Answers
Answer:
i) pH = 0.6990
ii) pH = 2.389
Explanation:
i) Before adding aqueous NaOH, there are 25.00 mL of 0.2000 M HCl. HCl reacts with the water in the aqueous solution as follows:
HCl + H₂O ⇒ H₃O⁺ + Cl⁻
The HCl and H₃O⁺ are related to each other through a 1:1 molar ratio, so the concentration of H₃O⁺ is equal to the HCl concentration.
The pH is related to the hydronium ion concentration as follows:
pH = -log([H₃O⁺]) = -log(0.2000) = 0.699
ii) Addition of NaOH causes the following reaction:
H₃O⁺ + NaOH ⇒ 2H₂O + Na⁺
The H₃O⁺ and NaOH react in a 1:1 molar ratio. The amount of NaOH added is calculated:
n = CV = (0.2000 mol/L)(24.00 mL) = 4.800 mmol NaOH
Thus, 4.800 mmol of H₃O⁺ were neutralized.
The initial amount of H₃O⁺ present was:
n = CV = (0.2000 mol/L)(25.00 mL) = 5.000 mmol H₃O⁺
The amount of H₃O⁺ that remains after addition of NaOH is:
(5.000 mmol) - (4.800 mmol) = 0.2000 mmol
The concentration of H₃O⁺ is the amount of H₃O⁺ divided by the total volume. The total volume is (25.00 mL) + (24.00 mL ) = 49.00 mL
C = n/V = (0.2000 mmol) / (49.00 mL) = 0.004082 M
The pH is finally calculated:
pH = -log([H₃O⁺]) = -log(0.004082) = 2.389
Related Questions
Is my answer right? How many millilitres of 1.33 mol L−1 H2SO4(aq) are required to completely neutralize 49.3 mL of 0.830 mol L−1 KOH(aq) ? I got 15.4 once and now I got 61.4? Are they correct? if so, which one?
6 CO2 + 6 H2OHow many atoms of each element are inthe equation?
Be sure to answer all parts. (a) How many atoms are directly bonded to the central atom in a trigonal planar molecule? i. two ii. three iii. six iv. eight (b) How many atoms are directly bonded to the central atom in a trigonal bipyramidal molecule? i. three ii. four iii. five iv. six (c) How many atoms are directly bonded to the central atom in an octahedral molecule? i. three ii. four iii. six iv. eight
Using a density of 1.0 g/mL for the water added and adding in the mass of the lithium nitrate, what is the total mass of the solution?
IR data: 3400 (broad), 3250 (broad), 1590, 820 cm^(-1).
Draw your proposed structure below.
Answers
Answer:
Please refer to the attachment below.
Explanation:
Please refer to the attachment below for explanation.
41.0 + 78.3 =
Answers
Ans: 1) 1.41
2) 119.3
While adding two numbers, the rule of significant figures requires that the number of decimal places in the final answer is equal to that of the term with the least decimal places
In the given examples:
1) 0.09 - has 2 decimal places
1.324- has 3 decimal places
Sum = 0.09 + 1.324 = 1.414
Round off to 2 decimal places = 1.41
2) 41.0 - has 1 decimal place
78.3- has 1 decimal place
Sum = 41.0 + 78.3 = 119.3
Final answer will also have 1 decimal place = 119.3
1. 1.141
2. 119.3
HOPE THIS HELPS.
Onoble gases
O halogens
O transitional metals
Answers
Final answer:
Group/Family 18 on the periodic table is called the noble gases.
Explanation:
Group/Family 18 on the periodic table is called the noble gases. The noble gases are a group of chemical elements that have full valence electron shells, which makes them stable and nonreactive. This group includes elements like helium, neon, argon, krypton, xenon, and radon.
Learn more about Noble gases on the periodic table here:
Answers
Answer: 40.496%
Hope this helps! (:
Answers
Answer:
False
Explanation:
Magnesium is the element of second group and third period. The electronic configuration of magnesium is - 2, 8, 2 or
There are 2 valence electrons of magnesium.
Only the valence electrons are shown by dots in the Lewis structure.
As, stated above, there are only two valence electrons of magnesium, so in the Lewis structure, two dots are made around the magnesium symbol.
Given that the electronic configuration is:- .
Orbital s cannot accommodate 3 electrons and also in magnesium it has . Hence, the statement is false.
Answers
Final answer:
Buffer capacity denotes how much acid or base a buffer solution can integrate before alterations in pH becomes significant. It is crucial in maintaining physiological activities, particularly in blood pH regulation. The substance absorbing the ions is typically a weak acid/base and their conjugates.
Explanation:
Buffer capacity is the amount of acid or base a buffer solution can accommodate before the pH is significantly pushed outside of the buffer range. Solutions that contain sizable quantities of a weak conjugate acid-base pair are known as buffer solutions. These usually experience only slight changes in pH when small amounts of acid or base are added.
A large enough addition of these substances can exceed the buffer capacity, consuming most of the conjugate pair and leading to a drastic change in pH. In living organisms, a variety of buffering systems exist to maintain the pH of blood and other fluids within a strict range between pH 7.35 and 7.45, ensuring normal physiological functioning.
The substance that absorbs the ions is usually a weak acid, which absorbs hydroxyl ions, or a weak concentrate base, which absorbs hydrogen ions. The buffer capacity is greater in solutions that contain more of this weak acid/base and their conjugates.
Learn more about Buffer Capacity here:
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Final answer:
Buffer capacity refers to the amount of acid or base that a buffer solution can absorb before experiencing a significant shift in pH, commonly by one pH unit.
Explanation:
Buffer capacity is the amount of acid or base a buffer can handle before pushing the pH outside of the buffer range. Essentially, it is a measure of a buffer's resistance to pH change upon the addition of an acid or base. Buffer capacity depends on the concentrations of the weak acid and its conjugate base present in the mixture. For instance, a solution with higher concentrations of acetic acid and sodium acetate will have a greater buffer capacity than a more dilute solution of the same components. The buffer's capacity is directly proportional to its ability to absorb strong acids or bases before there's a significant change in pH, typically defined as a shift by one pH unit.
Learn more about Buffer Capacity here:
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