Cr{3+} + 3 NaF → CrF3 +
3 Na{+} <span>
First calculate the total mols of NaF.
(0.063 L) x (1.50 mol/L NaF) = 0.0945 mol NaF total </span>
Using stoichiometric
ratio:
<span>0.0945 mol NaF * (1 mol Cr3+ / 3 mol NaF) * (51.9961 g Cr3+/mol) =
1.6379 g Cr3+</span>
According to the octet rule, atoms tend to gain, lose, or share electrons until they are surrounded by__8__ valence electrons.
The model would look something like the image below.
There would be a <em>central nucleus</em> containing <em>20 protons</em> and <em>20 neutrons</em>.
Surrounding the nucleus would be four concentric rings (energy levels) containing <em>20 electron</em>s.
Going out from the nucleus, the number of electrons in each ring would
be <em>2, 8, 8, 2</em>.
Number of moles = 5 x 10^24 / 6.02 x 10^23 = 8.305 moles. Volume= moles x 22.4 = 186.032 liters. Hope this helps!
Answer:
8.0 moles
Explanation:
Since the acid is monoprotic, 1 mole of the acid will be required to stochiometrically react with 1 mole of NaOH.
Using the formula: 
Concentration of acid = ?
Volume of acid = 10 mL
Concentration of base = 1.0 M
Volume of base = 40 mL
mole of acid = 1
mole of base = 1
Substitute into the equation:

Concentration of acid = 40/10 = 4.0 M
To determine the number of moles of acid present in 2.0 liters of the unknown solution:
Number of moles = Molarity x volume
molarity = 4.0 M
Volume = 2.0 Liters
Hence,
Number of moles = 4.0 x 2.0 = 8 moles