Unit 3 Ppq Flashcards
Ammonia is an example of a weak base. Describe what is meant by the term weak base
A species that accepts H+ in a reversible reaction
What is meant by a buffer solution
A buffer maintains a constant pH upon addition of small amounts of acid or base
Calculation for [H+]
10^-pH
Why can aluminium form compounds that are electron deficient
Al has 3 outer shell electrons so can form 3 covalent bonds giving 6 outer shell electrons which leaves it electron deficient
Why is the enthalpy change of formation of Cl2(g) zero
As the enthalpy of formation of elements in their standard state is 0
Why do transition elements have variable oxidation states
The energies of the d-orbitals are similar
How can colorimetry be used to find the end point of a titration
A colorimeter is set to find a wavelength of frequency of light absorbed only by an ion in the solution
The end point is when there is no absorbance at one frequency
