Chemistry: Thermochemistry Review 2024/25

What is thermochemistry?

• The study of acids and bases

• The study of energy changes in chemical reactions and changes of state

• The study of atomic structure

• The study of matter at low temperatures

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-5

Which direction does heat flow naturally?

• From cooler objects to warmer objects

• From warmer objects to cooler objects

• In a random direction

• It does not flow without external force

Tags

NGSS.HS-PS3-4

What symbol represents Change in Enthalpy in a chemical equation?

• q

• ΔH

• ΔT

• Cp

An endothermic process will have a ____ ΔH.

• positive

• negative

• neutral

• zero

An exothermic reaction releases heat because:

• It absorbs energy from the surroundings

• More energy is released when new bonds form than it takes to break the initial bonds

• It stores energy in chemical bonds

• It requires energy to proceed

Tags

NGSS.HS-PS1-4

Which of the following is an example of an exothermic reaction?

• Photosynthesis

• Melting ice

• Burning a match

• Boiling water

Tags

NGSS.HS-PS1-4

What is the unit of heat energy in the International System of Units (SI)?

• Calorie

• Kelvin

• Gram

• Joule

Tags

NGSS.HS-PS3-4

The specific heat of water is high because:

• It changes temperature quickly

• It takes a lot of energy to change its temperature

• It is an excellent conductor of heat

• Its molecules are arranged randomly

The amount of energy (q) required to change solid ice to liquid water is _______the amount needed to change liquid water to water vapor

• Less than

• Greater than

• Equal to

• None of the above

Tags

NGSS.MS-PS1-4

The specific heat (at constant pressure) is represented by which of the following symbols?

• ΔH

• q

• Cp

• m