Answers
Answer:
Explanation:
# moles that exist in 1.9 X 10 23 =
= # of atoms/# of Avogadro 's num
= 1.9 X 10 23 / 6.02x10 23
= 0.266 mole of Pb
now we calculate the mass
mass of lead = # mol x m.wt
= 0.266 X 106.4
= 28.30 gram
Related Questions
A compound is found to contain 18.28 % phosphorus , 18.93 % sulfur , and 62.78 % chlorine by mass. To answer the question, enter the elements in the order presented above. QUESTION 1: The empirical formula for this compound is . QUESTION 2: The molar mass for this compound is 169.4 g/mol. The molecular formula for this compound is
Will MARK U AS BRAINLIEST IF U GIVE RIGHT ANSWER
A pharmacist wishes to strengthen a mixture from 10%alcohol to 30% alcohol. How much pure alcohol should be added to 7 liters of the 10% mixture?
Which best describes a codon?
Answers
Answer:
c. CH3CH2CH(CH3)CHO
Explanation:
Hello there!
In this case, according to the process for the one-step oxidation of a primary alcohol with a moderately strong oxidizing agent like pyridinium chlorochromate (PCC), whereby an aldehyde is produced, we infer that the corresponding product will be 2-methylbutanal, which matches with the choice c. CH3CH2CH(CH3)CHO according to the following reaction:
Regards!
Answers
Answer : The volume of calcium hydroxide is, 32.89 ml
Explanation :
Using neutralization law,
where,
= basicity of an acid = 1
= acidity of a base = 2
= concentration of hydrobromic acid = 0.389 M
= concentration of calcium hydroxide = 0.0887 M
= volume of hydrobromic acid = 15 ml
= volume of calcium hydroxide = ?
Now put all the given values in the above law, we get the volume of calcium hydroxide.
Therefore, the volume of calcium hydroxide is, 32.89 ml
b. False
Answers
Answer:
a. True
Explanation:
Distillation process is a process that is used to separate the components or the substances from the liquid mixtures by using selectively boiling and condensation.
While fractional precipitation is a process which separates the ions from solution based on the different solubilities.
Therefore, the answer is true.
Answers
Answer:
pH at the equivalence point is 8.6
Explanation:
A titulation between a weak acid and a strong base, gives a basic pH at the equivalence point. In the equivalence point, we need to know the volume of base we added, so:
mmoles acid = mmoles of base
60 mL . 0.1935M = 0.2088 M . volume
(60 mL . 0.1935M) /0.2088 M = 55.6 mL of KOH
The neutralization is:
HBz + KOH ⇄ KBz + H₂O
In the equilibrum:
HBz + OH⁻ ⇄ Bz⁻ + H₂O
mmoles of acid are: 11.61 and mmoles of base are: 11.61
So in the equilibrium we have, 11.61 mmoles of benzoate.
[Bz⁻] = 11.61 mmoles / (volume acid + volume base)
[Bz⁻] = 11.61 mmoles / 60 mL + 55.6 mL = 0.100 M
The conjugate strong base reacts:
Bz⁻ + H₂O ⇄ HBz + OH⁻ Kb
0.1 - x x x
(We don't have pKb, but we can calculate it from pKa)
14 - 4.2 = 9.80 → pKb → 10⁻⁹'⁸ = 1.58×10⁻¹⁰ → Kb
Kb = [HBz] . [OH⁻] / [Bz⁻]
Kb = x² / (0.1 - x)
As Kb is so small, we can avoid the quadratic equation
Kb = x² / 0.1 → Kb . 0.1 = x²
√ 1.58×10⁻¹¹ = [OH⁻] = 3.98 ×10⁻⁶ M
From this value, we calculate pOH and afterwards, pH (14 - pOH)
- log [OH⁻] = pOH → - log 3.98 ×10⁻⁶ = 5.4
pH = 8.6
Final answer:
To calculate the pH at equivalence in a titration, we need to consider the concentration of the excess strong base in the solution. First, we calculate the moles of the acid and the base, then we find the moles of the excess base. Using this information, we can find the concentration of the excess base and subsequently calculate pOH. Finally, we can convert pOH to pH using the pH + pOH = 14 relationship.
Explanation:
pH at the equivalence point in a titration can be determined by considering the concentration of the excess strong base present in the reaction mixture. In this case, the excess strong base is KOH. We can calculate [OH-] using the stoichiometry of the reaction and the given concentrations. Then, we can find the pOH using the formula -log[OH-]. Finally, we can convert pOH to pH using the pH + pOH = 14 relationship.
Given:
- Volume of benzoic acid solution (HC (H5CO2)): 60.0 mL
- Concentration of benzoic acid solution: 0.1935 M
- Concentration of KOH solution: 0.2088 M
Step 1: Determine the amount of benzoic acid (HC (H5CO2)) in moles:
moles of HC (H5CO2) = volume (L) × concentration (M) = 0.0600 L × 0.1935 M = 0.01161 mol
Step 2: Determine the amount of KOH in moles:
moles of KOH = volume (L) × concentration (M) = 0.0600 L × 0.2088 M = 0.01253 mol
Step 3: Determine the amount of excess KOH in moles:
moles of excess KOH = moles of KOH - moles required for neutralizing HC (H5CO2) = 0.01253 mol - 0.01161 mol = 9.2 × 10-4 mol
Step 4: Determine the concentration of excess KOH:
concentration of excess KOH = moles of excess KOH / volume (L) = 9.2 × 10-4 mol / 0.0600 L = 0.0153 M
Step 5: Determine the pOH of the solution:
pOH = -log[OH-] = -log(0.0153) ≈ 1.82
Step 6: Determine the pH of the solution:
pH = 14 - pOH = 14 - 1.82 ≈ 12.18
Learn more about pH at equivalence point here:
#SPJ3
Answers
Answers
Answer:
The correct answer is the tendency of all the elements to react with every other element.
Explanation:
A component in which two or more elements are bonded chemically leads to the production of a compound. A compound refers to a pure component as it comprises elements that are in their pure state. The formation of a compound takes place when the elements react with each other based upon their reactivity.
For example, the element chlorine is deficient of one electron and the element sodium exhibits one additional electron. Thus, chlorine easily reacts with the sodium in order to obtain stability. Therefore, the formation of sodium chloride takes place. Hence, it can be concluded that the tendency of all the elements to react with every other element is the condition, which is possible to influence the probable number of compounds.