Change in Enthalpy

A reaction that gives out energy to the surroundings causes the

• temperature to drop

• temperature to rise

• temperature to remain constant

• temperature to vary

Tags

NGSS.HS-PS1-4

A reaction that causes the temperature of the surrounding to drop is

• endothermic

• exothermic

• displacement

• oxidation

Tags

NGSS.HS-PS1-4

Standard conditions are;

• 273 K 1 atm

• 20 ^oC 1 atm

• 25 ^oC 2 atm

• 298 K 1 atm

The enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard conditions. This is the enthalpy of.....

• Combustion

• Formation

• Lattice breaking

• Atomisation

The enthalpy change when 1 mole of a compound is completely burned in excess oxygen forming combustion products in their standard states. This is the enthalpy of ....

• Combustion

• Formation

• Ionisation

• Atomisation

ΔH value in an endothermic reaction is a positive number.

• True
• False

A catalyst works by

• decreasing the temperature

• increasing the temperature

• lowering the activation energy

• increasing the concentration

Tags

NGSS.HS-PS1-4

What type of reaction is shown in the reaction pathway?

• endothermic reaction
• exothermic reaction

Tags

NGSS.HS-PS1-4

If they energy required to break the bonds is greater than the energy given out by making new bonds the reaction is

• Exothermic
• Endothermic
• Neutralisation

Tags

NGSS.HS-PS1-4

What is the activation energy?

• 40 kJ
• 20 kJ
• 100 kJ
• 60 kJ

Tags

NGSS.HS-PS1-4