Solid Magnesium is considered as active metal so it reacts with strong acids like HCl and H₂SO₄ liberating Hydrogen gas according to the following equations:
Mg(s) + 2 HCl(aq) → MgCl₂(aq) + H₂(g)
Mg(s) + H₂SO₄(aq) → MgSO₄(aq) + H₂(g)
so the amount of solid magnesium decrease by addition of strong acid to it.
Answer:
2.28 × 10^-3 mol/L
Explanation:
The equation for the equilibrium is
CN^- + H2O ⇌ HCN + OH^-
Ka = 4.9 × 10^-10
KaKb = Kw
4.9 × 10^-10 Kb = 1.00 × 10^-14
Kb = (1.00 × 10^-14)/(4.9 × 10^-10) = 2.05 × 10^-5
Now, we can set up an ICE table
CN^- + H2O ⇌ HCN + OH^-
I/(mol/L) 0.255 0 0
C/(mol/L) -x +x +x
E/(mol/L) 0.255 - x x x
Ka = x^2/(0.255 - x) = 2.05 × 10^-5
Check for negligibility
0.255/(2.05 × 10^-5) = 12 000 > 400. ∴ x ≪ 0.255
x^2 = 0.255(2.05 × 10^-5) = 5.20 × 10^-6
x = sqrt(5.20 × 10^-6) = 2.28 × 10^-3
[OH^-] = x mol/L = 2.28 × 10^-3 mol/L
Chromosomes have genes that determine specific thing about a person (hair color, eye color, how tall or short a person is etc....).
Ca, V, Cu, Kr
Remember a period is a the horizontal rows in the Periodic Table.
Answer: pH = 4.996
Explanation:
No of moles = molarity x volume
:• no of moles of CH3COOH = 0.1M x 0.1L
n(CH3COOH) = 0.1mol
Since 0.03mole of NaOH is added, then 0.03 mole of CH3COOH will be converted to the conjugate.
Therefore, Moles of CH3COOH becomes,
0.1 - 0.03 = 0.07 mol
Subsequently, the moles of CH3COONa increases and becomes,
0.08 + 0.03 = 0.11 mol
Using the Hendersom-Hasselbach equation,
pH = pKa + log [Moles of conjugate÷ moles of Ch3COOH]
From literature, pKa of Ch3COOH is 4.8
Thus,
pH = 4.8 + log [0.11/0.07]
pH = 4.8 + 0.1963
pH = 4.996
