Ba(oh)2 is a strong electrolyte. determine the concentration of each of the individual ions in a 0.550 m ba(oh)2 solution.

Answer;

[Ba2+] = 0.550 M  

[OH-] = 1.10 M

Explanation;

Each mol Ba(OH)2 releases 2 mol OH-  

Ba(OH)2 > Ba2+ + 2OH-  

Mole ratio; Ba(OH)2 :Ba2+ = 1 : 1

[Ba2+] = 0.550 M  

Mole ratio; Ba(OH)2: 2OH-  = 1 : 2

= 2 × 0.550 = 1.10

[OH-] = 1.10 M  

This assumes complete ionization (dissociation) of Ba(OH)2.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

let that person have a turn to speak : )