Answer:
6.02×10²³ particles / 1 mol
Explanation:
In this question the choices are missed.
For determine the particles of Na, in 0.25 moles we should know that the mole referrs to the Avogadro's number.
1 mol of anything contains 6.02×10²³ entities, that's why we should apply this conversion factor to find the final answer:
0.25 mol . 6.02×10²³ particles / 1 mol = 1.50×10²³ particles
In conclussion: 1.50×10²³ particles of Na are contained in 0.25 moles of Na
Answer:
The correct approach is "-2.67 kJ/mole". A further solution is described below.
Explanation:
The given values are:
No. of moles,
= 5.60 mol
Substance releases,
ΔH = 14.9 kJ
Now,
The ΔH in terms of kJ/mol will be:
= 
On putting the given values of ΔH, we get
= 
= 
KCO₂
K₂C₂O₄
Explanation:
Given parameters:
Percent composition:
K = 47%
C = 14.5%
O = 38.5%
Molar mass of compound = 166.22g/mol
Unknown:
Empirical formula of compound = ?
Molecular formula of compound = ?
Solution:
The empirical formula of a compound is its simplest formula. Here is how to solve for it:
K C O
Percent
composition 47 14.5 38.5
Molar mass 39 12 16
Number
of moles 47/39 14.5/12 38.5/16
moles 1.205 1.208 2.4
Dividing
by smallest 1.205/1.205 1.208/1.205 2.4/1.205
1 1 2
Empirical formula KCO₂
Molecular formula
This is the actual combination of the atoms:
Molecular formula = ( empirical formula of KCO₂)ₙ
Molar mass of empirical formula = 39 + 12 + 2(16) = 83g/mol
n factor = 
n factor =
= 2
Molecular formula of compound = ( KCO₂)₂ = K₂C₂O₄
Learn more:
Empirical formula brainly.com/question/2790794
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Answer: a) 
b) 
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
a) Mass of Ba= 66.06 g
Mass of Cl = 34.0 g
Step 1 : convert given masses into moles.
Moles of Ba =
Moles of Cl = \frac{\text{ given mass of Cl}}{\text{ molar mass of Cl}}= \frac{34g}{35.5g/mole}=0.96moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Ba =
For O =
The ratio of Ba: Cl= 1:2
Hence the empirical formula is 
b) Mass of Bi= 80.38 g
Mass of O= 18.46 g
Mass of H = 1.16 g
Step 1 : convert given masses into moles.
Moles of Bi =
Moles of O=
Moles of H=
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Bi=
For O =
For H=
The ratio of Bi: O: H= 1:3: 3
Hence the empirical formula is 
I think its A but im not completely sure.