Answer:
How many atoms are in 6.2 moles of aluminum? I mol = 6.02X1023 atoms so 6.2 mol = 6.2x (6.02x1025) = 3.73 x1024 atoms of Aluminum
Answer:
pH = 1.6
Explanation:
- HF + H2O ↔ H3O+ + F-
- 2H2O ↔ H3O+ + OH-
- Ka = ( [ H3O+ ] * [ F- ] ) / [ HF ]
mass balance:
1 M = [ HF ] + [ F- ].........(1)
charge balance:
[ H3O+ ] = [ F- ] + [ OH- ]......[ OH- ] : comes from water, therefore it is negligible.
⇒ [ H3O+ ] = [ F- ]...........(2)
(2) in (1):
1 M = [ HF ] + [ H3O+ ]
⇒ [ HF ] = 1 - [ H3O+ ].........(3)
(2) and (3) in Ka:
⇒ Ka = [ H3O+ ]² / ( 1 - [ H3O+ ] )
∴ Ka = 7.0 E-4.......from literature
⇒ [ H3O+ ]² + 7.0 E-4[ H3O+ ] - 7.0 E-4 = 0
⇒ [ H3O+ ] = 0.0261 M
⇒ pH = 1.6
Answer:
Explanation: Mendeleev arranged the elements on the basis of their atomic mass. Melting and boiling point were used as the physical characteristics in deciding the position of elements. He arranged the elements and wrote the formula of their oxides and hydrides which seemed to possess same chemical formula.
Explanation:
Ion with a 1+ charge. The atom would normally be neutral, since it has the same number of electrons as it does protons; removing an electron leaves one more proton than electron. Since protons are positive and there's one more of them than electrons in the new ion, it has a 1+ charge.
