Solution:
We have to use the Henderson-Hasselbalch equation: for this calculation
Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity by using pKa, the negative log of the acid dissociation constant in biological and chemical systems. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid-base reaction.
The equation is given by:
Here, [HA] is the molar concentration of the un dissociated weak acid, [A⁻] is the molar concentration (molarity, M) of this acid's conjugate base and pKa is −log10 Ka where Ka is the acid dissociation constant, that is:
pH = pKa + log([A^-]/[HA])
We look up the pKa for acetic acid:
pKa = 4.76
Let x = molarity of AcO^- and y = molarity of AcOH: Then we have the following two equations in two unknowns:
(1) x + y = 0.10 M
and
(2) 4.9 = 4.76 + log(x/y)
Further calcite the value of x and y by algebraic method and get the answer.
Answer:
Explanation:
1.
Given parameters:
Number of moles of CaO = 0.22moles
Unknown:
Mass of CaO = ?
Solution:
Mass, number of moles and molar mass are related using the expression below;
Mass = number of moles x molar mass
Molar mass of CaO = 40 + 16 = 56g/mol
Insert the parameters and solve;
Mass = 0.22 x 56 = 12.32g
2
Given parameters:
Number of moles of NaCl = 0.83moles
Unknown:
mass of NaCl = ?
Solution:
Also,
Mass = number of moles x molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Now insert the parameters and solve;
mass = 0.83 x 58.5
mass = 48.6g
3.
Given parameters:
Number of moles of H₂SO₄ = 0.5moles
Unknown:
mass of H₂SO₄ = ?
Solution:
Mass = number of moles x molar mass
Molar mass of H₂SO₄ = 2(1) + 32 + 4(16) = 98g/mol
Insert the parameters and solve;
Mass = 0.5 x 98 = 49g
Water has greatest boiling and melting points because strong hydrogen bonds between water molecules (intermolecular force). That is because oxygen has largest electronegativity and smallest atomic radius of all elements in group. Other elements in this group do not form hydrogen bonds and they are gasses in room temperature, water is liquid and their boiling and melting points are lower. Boiling and melting point of hydrides gradually increases from H₂S to H₂Te because of increase of the radius and molecular mass of atoms from sulfur to tellurium, that is why intermolecular force of attraction of molecules increases. <span>
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Answer:
127.15 g of ZnCl₂
Solution:
The balance chemical equation is as follow,
<span> Zn + 2 HCl </span>→ ZnCl₂ + H₂
According to equation,
65.38 g (1 mole) of Zn produced = 136.28 g (1 mole) of ZnCl₂
So,
61.0 g of Zn will produce = X g of ZnCl₂
Solving for X,
X = (61.0 g × 136.28 g) ÷ 65.38 g
X = 127.15 g of ZnCl₂
Answer:
attachment, penetration, uncoating, replication, assembly, and release.
Explanation: