Calculate the molarity of a 10.0% (by mass) aqueous solution of hydrochloric acid. the density of this solution is 1.01 g/ml. a. 0.277 m b. 2.77 m c. 3.04 m d. 4.33 m e. the density of the solution is needed to solve the problem

[HCl] = 2.77 M   (option b)

Explanation:

A 10% by mass is an information that means, 10 g of solute are contained in 100 g of solution.

Density is mass / volume and it always corresponds to solution.

So solution mass is 100 g. Let's find out solution volume with density

Solution mass / Solution volume = Solution density

100 g / Solution volume = 1.01 g/mL

100 g / 1.01 g/mL = 99 mL

In conclusion our 10 g of HCl are contained in 99 mL of solution

Molarity is mol of solute in 1L of solution

Let's convert the mass to moles (mass / molar mass)

10 g / 36.45 g/mol = 0.274 moles

Let's convert the mL in L

99 mL = 0.099L

Molarity is mol/L → 0.274 mol / 0.099L = 2.77M

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.