Endothermic & Exothermic Chemical Reactions

If a reaction is exothermic, which of the following is true?

• heat is taken in/absorbed

• heat is given off/released

Tags

NGSS.HS-PS1-4

Which of the following is true of an endothermic reaction?

• heat is taken in/absorbed

• heat is given off/released

Tags

NGSS.HS-PS1-4

Which type of reaction is photosynthesis?

6 CO₂ + 6 H₂O + sunlight --> C₆H₁₂O₆ + 6 O₂

• Endothermic

• Exothermic

• Neither

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

Which of the following is true in an exothermic reaction?

• heat is released; bond forming process

• heat is absorbed; bond breaking process

• heat is released; bond breaking process

• heat is absorbed; bond forming process

Tags

NGSS.HS-PS1-4

True or false: ΔH for an endothermic reaction is a positive value.

• True

• False

Tags

NGSS.HS-PS1-4

Examine the equation below:

2KI + MgCl₂ + 200 kJ ----> 2KCl + MgI₂

What type of reaction would this be in lab?

• Endothermic; energy is absorbed and is bond breaking

• Exothermic; energy is released and is bond making

• Endothermic; energy is absorbed and is bond making

• Exothermic; energy is released and is bond breaking

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Examine the equation below. Is the reaction endothermic or exothermic, bond making or bond breaking, and why?

NaCl + AgF + 1560 kJ -----> NaF + AgCl

• Exothermic reaction; no energy is shown on the product side so the energy will be released by the reactants to the products to help them make their bonds.

• Exothermic reaction; no energy is shown on the product side so the energy will be released by the reactants to the products to help the products break their bonds.

• Endothermic reaction; energy is a reactant so energy is being released by the reactants to the products to help them break their bonds.

• Endothermic reaction; energy is a reactant so energy is being taken in by the reactants to help them break their bonds.

Tags

NGSS.HS-PS1-4

Examine the following reaction. Is it endothermic or exothermic and how do you know?

MgO + CaS ----> CaO + MgS + 200 kJ

• exothermic; energy is a product and is a bond forming process

• endothermic; energy is a reactant and is a bond breaking process

• exothermic; energy is a product and is a bond breaking process

• endothermic; energy is a reactant and is a bond forming process

If it takes more energy to make bonds than break bonds the reaction is which of the following?

• Exothermic

• Endothermic

Tags

NGSS.HS-PS1-4

If it takes more energy to break bonds than to make bonds the reaction is said to be which of the following?

• Endothermic

• Exotermic

Tags

NGSS.HS-PS1-4