Answer : The volume for 6.0m HCl solution required = 62.5 ml
Solution : Given,
Initial concentration of HCl solution = 6.0m
Final concentration of HCl solution = 1.5m
Final volume of HCl solution = 250 ml
Initial volume of HCl solution = ?
Formula used for dilution is,

where,
= initial concentration
= final concentration
= initial volume
= final volume
Now put all the given values in above formula, we get the initial volume of HCl solution.

= 62.5 ml
Therefore, the volume for 6.0m HCl solution required = 62.5 ml
An atom is most stable when it has eight electrons in its outermost energy level.
Answer:
2.2mL
Explanation:
First, let us analyse what was given from the question:
C1 = 2.09M
V1 =?
C2 = 0.046M
V2 =100mL
Using dilution formula (C1V1 = C2V2), we can calculate the volume of the original solution as follows:
C1V1 = C2V2
2.09 x V1 = 0.046 x 100
Divide both side by the coefficient of V1 ie 2.09, we have:
V1 = (0.046 x 100) / 2.09
V1 = 2.2mL
Answer:
1.71 kJ/mol
Explanation:
The expression for the calculation of the enthalpy change of a process is shown below as:-
Where,
is the enthalpy change
m is the mass
C is the specific heat capacity
is the temperature change
Thus, given that:-
Mass of CaO = 1.045 g
Specific heat = 4.18 J/g°C
So,
Also, 1 J = 0.001 kJ
So,

Also, Molar mass of CaO = 56.0774 g/mol

Thus, Enthalpy change in kJ/mol is:-

Answer:
The answer to your question is Aluminum
Explanation:
Number of clues
1.- If this element has 3 rings in its Bohr model, we are looking for and element located in the third period of the periodic table.
For example Sodium, Magnesium, Aluminum, Silicate, Phosphorus, Sulfur, Chlorine and, Argon.
2.- It makes three bonds to become stable, then we are looking for and element located in the third group like
Boron, Aluminum, Gallium, Indium, etc
Conclusion
The element that has both characteristics is Aluminum