NGSS.HS-PS1-4

• The reaction is at equilibrium

• The reaction is endothermic

• The reaction is exothermic

• The reaction does not proceed

Why do elements bond?

• To be friends

• To create a new element

• To become stable

• To get bigger

Tags

NGSS.HS-PS1-3