If the pk values for phosphoric acid are 2.15, 6.82 and 12.38, would predominate at ph 5 while would predominate at ph 10.

Phosphoric acid have three protons which is ionized in different . Thats why it is called triprotic acid. The protonisation of phosphoric acid in different can be shown as-→. This is the first ionization. The second and third ionizations are shown as-→+ and →   + P

=5 is near to first equivalence point where = ( + =(2.15+6.82)=4.6. At this , will be present.

At =10, which is near to second equivalence point= (6.82+12.38)=9.7. At  =10, will be present.

fire could start, buildings collapsing, and ash falling from the sky.

explanation:

this is because the buildings or plants could catch on fire and the buildings would most likely collapse. lastly ash would fall because all the burning would cause ash to fall from the sky.

hope this .

- lead + phosphoric acid = hydrogen + lead(ii) phosphate