Enthalpy

How do you calculate Enthalpy of a reaction?

• ΔH = ΔH_products - ΔH_reactants

• ΔT = q / mC

• ΔG = ΔH -TΔS

• E = mc²

Specific heat capacity is

• heat energy needed to raise temp by 1C
• heat energy needed to raise temp of 1g of substance by 1C
• heat energy absorb to raise 1g of substance to higher temp
• heat energy need to raise temp for 1g of substance

"Heat change when 1 mole of gaseous atom is formed from its element at standard condition" is the definition for _______.

• standard enthalpy of formation

• standard enthalpy ofhydration

• electron affinity

• standard enthalpy of atomisation

What is standard enthalpy of formation, ΔH_f^o?

• Heat change when 1 mole of gaseous ions is hydrated in water at 25^oC and 1 atm

• Heat change when 1 mole of compound is formed from its elements in their stable state at standard condition of 25^oC and 1 atm

• Heat change when 1 mole of gaseous atom is formed from its elements at 25^oC and 1 atm

• Heat change when 1 mole of electrons is removed from 1 mole of gaseous atoms at ground state at 25^oC and 1 atm

Tags

NGSS.HS-PS1-2

NGSS.HS-PS3-1

Name the type of enthalpy for the following reaction:

Na⁺ (g) --> Na⁺ (aq) ΔH = -364 kJmol^-1

• Standard enthalpy of neutralisation, ΔH_neut^o

• Standard enthalpy of solution, ΔH_soln^o

• Standard enthalpy of hydration, ΔH_hyd^o

• lattice energy, ΔH_lattice^o

Enthalpy change represented by the equation

MgSO₄ (s) ---> Mg²⁺ (aq) + SO₄ ^2- (aq)

is known as_____________.

• ionization energy of magnesium and sulphate

• lattice crystal energy of magnesium sulphate

• enthalpy of solution of magnesium sulphate

• enthalpy of hydration of magnesium sulphate

Tags

NGSS.HS-PS3-1

Define standard enthalpy of combustion.

• Heat released when one mole of substance is burnt completely in excess oxygen.

• Heat absorbed when one mole of substance is burnt completely in excess oxygen under standard conditionj

• Heat released when one mole of substance is burnt completely in excess oxygen under standard condition.

• Heat change when one mole of substance is burnt partially in excess oxygen under standard condition.

Which of the following has a ΔH_f^o value of 0?

• Br₂(g)

• N(g)

• CO(g)

• Ne(g)

Tags

NGSS.HS-PS1-4

What is the type of standard enthalpy of this reaction?

Na(s) ---> Na(g) ΔH = +109 kJmol^-1

• standard enthalpy of formation

• standard enthalpy of combustion

• standard enthalpy of atomisation

• standard enthalpy of hydration

Which of the equation below refers to the standard enthalpy of formation, ΔH_f^o?

• Na(g) ---> Na⁺(g) + e^- ΔH = -364 kJmol^-1

• C₂H₅OH(l) + 3O₂(g) ---> 2CO₂(g) + 3H₂O (l) ΔH = - 1286 kJmol^-1

• 2C(s) + 2H₂(g) ---> C₂H₄ (g) ΔH = - 52.3 kJmol^-1

• Na⁺(g) ---> Na⁺(aq) ΔH = - 364 kJmol^-1

Tags

NGSS.HS-PS1-4