Bond Enthalpy Y11

ΔH value in an endothermic reaction is a positive number.

• True
• False

Tags

NGSS.HS-PS1-4

What type of reaction is shown in the reaction pathway?

• endothermic reaction
• exothermic reaction

Tags

NGSS.HS-PS1-4

Which statement is true regarding endothermic reactions?

• a) Temperature change is positive and enthalpy change is positive
• b) Temperature change is positive and enthalpy change is negative
• c) Temperature change is negative and enthalpy change is positive
• d) Temperature change is negative and enthalpy change is negative

Tags

NGSS.HS-PS1-4

Endothermic reactions feel

• warm
• cold

Tags

NGSS.HS-PS1-4

Define 'Enthalpy'

• a) Energy stored in the movement of molecules in a substance
• b) The opposite of temperature
• c) The temperature of a molecule
• d) Energy stored in the chemical bonds in a substance

Tags

NGSS.HS-PS1-4

A reaction that gives out energy to the surroundings causes the surroundings ....

• temperature to drop

• temperature to rise

• temperature to remain constant

• temperature to vary

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

Some average bond enthalpies, in kJ/mol, are as follows:
H-H = 436
Cl-Cl = 242
H-Cl = 431
What is the enthalpy change for the decomposition of hydrogen chloride?
2 HCl --> H₂ + Cl₂

• -184 kJ
• + 184 kJ
• - 247 kJ
• + 247 kJ

Tags

NGSS.HS-PS1-4

The enthalpy change for the reaction between hydrochloric acid and sodium hydroxide is −56 kJ/mol. Therefore ...

• the reaction is exothermic and the temperature rises

• the reaction is exothermic and the temperature falls

• the reaction is endothermic and the temperature rises

• the reaction is endothermic and the temperature falls

Tags

NGSS.HS-PS1-4

Which of these diagram correctly represent an endothermic reaction?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-4

In an endothermic reaction in aqueous solution, which of the following is correct?

• temperature increases, sign of enthalpy change is positive

• temperature increases, sign of enthalpy change is negative

• temperature decreases, sign of enthalpy change is positive

• temperature decreases, sign of enthalpy change is negative