Question

question 3 (1 point) saved
for a 25.0 % m/v mgcl₂ solution, what is the molarity ? in problem 2 we determined that this is a 2.63 m solution.
first we have to convert moles into equivalents
mgcl₂ → mg⁺² + 2 cl⁻¹
1 mol = 1 equivalents
2 mol 3 eq
(----------)(-----------) = 4 eq/l
5 l 6 mol
a. 250. b. 100.0 c. 2 d. 30.00 e. 6 f. 24
g. 3 h. 36 i. 18.0 j. 1 k. 6.00×10⁻³ l. 3.60×10⁻²
m. 6.00×10⁻³ n. 5 o. 3.0×10⁻² p. 1.80×10⁻²
q. 7.65×10⁻¹⁰ r. 2.63 s. 7.89 t. 5.26 u. 10¹²
v. 10⁹ w. 10⁶ x. 10³ y. 95.21 z. 10

Explanation:

Step1: Analyze the dissociation of \(MgCl_2\)

From \(MgCl_2
ightarrow Mg^{2 +}+2Cl^{-1}\), the total charge change per mole of \(MgCl_2\) is \(2 + 1=3\) (since \(Mg^{2+}\) has a charge of \(+ 2\) and there are \(2\) \(Cl^{-}\) ions each with a charge of \(-1\)). So \(1\) mol \(MgCl_2=3\) equivalents.

Step2: Determine the number of moles

The molarity of the \(MgCl_2\) solution is given as \(2.63\) M. So the number of moles (\(_2\)) is \(2.63\) (option R).

Step3: Calculate equivalents per liter

Using the formula \(\text{Equivalents per liter}=\frac{\text{Moles}\times\text{Equivalents per mole}}{\text{Volume (L)}}\). Assuming a volume of \(1\) L (since molarity is moles per liter), \(\text{Equivalents per liter}=2.63\times3 = 7.89\) (option S).

Answer:

1. G. 3
2. R. 2.63
3. S. 7.89