Exothermic Reactions

What type of reaction occurs in a hand warmer?

• exothermic

• endothermic

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

What instrument would you use to detect an endothermic or exothermic reaction?

• triple beam balance

• ruler

• thermometer

Tags

NGSS.HS-PS3-4

During a particular chemical reaction it takes 100 Kj of energy to break all the bonds and 150 Kj of energy is released when the new bonds form. Which is true about the overall reaction?

• It is endothermic and absorbs energy.

• It is exothermic and releases 150 Kj

• It is exothermic and releases 50 Kj

• It is endothermic and releases energy.

Tags

NGSS.HS-PS1-4

The bond energy in a S=O bond is a little more than 100 Kj. If the molecule SO₂ is made, how much energy is released during the formation of these bonds?

• About 50

• About 100

• About 200

• About 400

Tags

NGSS.HS-PS1-4

Which of these processes is always exothermic?

• evaporation

• burning

• insulation

• melting

Equal amounts of four different substances (A-D) where added separately to equal amounts of an acid and a thermometer placed in the mixture. For which substance is the reaction the most exothermic?

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

O_2(g) + 2 H_2 (g) → 2 H_2O (g) + Energy

• endothermic

• exothermic

Tags

NGSS.HS-PS1-4

 In an exothermic reaction, heat is ...

• absorbed

• released

Tags

NGSS.HS-PS1-4

Which of the following is a characteristic of an exothermic reaction?

• Heat is absorbed from the surroundings

• Heat is released to the surroundings

• The temperature of the surroundings decreases

• The reaction requires continuous energy input

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

In a laboratory experiment, a student mixes two chemicals and observes a temperature increase. What type of reaction is this likely to be?

• Endothermic

• Exothermic

• Neutralization

• Decomposition

Tags

NGSS.HS-PS1-4