When hydrogen fluoride (HF) is mixed with sodium fluoride (NaF), it forms a solution known as acidulated sodium fluoride, which is commonly used for topical fluoride treatments in dentistry to help prevent tooth decay.
When a strong acid is added to a buffer solution containing NaF and HF, the strong acid will react with the weak base (F-) to form HF. The buffer solution will resist changes in pH by the common ion effect, maintaining the solution's acidity around the initial pH of the buffer. The chemical equation can be written as H+ + F- ↔ HF.
First recognize that NaF is the salt of a strong base (NaOH) and a weak acid (HF), so the pH will be alkaline. Next, look at the hydrolysis of NaF: NaF + H2O ---> NaOH + HF, or looking at it another way.... F^- + H2O ---> HF + OH- and here F^- acts as a base, so we need the Kb for NaF and that will be the inverse of the Ka for HF. The Ka for HF is 6.6x10^-4, so Kb = 1x10^-14/6.6x10^-4 = 1.5x10^-11. Now, Kb = [HF][OH-]/[F-] = (x)(x)/(0.89) = 1.5x10^-11 x^2 = 1.3x10^-11 x = 3.6x10^-6 = [OH-] pOH = -log 3.6x10^-6 = 5.44 pH = 8.6 (note the pH is alkaline, as expected)
The balanced equation for the reaction between sodium metasilicate (Na2SiO3) and hydrofluoric acid (HF) to produce hexafluorosilicic acid (H2SiF6), sodium fluoride (NaF), and water (H2O) is: 3Na2SiO3 + 12HF → 2H2SiF6 + 6NaF + 9H2O
Hydrofluoric acid is a solution of hydrogen and fluoride mixed with water. Its chemical formula is HF. It is a chemical compound and considered a weak acid but can be heavily corrosive.
Hydrogen Fluoride can be changed to a salt by reacting it with a neutralizing agent such as Soda Ash (forming a sodium fluoride salt) or a caustic such as Potassium Hydroxide (to form potassium fluoride). Hydrogen Fluoride (HF) or hydrofluoric acid has unique properties that can present special handling hazards. It should only be handled by people with special training in the properties of HF and the first aid and medical procedures for exposure. Special protective clothing should be worn.
The conjugate acid of NaF is HF (hydrofluoric acid). When NaF accepts a proton, it forms HF.
c. The addition of NaF to an aqueous HF solution will increase the concentration of HF. This is because NaF will react with HF to form NaHF2, which increases the amount of HF present in the solution.
NaF
When a strong acid is added to a buffer solution containing NaF and HF, the strong acid will react with the weak base (F-) to form HF. The buffer solution will resist changes in pH by the common ion effect, maintaining the solution's acidity around the initial pH of the buffer. The chemical equation can be written as H+ + F- ↔ HF.
First recognize that NaF is the salt of a strong base (NaOH) and a weak acid (HF), so the pH will be alkaline. Next, look at the hydrolysis of NaF: NaF + H2O ---> NaOH + HF, or looking at it another way.... F^- + H2O ---> HF + OH- and here F^- acts as a base, so we need the Kb for NaF and that will be the inverse of the Ka for HF. The Ka for HF is 6.6x10^-4, so Kb = 1x10^-14/6.6x10^-4 = 1.5x10^-11. Now, Kb = [HF][OH-]/[F-] = (x)(x)/(0.89) = 1.5x10^-11 x^2 = 1.3x10^-11 x = 3.6x10^-6 = [OH-] pOH = -log 3.6x10^-6 = 5.44 pH = 8.6 (note the pH is alkaline, as expected)
The net ionic equation for HF and NaOH is: HF (aq) + NaOH (aq) -> H2O (l) + NaF (aq).
No it's is HF + (OH)- --> F- + H2O sodium is a spectator ion so it isn't included on each side.
When sodium fluoride reacts with diluted nitric acid, it forms hydrofluoric acid (HF) and sodium nitrate (NaNO3). This reaction is represented by the equation: NaF + HNO3 -> HF + NaNO3. Hydrofluoric acid is a weak acid that can be corrosive and toxic.
HSCN is not a weaker acid than HF. The Ka for HSCN is approximately 1.2x10^-1 and that for HF is approximately 7x10^-4, making HSCN considerably stronger than HF. In fact, a solution of KSCN would have a pH very slightly above 7.0, but close to neutral because it is almost a strong acid. A solution of NaF will have a pH that is basic because it is the salt of a strong base and a weak acid.
NaF is a salt composed of sodium cation (Na+) and fluoride anion (F-). When NaF dissolves in water, it hydrolyzes to form NaOH and HF. The NaOH produced in this reaction is a strong base, resulting in the aqueous solution of NaF being basic.
The balanced equation for the reaction between sodium metasilicate (Na2SiO3) and hydrofluoric acid (HF) to produce hexafluorosilicic acid (H2SiF6), sodium fluoride (NaF), and water (H2O) is: 3Na2SiO3 + 12HF → 2H2SiF6 + 6NaF + 9H2O
Lithium fluoride and hydrogen fluoride, also known as hydrofluoric acid.