Answer:
pH after the addition of 10 ml NaOH = 4.81
pH after the addition of 20.1 ml NaOH = 8.76
pH after the addition of 25 ml NaOH = 8.78
Explanation:
(1)
Moles of butanoic acid initially present = 0.1 x 20 = 2 m moles = 2 x 10⁻³ moles,
Moles of NaOH added = 10 x 0.1 = 1 x 10⁻³ moles
CH₃CH₂CH₂COOH + NaOH ⇄ CH₃CH₂CH₂COONa + H₂O
Initial conc. 2 x 10⁻³ 1 x 10⁻³ 0
Equilibrium 1 x 10⁻³ 0 1 x 10⁻³
Final volume = 20 + 10 = 30 ml = 0.03 lit
So final concentration of Acid =
Final concentration of conjugate base [CH₃CH₂CH₂COONa]
Since a buffer solution is formed which contains the weak butanoic acid and conjugate base of that acid .
Using Henderson Hasselbalch equation to find the pH
During titration of butanoic acid with NaOH, we can calculate the pH at various points using the Henderson-Hasselbalch equation for buffer scenarios. After 10.00mL of NaOH, the pH will be 4.74. After 20.10 mL, the pH will be 8.27, and after 25.00 mL, the pH will be 12.30.
This involves calculating the pH at various stages during a titration procedure. Here the titration involves a weak acid, butanoic acid, with a strong base, NaOH. We can simplify the reaction as follows: CH₃CH₂CH₂COOH + OH- --> CH₃CH₂CH₂COO- + H₂O.
(a) After 10.00 mL of NaOH is added, the system isn't at equivalence. Here, the reaction hasn't fully completed and a buffer solution is present. Using the Henderson-Hasselbalch equation, we can find the pH: pH = pKa + log([base]/[acid]). After calculating, we can find pH = 4.74.
(b) After 20.10 mL NaOH is added, the system reaches past equivalence. The pH can be determined by finding pOH using the remaining OH- concentration and then subtracting from 14. After the calculation, the pH = 8.27.
(c) For 25.00 mL of NaOH, the system is beyond equivalence and extra OH- ions increase pH. The pH calculation is like previous step and the result will be pH = 12.30.
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Answer:
A chemical reaction is the process in which atoms present in the starting substances rearrange to give new chemical combinations present in the substances formed by the reaction. These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.
Answer:
One molecule
Explanation
But there is three different atoms forming this one NaOH. The three atoms are Na, O and H, that is one sodium, one oxygen, and one hydrogen.
Answer:
38.96383282 amu
Explanation:
39.0983 = (40.9618 0.067302) + ( ? (1-0.067302)
39.0983 = 2.756811064 + ( ? 0.932698)
subtract 2.756811064 from both sides
36.34148894 = ( ? 0.932698)
divide both sides by 0.932698
? = 38.96383282 amu
Answer:
38.96383282 amu
Explanation:
39.0983 = (40.9618 0.067302) + ( ? (1-0.067302)
39.0983 = 2.756811064 + ( ? 0.932698)
subtract 2.756811064 from both sides
36.34148894 = ( ? 0.932698)
divide both sides by 0.932698
? = 38.96383282 amu
Answer:
54%
Explanation:
The balanced equation is:
The first step is to determine the limiting reactant. For this, we calculate the moles of each given component and divide the result for the stoichiometric coefficient.
3.4 g octane / 114.23 g/mol = 0.030 mol octane
0.030 mol octane/2=0.015
5.9 g O2 / 32 g/mol = 0.18 mol O2
0.18 mol O2/25= 0.0074 mol
The lower number, in this case oxygen, is the limiting reactant. The value corresponds to the theoretical yield of the reaction.
Similarly, the real yield is calculated from the product.
2.80 g CO2/ 44.01 g/mol = 0.0636 mol CO2
0.0636 mol CO2/16 = 0.00398 mol
The percent yield is the ratio of the 2 multiplied by a hundred, then
Percent yield= 0.0398/0.0074 *100 = 54%
The percent yield of carbon dioxide from the combustion reaction of octane and oxygen, given the provided masses of the reactants and the yield of CO2, is calculated to be 26.7%
The combustion of octane in oxygen yields carbon dioxide and water in a 1:1 ratio, as the balanced chemical equation for the reaction is 2C8H18 + 25O2 -> 16CO2 + 18H2O. To calculate the percent yield of CO2, we first need to determine the theoretical yield of CO2. We can use the provided masses of octane and O2 and their respective molar masses to calculate the number of moles of each reactant:
- Moles of octane = 3.4 g / 114.22 g/mol = 0.0298 mol
- Moles of O2 = 5.9 g / 32.00 g/mol = 0.184 mol
Now, using the stoichiometric relationship from the balanced chemical equation, we can calculate the theoretical yield of CO2:
- Theoretical yield = 0.0298 mol octane x 16 mol CO2/2 mol octane = 0.238 mol CO2
Next, we convert this to grams using the molar mass of carbon dioxide:
- Theoretical yield = 0.238 mol CO2 x 44.01 g/mol = 10.5g CO2
Now that we have both the actual yield (2.80 g) and the theoretical yield (10.5 g), we can calculate the percent yield:
- Percent yield = (actual yield / theoretical yield) x 100% = (2.80 g / 10.5 g) x 100% = 26.7%
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Answer:
C₆H₆
Explanation:
Each border of the figure represents 1 atom of carbon. We have 6 borders = 6 atoms of carbon.
Each atom of carbon form 4 bonds. All the carbons are doing a double bond and a single bond with other carbons. That means are bonded 3 times. The other bond (That is not represented in the figure. See the image) comes from hydrogens. As we have 6 carbons that are bonded each 1 with one hydrogen. There are six hydrogens and the molecular formula is:
This structure is: Benzene
Answer: The concentration of solution is 0.342 M
Explanation:
To calculate the molarity of solution, we use the equation:
We are given:
Mass of solute (Sodium chloride) = 15 g
Molar mass of sodium chloride = 58.5 g/mol
Volume of solution = 750 mL
Putting values in above equation, we get:
Hence, the concentration of solution is 0.342 M