The correct answer should be Letter B
+2, because Beryllium is in the Group II of the periodic table.
Hope this helps!
Answer:
"
" is the right answer.
Explanation:
Given:
Partial pressure of 
,
= 0.20 atm
Partial pressure of 
,
= 0.15 atm
at 
As we know,
⇒ 
By putting the values, we get
Given:
Concentration of Fluoride ions = 0.100 M
Concentration of Hydrogen Fluoride = 0.126 M
Asked: Concentration of fluoride ions after the addition of 5ml of 0.0100 M HCl to 25 mL of the solution
Assume: 50:50 ratio of fluoride ions and HF
12.5ml*0.1mol/L *1L/1000mL + 12.5*0.126mol/L * 1L/1000mL = 2.825x10^-3 moles F-
5ml * 0.01 mol/L *1L/1000mL = 5x10^-5 moles
Assume: Volume additive
Final concentration = 2.825x10^-3 + 5x10^-5 moles/ 30 ml * 1000ml/L =0.0958 M
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