Answer:
Molarity of Na₂CO₃ = 0.25M
% mass = 2.69
Explanation:
Molarity means mole of solute in 1L of solution
Molar mass of solute (Na₂CO₃) = 105,98 g/m
Moles = mass / molar mass → 6.73 g / 105.98 g/m = 0.0635 m
Mol/L = [M]
0.0635 mol/0.250L = 0.25M
Density of solution = Solution mass / Solution volume
1 g/ml = Solution mass / 250 mL → Solution mass is 250g
% mass will be:
In 250 g of solution we have 6.73 g of solute
in 100 g of solution we have (100 . 6.73)/250 = 2.69
The number of valence electrons in 
will be 26.
The atom's outermost inhabited shell is where valence electrons are found. They are significant because they have a major impact on how an atom's chemical characteristics are determined.
The number of valence electron in P in 5 and number of valence electron in Cl is 7. There are one molecule of P and three molecule of Cl in molecule. By adding all valence electrons , the total number of valance electrons will be 26.
The Lewis structure of is shown as:
Therefore, the number of valence electrons in will be 26.
To know more about valence electrons
brainly.com/question/13993867
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<span>1. The value of x if the rate doubles when [A] is doubled is that </span><span>x = 1
</span><span>2. Then if the rate quadruples when [A] is doubled is that x= 2
Since x=1 when the rate doubles, so if it quadruples, it will be times 2.
So the solution to this is 1 times 2= 2
x=2</span>
This question is dealing with the half-life of carbon-14 which can be used to determine the age of a substance according to the following equation:
t = [ln(N/No)/(-ln2)] · t1/2
N = # of carbon-14 atoms presently = 250 atoms
No = # of carbon-14 atoms initially = 1000 atoms
t1/2 = half-life = 5730 years for carbon-14
We can now input all of the information into the formula to find the age of the fossil:
t = [ln (250/1000)/-ln2] x 5730 years
t = 11460 years
The fossil should be found to be roughly 11,460 years old.
