One can tell by looking at the titration curve of an acid and base whether the acid used is a strong acid or a weak acid. For a titration of a strong acid and a strong base, the pH at the equivalence point will be neutral, that is, pH 7. If the titration involves a weak acid and a strong base, the pH at the equivalence point will not be neutral, the solution will be basic at the equivalence point.
(20/23) times 100 is 87%
now the answer asks for percentage ERROR
100-87 =13
so answer is C
To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance. You need to pipet 0 mL of the diluted solution to have 0.00 mg of iron.
In spectrophotometry, to plot the calibration curve, you need to prepare solutions with known concentrations and measure their absorbance.
We have a standard iron solution with a concentration of 0.2500g/L of pure iron (C₁). We pipet 25.00mL (V₁) of this standard iron solution into a 500mL (V₂) volumetric flask and dilute up to the mark with distilled water.
We can calculate the concentration of the diluted solution (C₂) using the dilution rule.
Then, if we wanted to prepare the blank, that is, the solution that contains the same matrix but not the analyte, and whose concentration in iron is 0.00 mg/L, we wouldn't pipet any of the diluted solution.
To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance. You need to pipet 0 mL of the diluted solution to have 0.00 mg of iron.
Learn more: brainly.com/question/24195565
Answer:
0.9 mole of Fe(OH)3.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
Fe(NO3)3 + 3NaOH —> Fe(OH)3 + 3NaNO3
Now, we can determine the moles of iron (III) hydroxide formed from the reaction as follow:
From the balanced equation above,
3 moles of NaOH reacted to produce 1 mole of Fe(OH)3.
Therefore, 2.7 moles of NaOH will react to produce = 2.7/3 = 0.9 mole of Fe(OH)3.
Therefore, 0.9 mole of Fe(OH)3 is produced from the reaction.
Answer:
- <u>2.59 × 10⁻⁷ m = 259 nm</u>
Explanation:
You need to calculate the wavelength of a photon with an energy equal to 463 kJ/mol, which is the energy to break an oxygen-hydrogen atom.
The energy of a photon and its wavelength are related by the Planck - Einstein equation:
Where:
- h = Planck constant (6.626 × 10⁻³⁴ J . s) and
- ν = frequency of the photon.
And:
Where:
- c = speed of light (3.00 × 10⁸ m/s in vacuum)
- λ = wavelength of the photon
Thus, you can derive:
Solve for λ:
Before substituting the values, convert the energy, 463 kJ/ mol, to J/bond
- 463 kJ/ mol × 1,000 J/kJ × 1 mol / 6.022 × 10 ²³ atom × 1 bond / atom
= 7.69×10²³ J / bond
Substitute the values and use the energy of one bond:
- λ = 6.626 × 10⁻³⁴ J . s × 3.00 × 10⁸ m/s / 7.69×10²³ J = 2.59 × 10⁻⁷ m
The wavelength of light is usually shown in nanometers:
- 2.59 × 10⁻⁷ m × 10⁹ nm / m = 259 nm ← answer
