Answer:
0.192 mol.
Explanation:
- To calculate the no. of moles of a substance (n), we use the relation:
<em>n = mass / molar mass.</em>
mass of AsH₃ = 15.0 g.
molar mass of AsH₃ = 77.95 g/mol.
∴ The number of moles in 15.0 g AsH₃ = mass / molar mass = (15.0 g) / (77.95 g/mol) = 0.192 mol.
<span>13.7 g
The balanced formula is:
Pb(ClO3)2(aq)+2NaI(aq) ==> PbI2(s) + 2NaClO3(aq)
The number of moles of NaI we have is the volume of fluid multiplied by the molarity so
0.350 * 0.170 = 0.0595 moles
Since the NaI is the limiting reactant, for every two moles used, we'll produce 1 mole of precipitate. So
0.0595 mole / 2 = 0.02975 mole
Now we need to calculate the molar mass of PbI2. Looking up the atomic weights
Atomic weight Lead = 207.2
Atomic weight iodine = 126.90447
Molar mass PbI2 = 207.2 + 2 * 126.90447 = 461.00894 g/mol
Now multiply the molar mass by the number of moles we have.
461.00894 g/mol * 0.02975 mol = 13.71501597 g
Rounded to 3 significant figures, the answer is 13.7 g</span>
Aluminium nitrate is acidic as its made by a weak base with a relatively stronger acid.
Hope that helps ;)
This tells us that in a single molecule of ammonia, there is one nitrogen atom, and three hydrogen atoms.