A3B9 represents a molecular formula. The representation of the empirical formula for this compound is AB3. This is so because the empirical formula is the simplest ratio of the atoms present in the molecule. You get AB3 when you divide the subscripts of A3B9, this is 3 and 9, by the greatest common factor, which is 3. 3/3 = 1 and 9/3 = 3, so the subscripts for the empirical formula are 1 and 3, which is what AB3 represents. <span>Answer: AB3.</span>
The HCl added = 1.25 moles
and the moles of Na2HPO4 = 1 mole
Now when acid is added in the given solution of Na2HPO4
One mole of H+ will react with one mole of Na2HPO4 to given one mole of NaH2PO4
Na2HPO4 + H+ ---> NaH2PO4
Now this one mole formed NaH2PO4 will further react with 0.25 moles of H+ left to form 0.25 moles of H3PO4 and 0.75 moles of NaH2PO4 will remain in the solution
So this will result into formation of a buffer of phosphoric acid and NaH2PO4
NaH2PO4 + H+ ---> H3PO4
pKa of H3PO4 = 2.1
so pH = pKa + log [salt] / [acid] = 2.1 + log [0.75 / 0.25] = 2.58
so the pH will be in between 2.1 to 7.2
The distance that jet covered in 10 min is 125 Km
calculation
distance = speed x time
speed=750 km/h
time= 10/60hrs
=750 x10/60=125 Km
Answer:
2Au₂S₃ + 6H₂ → 4Au + 6H₂S
Explanation:
Balancing:
2Au₂S₃ + 6H₂ → 4Au + 6H₂S
Atoms can be the source of both nuclear and chemical energy. Nuclear energy involves the atom's nucleus; chemical energy involves the atom's electrons—subatomic particles that surround the nucleus.
