There are two ways to solve this problem. We can use the ICE method which is tedious and lengthy or use the Henderson–Hasselbalch equation. This equation relates pH and the concentration of the ions in the solution. It is expressed as
pH = pKa + log [A]/[HA]
where pKa = - log [Ka]
[A] is the concentration of the conjugate base
[HA] is the concentration of the acid
Given:
Ka = 1.8x10^-5
NaOH added = 0.015 mol
HC2H3O2 = 0.1 mol
NaC2H3O2 = 0.1 mol
Solution:
pKa = - log ( 1.8x10^-5) = 4.74
[A] = 0.015 mol + 0.100 mol = .115 moles
[HA] = .1 - 0.015 = 0.085 moles
pH = 4.74 + log (.115/0.085)
pH = 4.87
Answer:
Explanation:
125 cm3 -> 0.125 L
M = no. mole / volume (L)
M = 0.25 / 0.125 = 2 M
Answer: Option (E) is the correct answer.
Explanation:
Since, the conductor is hollow which means that it is opened on both the ends. Hence, when a small uncharged metal ball is passed through it with the help of a silk thread then due to the presence of this insulating thread the ball will not come directly in contact with the charged rod.
As a result, there will occur no formation of opposite charge on the metal ball. Therefore, the ball will remain uncharged in nature.
Thus, we can conclude that after the given ball is removed, it will have no appreciable charge.
Answer:
CaCN₂
Explanation:
A compound of calcium, carbon and nitrogen CaₐCₓNₙ in oxygen will burning producing:
CaₐCₓNₙ + O₂ → aCaO + xCO₂ + nNO₂
Moles of the oxides CaO, CO₂, NO₂ are:
CaO: 3.106g ₓ (1 mole / 56.08g) = <em>0.0554 moles of CaO = moles of Ca</em>
CO₂: 2.439g ₓ (1mole / 44g) = <em>0.0554 moles CO₂ = moles C</em>
NO₂: 5.097g ₓ (1mole / 46g) = <em>0.111 moles NO₂ = moles N</em>
Empirical formula is the chemical formula that represents the simplest ratio of elements in a compound.
Having as basis 0.0554 moles (The lower number of moles):
0.0554 moles Ca / 0.0554 = 1 Ca
0.0554 moles C / 0.0554 = 1 C
0.111 moles N / 0.0554 = 2N
Thus, the compound CaₐCₓNₙ has as empirical formula:
Ca₁C₁N₂ = <em>CaCN₂</em>
