Answer:
33.21% is the right answer.
Explanation:
0.04720 L * 0.02240 mol / L = 1.0573*10-3
mol Fe+2 = 1.0573* 10-3 mol = 5.2864*10-3
mass of Fe= 5.2864 * 10-3 = 0.29522g
% of Fe in sample = 0.29522 g Fe / 0.8890 g of sample * 100 = 33.21%
Answer:
Option A: 1*10^-5 M HCl has a pH of 5
Explanation:
a) 1.0 * 10^‒5 M HCl
HCl = a strong acid
pH of HCl = -log[H+]
ph of a 10^‒5 M HCl = -log(10^-5) = 5
(b) 1.0 * 10^5 M NaOH
pOH = -log(10^-5) = 5
pH = 14 -5 = 9
(c) A solution containing approximately equal concentrations of hypochlorous acid (HOCl, Ka = 2.9 * 10^‒8) and the dissolved salt of its conjugate base sodium hypochlorite (NaOCl).
pH = pKa + log[NaOCl/HOCl]
Since [NaOCl]/ [HOCl]= 1
pH = pKa +log(1)
pH = pKa
pH = -log(2.9 * 10^-8)
pH = 7.54
(d) A solution containing approximately equal concentrations of potassium hydrogen phthalate (C8H5KO4, Ka = 3.91 * 10^–6) and the dissolved salt of its conjugate base potassium phthalate.
pH = pKa +log[potassium phthalate/C8H5KO4)
Since [potassium phthalate]/[C8H5KO4] = 1
pH = pKa
pH = -log(3.91*10^-6)
pH = 5.41
e) A solution containing approximately equal concentrations of ammonia (Kb = 1.8 * 10^‒5) and the dissolved salt of its conjugate acid ammonium chloride.
pOH = pKb +log[NH4Cl]/[NH3]
Since [NH4Cl]/[NH3] = 1
pOH = pKb
pOH = 4.74
pH = 14-4.74 = 9.26
Answer:
Surface tension
Capillary action
Explanation:
Surface tension is the force acting along the surface of the liquid causing the liquid surface to behave like a stretched elastic skin. Surface tension causes the water drops that fall on a smooth surface to form rounded drops or beads.
If you touch a piece of paper to the drop, water appears to move up into the paper on its own due to capillarity. Capillarity is the tendency of a liquid to rise or fall in a narrow tube.
Answer:
The NaCl concentration will be 0.03 M.
Explanation:
Given data:
Initial volume = V₁ = 56.98 mL (56.98/1000 = 0.05698 L)
Initial concentration = M₁= 0.5894 M
Final volume = V₂= 1.20 L
Final concentration = M₂= ?
Solution:
By diluting the solution volume of solution will increase while number of moles of solute remain the same.
Formula:
Initial concentration × Initial volume = Final concentration × Final volume
M₁V₁ = M₂V₂
M₂ = M₁V₁ / V₂
M₂ = 0.5894 M × 0.05698 L / 1.20 L
M₂ = 0.0336 M /1.20
M₂ = 0.03 M
Probably the type of pot used? Amount of water? Just throwing out options