4.0 mol. 6.02 x 10. 23 atoms. 3. How many moles are in 2.5g of lithium? 2.5 grams Li. 1 mole. = 0.36 mol. 6.9 g. 4. Find the mass of 4.8moles of iron. 4.8 moles.
According to Data,
Mass Number = 65
# of Neutrons = 35
As we know,
Mass Number = # of protons + # of Neutrons
Solving for # of protons,
# of protons = Mass Number - # of Neutrons
Putting values,
# of Protons = 65 -35
# of protons = 30
As,
# of protons is the atomic number, so element with atomic number 30 is Zinc.
The cation derived from it has 28 electrons,
So, Zinc having 30 electron will be left with two extra protons, and each proton has +1 charge.
Result:
Zn²⁺
Answer:
85.5%
Explanation:
To get the experimental value, you need to convert 15.0 grams of Na2SO4 to grams of Na3PO4. You do this with stoichiometry.
Convert grams of Na2SO4 to moles with molar mass. Then convert to moles of Na3PO4 with the mole-to-mole ratio according to the balanced chemical equation. Then convert moles of Na3PO4 to grams with the molar mass.
15.0 g Na2SO4 x (1 mol/142.04 g) x (2 Na3PO4/3Na2SO4) x (163.94 g/1 mol) = 11.7 g Na3PO4
Percent Yield = (actual value/experimental value) x 100
Actual Value = 10.0 g
Experimental Value = 11.7 g
10.0g/11.7 g = 85.5%
Explanation:
The given data is as follows.
Concentration of acid, [HF] = 2 M
Concentration of salt, [NaF] = 0.472 M
Concentration of base, [NaOH] = 1.00 M
= 
So, NaOH being a base will react with the acid that is, HF. And, according to Henderson-Hasselbalch equation we have he following.
pH = ![pK_{a} + log\frac{[salt]}{[acid]}](https://tex.z-dn.net/?f=pK_%7Ba%7D%20%2B%20log%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D)
Also, we known that 
so, 
= 3.1426
Hence, pH = 
pH = 2.5155
Thus, we can conclude that pH of the solution is 2.5155.
