Enthalpy change

The enthalpy of combustion is the enthalpy change

• when one mole of the pure compound is formed from its elements under standard conditions

• when 1 mole of pure substance is completely burned in excess oxygen, under the given temperature and pressure of the reaction

• when 1 mole of H⁺ (aq) ions from acid reacts with 1 mole of OH^- (aq) ions from an alkali to form 1 mole of water under the stated condition of the experiment

• the magnitude of the enthalpy change of a chemical reaction depends only on the difference in the enthalpy content of the products and the reactants, and does not on how the reaction is completed

The enthalpy of formation is the enthalpy change

• when one mole of the pure compound is formed from its elements under standard conditions

• when 1 mole of pure substance is completely burned in excess oxygen, under the given temperature and pressure of the reaction

• when 1 mole of H⁺ (aq) ions from acid reacts with 1 mole of OH^- (aq) ions from an alkali to form 1 mole of water under the stated condition of the experiment

• the magnitude of the enthalpy change of a chemical reaction depends only on the difference in the enthalpy content of the products and the reactants, and does not on how the reaction is completed

The enthalpy of neutralisation is the enthalpy change

• when one mole of the pure compound is formed from its elements under standard conditions

• when 1 mole of pure substance is completely burned in excess oxygen, under the given temperature and pressure of the reaction

• when 1 mole of H⁺ (aq) ions from acid reacts with 1 mole of OH^- (aq) ions from an alkali to form 1 mole of water under the stated condition of the experiment

• the magnitude of the enthalpy change of a chemical reaction depends only on the difference in the enthalpy content of the products and the reactants, and does not on how the reaction is completed

The SI unit of heat and energy is the __________.

• calorie
• heat
• joule
• watt

Tags

NGSS.HS-PS3-4

ΔH value in an endothermic reaction is a positive number.

• True
• False

Tags

NGSS.HS-PS1-4

 For which of these processes is the value of ΔH expected to be positive?
1.  The temperature increases when calcium chloride dissolves in water.
2.  Steam condenses to liquid water
3.  Water boils
4.  Dry ice sublimates

• 4 only
• 1 only
• 3 and 4 only
• 2 and 3 only

Tags

NGSS.HS-PS1-4

What is this?

• Standard enthalpy change of formation,

• Standard enthalpy change of reaction

• Enthalpy change of combustion

• Standard enthalpy change of formation

What is the name of this enthapyl change

• Enthalpy change of formation

• Enthalpy change of combustion

• Enthalpy change of reaction

• Enthalpy change of atomisation

MgCl₂(s) ---> Mg²⁺(g) + 2Cl^-(g)

This equation represents

• Enthalpy of hydration

• Enthalpy of solution

• Lattice enthalpy of dissociation

• Lattice enthalpy of formation

Which of the following equations represents the enthalpy change of combustion?

• 2C₄H₁₀(g) +13O₂(g) → 8CO₂ (g) + 10H₂0(g)

• C₄H₁₀(g) +13/2O₂(g) → 4CO₂ (g) + 5H₂0(g)

• C₄H₁₀ + 9/2O₂ = 4CO (s)+ 5H₂O

• C₄H₁₀ + 5/2O₂ = 4C(s) + 5H₂O(g)

Tags

NGSS.HS-PS1-4