Final

Which statement best describes a chemical reaction in which energy is released?

• It is exothermic and has a negative ΔH

• It is exothermic and has a positive ΔH

• It is endothermic and has a negative ΔH

• It is endothermic and has a positive ΔH

Tags

NGSS.HS-PS1-4

Which term refers to the difference between the PE of the products and the PE of the reactants of a chemical change?

• heat of fusion

• heat of reaction

• heat of vaporization

• activation energy

Tags

NGSS.HS-PS1-4

Which statement correctly describes an endothermic chemical reaction?

• The products have higher potential energy than the reactants, and the ΔH is negative.

• The products have lower potential energy than the reactants, and the ΔH is negative.

• The products have higher potential energy than the reactants, and the ΔH is positive.

• The products have lower potential energy than the reactants, and the ΔH is positive.

Tags

NGSS.HS-PS1-4

Which equation represents an exothermic reaction at 298K?

• 
• 
• 
• 

Which reaction releases the greatest amount of energy per twice the amount of product?

• 
• 
• 
• 

Based on the reaction, what is the approximate ΔH for the formation of half the amount of H₂O(l)?

• −571.6 kJ

• +571.6 kJ

• −285.8 kJ

• +285.8 kJ

When lithium bromide crystals dissolve in water, the temperature of the water increases. What does this temperature change indicate about the dissolving of lithium bromide?

• It is an endothermic reaction because it absorbs heat.

• It is an endothermic reaction because it releases heat.

• It is an exothermic reaction because it absorbs heat.

• It is an exothermic reaction because it releases heat.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Given the balanced equation, which statement is true about this reaction?

• It is exothermic and ΔH equals -91.98 kJ.

• It is exothermic and ΔH equals +91.98 kJ.

• It is endothermic and ΔH equals -91.98 kJ.

• It is endothermic and ΔH equals +91.98 kJ.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

Given the PE diagram and equation representing the reaction between A and D, according to Table I, substance G could be:

• HI (g)

• H₂O (g)

• CO₂ (g)

• C₂H₆ (g)

What is the mass number of this atom?

• 1
• 3
• 4
• 7

Tags

NGSS.MS-PS1-1