Answer:
394.99g
Explanation:
The number of moles of a substance can be calculated by dividing the number of atoms of such substance by Avagadro's number (6.02 × 10^23)
n = nA ÷ 6.02 × 10^23
The number of atoms of Fp3BZ2 in this question is 2.45E24 formula units i.e. 2.45 × 10^24
n = 2.45 × 10^24 ÷ 6.02 × 10^23
n = 2.45/6.02 × 10^(24-23)
n = 0.407 × 10¹
n = 4.07moles
Using mole = mass/molar mass
Where; molar mass of Fp3Bz2. is 97.05
g/mol.
mass = molar mass × mole
mass = 97.05 × 4.07
mass = 394.99g
4 Hydrogen Atoms should be correct. Because the 4 infront of it signifies the amount of hydrogen. It would also be 4 hydrogen atoms if it were written as H4N3, because the 4 is still around the H (as long as the 4 is under scored)
Zn+2HCl ----> 2ZnCl2 + H2
For 2.50 g of Zn
Mass per mol = 2.50/molar mass of Zn = 2.50/65.38 = 0.0382 g/mol
There are two moles of ZnCl2 and total mass = 2*0.0382*molar mass of ZnCl2 = 2*0.0382*136.286 = 10.42 g
For 2 g of HCl
Mass per mol = 2/2*molar mass of HCl = 2/ (2*36.46) = 0.0274 g/mol
For the two moles of ZnCl2, mass produced = 2*0.0274*136.286 = 7.48 g
It can be noted that 2 g of HCl produced less amount of ZnCl and thus it is the limiting reagent.
I have posted the answetr in this picture.