Answer:
2.86mol/L
Explanation:
Given parameters:
Number of moles of MgCl₂ = 7.15moles
Volume of solution = 2.50L
Unknown:
Molarity of the MgCl₂ solution = ?
Solution:
The molarity of a solution is the number of moles of solute found in a given volume.
Molarity = 
Insert the parameters and solve;
Molarity = 
= 2.86mol/L
They will attract each other when brought close but when they touch the glass rod will become a negative charge and will repel each other
Answer:
B. Water will freeze
<em>because</em><em> </em><em>the</em><em> </em><em>latent</em><em> </em><em>heat</em><em> </em><em>of</em><em> </em><em>vapourization</em><em> </em><em>decreases</em><em>.</em>
<span>Answer is: pH of solution of sodium cyanide is 11.3.
Chemical reaction 1: NaCN(aq) → CN</span>⁻(aq)
+ Na⁺<span>(aq).
Chemical reaction 2: CN</span>⁻ +
H₂O(l) ⇄ HCN(aq) + OH⁻<span>(aq).
c(NaCN) = c(CN</span>⁻<span>)
= 0.021 M.
Ka(HCN) = 4.9·10</span>⁻¹⁰<span>.
Kb(CN</span>⁻) = 10⁻¹⁴ ÷
4.9·10⁻¹⁰ = 2.04·10⁻⁵<span>.
Kb = [HCN] · [OH</span>⁻]
/ [CN⁻<span>].
[HCN] · [OH</span>⁻<span>] =
x.
[CN</span>⁻<span>] = 0.021 M - x..
2.04·10</span>⁻⁵<span> = x² / (0.021 M
- x).
Solve quadratic equation: x = [OH</span>⁻<span>] = 0.00198 M.
pOH = -log(0.00198 M) = 2.70.
pH = 14 - 2.70 = 11.3.</span>
In response of what like what’s the full clear question
