Answer:
3.45 moles Li contains 2.08
×
10
(to the power of)24 atoms
.
Explanation:
The relationship between atoms and moles is:
1 mole atoms
=
6.022
×
10
(to the power of)23
atoms
In order to determine how many atoms occupy a given number of moles, multiply the given moles by
6.022
×
10
(to the power of)23
atoms/mole
.
In the case of 3.45 moles lithium (Li):
3.45
mol Li
×
6.022
×
10
(to the power of)23 atoms Li/
1
mol Li
=
2.08
×
10
(to the power of)24
atoms Li rounded to three
Answer:
thay all are different from each other
Answer : The value of Ka for acetic acid is, 
Explanation :
The chemical formula of acetic acid is,
.
The chemical equilibrium reaction will be:

Given:
pH = 2.96
First we have to calculate the concentration of hydrogen ion.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
![2.96=-\log [H^+]](https://tex.z-dn.net/?f=2.96%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=1.096\times 10^{-3}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D1.096%5Ctimes%2010%5E%7B-3%7DM)
That means,
![[H^+]=[CH_3COO^-]=1.096\times 10^{-3}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D%5BCH_3COO%5E-%5D%3D1.096%5Ctimes%2010%5E%7B-3%7DM)
![[CH_3COOH]=0.0602-(1.096\times 10^{-3})=0.0591M](https://tex.z-dn.net/?f=%5BCH_3COOH%5D%3D0.0602-%281.096%5Ctimes%2010%5E%7B-3%7D%29%3D0.0591M)
The expression for reaction is:
![K_a=\frac{[CH_3COO^-][H^+]}{[CH_3COOH]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BCH_3COO%5E-%5D%5BH%5E%2B%5D%7D%7B%5BCH_3COOH%5D%7D)


Thus, the value of Ka for acetic acid is, 
½H2(g) + ½I2(g) → HI(g) ΔH = +6.2 kcal/mol
or...
½H2(g) + ½I2(g) + 6,2kcal/mole → HI(g)
________
21.0 kcal/mole + C(s) + 2S(s) → CS2(l)
or...
C(s) + 2S(s) → CS2(l) ΔH = +2,1 kcal/mole
_________
ΔH > 0 ----------->>> ENDOTHERMIC REACTIONS
Good electrical conductivity and electronegativities less than 1.7 are the properties and characteristic of Group 2 elements at STP.
<h3>What are the properties of group 2 elements?</h3>
Group 2 elements are metals so they are good conductors of heat and electricity. It has electronegativity values less than 1.7 and very reactive. They form 2+ charge in cationic form and also formed ionic bonds with other negatively charged elements.
So we can conclude that good electrical conductivity and electronegativities less than 1.7 are the properties and characteristic of Group 2 elements at STP.
Learn more about electronegativity here: brainly.com/question/2415812
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