Answer :
A = In
B = 27
C = 73
D = 49
E = 56
F = 54
G = 66
H = 108
I = 32
Explanation :
Atomic number is defined as the number of protons or number of electrons.
Atomic number = number of protons = number of electrons
Mass number is defined as the sum of number of protons and number of neutrons.
Number of neutrons = Mass number - Number of protons
Number of electrons = Number of protons - charge
Element Number of Number of Number of Atomic
symbol protons electrons neutrons mass
Co 27 27 31 58
In 49 49 66 115
Ta 73 73 108 181
Ba²⁺ 56 54 81 137
S²⁻ 16 18 16 32
KOH+ HNO3--> KNO3+ H2O<span>
From this balanced equation, we know that 1 mol
HNO3= 1 mol KOH (keep in mind this because it will be used later).
We also know that 0.100 M KOH aqueous
solution (soln)= 0.100 mol KOH/ 1 L of KOH soln (this one is based on the
definition of molarity).
First, we should find the mole of KOH:
100.0 mL KOH soln* (1 L KOH soln/
1,000 mL KOH soln)* (0.100 mol KOH/ 1L KOH soln)= 1.00*10^(-2) mol KOH.
Now, let's find the volume of HNO3 soln:
1.00*10^(-2) mol KOH* (1 mol HNO3/ 1 mol KOH)* (1 L HNO3 soln/ 0.500 mol HNO3)* (1,000 mL HNO3 soln/ 1 L HNO3 soln)= 20.0 mL HNO3 soln.
The final answer is </span>(2) 20.0 mL.<span>
Also, this problem can also be done by using
dimensional analysis.
Hope this would help~
</span>
Answer:
Approximately .
Explanation:
The gallium here is likely to be produced from a solution using electrolysis. However, the problem did not provide a chemical equation for that process. How many electrons will it take to produce one mole of gallium?
Note the Roman Numeral "" next to . This numeral indicates that the oxidation state of the gallium in this solution is equal to . In other words, each gallium atom is three electrons short from being neutral. It would take three electrons to reduce one of these atoms to its neutral, metallic state in the form of .
As a result, it would take three moles of electrons to deposit one mole of gallium atoms from this gallium solution.
How many electrons are supplied? Start by finding the charge on all the electrons in the unit coulomb. Make sure all values are in their standard units.
.
.
Calculate the number of electrons in moles using the Faraday's constant. This constant gives the size of the charge (in coulombs) on each mole of electrons.
.
It takes three moles of electrons to deposit one mole of gallium atoms . As a result, of electrons would deposit of gallium atoms .