2.5 * 10^4 gallons to mL

The Ka for formic acid (HCO2H) is 1.8 × 10-4. What is the pH of a 0.35 M aqueous solution of sodium formate (NaHCO2)?

anzhelika [568]

Answer:

9.36

Explanation:

Sodium formate is the conjugate base of formic acid.

Also,

$K_a\times K_b=K_w$

$K_b$ for sodium formate is $K_b=\frac {K_w}{K_a}$

Given that:

$K_a$ of formic acid = $1.8\times 10^{-4}$

And, $K_w=10^{-14}$

So,

$K_b=\frac {10^{-14}}{1.8\times 10^{-4}}$

$K_b=5.5556\times 10^{-11}$

Concentration = 0.35 M

HCOONa ⇒ Na⁺ + HCOO⁻

Consider the ICE take for the formate ion as:

HCOO⁻ + H₂O ⇄ HCOOH + OH⁻

At t=0 0.35 - -

At t =equilibrium (0.35-x) x x

The expression for dissociation constant of sodium formate is:

$K_{b}=\frac {[OH^-][HCOOH]}{[HCOO^-]}$

$5.5556\times 10^{-11}=\frac {x^2}{0.35-x}$

Solving for x, we get:

x = 0.44×10⁻⁵ M

pOH = -log[OH⁻] = -log(0.44×10⁻⁵) = 4.64

pH + pOH = 14

So,

5 0

3 years ago

Confused as heck. please help!

Nitella [24]

Answer: that all thre water cycle and C is vaporation

Explanation:

6 0

1 year ago

8.Which of the following is a base?

RSB [31]

Answer:

Explanation:

Unit 10 - Acid/Base ... (a) Mg(OH. 2. ) (b) Mg(OH). 2. (c) Mg. 2. OH. (d) MgOH. 2. Standard: ... balanced equation for these neutralization reactions: 3. HCl + NaOH → ... H2CO3 + Ca(OH)2 → ... C5.7B Predict products of an acid-base neutralization. 8. 2 NH4OH + H2S ...An Arrhenius base is a compound that increases the OH − ion concentration in ... and a base is called a neutralization reaction and can be represented as follows: ... chemical equation for the neutralization reaction between HCl and Mg(OH) 2. ... acid, an Arrhenius base, or neither. a) NaOH. b) C 2H 5OH. c) H 3PO 4. 6

4 0

3 years ago

What is the total number of atoms in ammonium hydroxide?<br> I will give Brainliest! :)

Karo-lina-s [1.5K]

Answer:Ammonia is a compound that contains one nitrogen atom and three hydrogen atoms. Ordinarily having a characteristic of a pungent and gaseous compound.

Elemet: Hydrogen, Symbol: H, # of Atoms:5

Elemet:Nitrogen, Symbol: N, # of Atoms:1

Elemet:Oxygen, Symbol: O, #of Atoms:1

Explanation:

6 0

2 years ago

The question is in the picture below

Rus_ich [418]

Answer:

$\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3$

Explanation:

Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.

With Hess's Law in mind, let's see how A can be converted to 2C +E.

$\bf{\text{A} \rightarrow 2\text{B}}$ (Δ $\text{H}_1$ ) -----(1)

Since we have 2B, multiply the whole of II. by 2:

$\bf{2\text{B} \rightarrow 2\text{C} +2\text{D}}$ (2Δ $\text{H}_2$ ) -----(2)

This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is $\text{A} \rightarrow 2\text{C} +2\text{D}$ .

Reversing III. gives us a negative enthalpy change as such:

$\bf{2\text{D} \rightarrow \text{E}}$ (-Δ $\text{H}_3$ ) -----(3)

This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of $\text{A} \rightarrow 2\text{C} +\text{E}$ , which is also the equation of interest.

Adding all three together:

$\text{A} \rightarrow 2\text{C}+\text{E}$ ( $\bf{\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3 }$ )

Thus, the first option is the correct answer.

Supplementary:

To learn more about Hess's Law, do check out: brainly.com/question/26491956

4 0

1 year ago