C Flashcards
What does static equilibrium refer to?
A condition where the reaction has not gone to completion, with both products and reactants present.
In static equilibrium, the system is non-reversible.
What does dynamic equilibrium involve?
A state where the rate of the forward reaction equals the rate of the reverse reaction.
In dynamic equilibrium, concentrations of reactants and products remain constant.
In terms of limiting and excess reagents, what does ‘limiting reagent’ mean?
The reactant that is completely consumed in a chemical reaction, limiting the amount of product formed.
The excess reagent is the substance that remains after the reaction.
What is enthalpy (H)?
The internal energy of a system, often used interchangeably with heat in chemistry.
Enthalpy is measured in T/mol of kJ/mol.
What is the standard enthalpy of formation (ΔH°f)?
The change in enthalpy associated with the formation of 1 mol of a substance in its standard state from its constituent elements.
Standard state is defined at 25°C and 100 kPa.
Fill in the blank: The standard enthalpy of formation of an element in its standard state is _______.
0 kJ/mol
What does a positive change in enthalpy (ΔH > 0) indicate?
The process absorbs energy from the surroundings.
This is characteristic of endothermic reactions.
What does a negative change in enthalpy (ΔH < 0) indicate?
The process releases energy into the surroundings.
This is characteristic of exothermic reactions.
What type of reaction is represented by the equation Pb²⁺ + 2Cl⁻ → PbCl₂?
Precipitation reaction.
This reaction forms a solid from aqueous reactants.
True or False: In a metathesis reaction, components of two compounds exchange partners.
True
What is the unit of measurement for enthalpy changes?
kJ/mol
What is the significance of the notation ‘H’ in chemical equations?
It represents enthalpy, or the heat content of a system.
Fill in the blank: A reaction that absorbs energy from the surroundings is termed _______.
endothermic
Fill in the blank: A reaction that releases energy into the surroundings is termed _______.
exothermic
What is the role of the enthalpy change in chemical reactions?
It indicates whether a reaction is endothermic or exothermic.
