Answer:
1 × 10⁸ He atoms
Explanation:
Step 1: Given data
- Diameter of a helium atom (d): 1 × 10² pm
- Total distance to be covered (D): 1 cm
Step 2: Convert "d" to meters
We will use the conversion factor 1 m = 10¹² pm.
1 × 10² pm × (1 m / 10¹² pm) = 1 × 10⁻¹⁰ m
Step 3: Convert "D" to meters
We will use the conversion factor 1 m = 100 cm.
1 cm × (1 m / 100 cm) = 0.01 m
Step 4: Calculate the number of atoms of He required
We will use the following expression.
D/d = 0.01 m / 1 × 10⁻¹⁰ m = 1 × 10⁸
Explanation:
It is given that the total volume is (10 mL + 60 mL) = 70 mL.
Also, it is known that =
Where, = total volume
= initial volume
Therefore, new concentration of =
=
= 0.43 M
New concentration of NaOH =
=
= 0.14 M
So, the given reaction will be as follows.
Initial: 0.43 0.14 0
Change: -0.14 -0.14 0.14
Equilibrium: 0.29 0 0.14
As it is known that value of = 4.74
Therefore, according to Henderson-Hasselbalch equation calculate the pH as follows.
pH =
=
= 4.74 + (-0.316)
= 4.42
Therefore, we can conclude that the pH of given reaction is 4.42.
Answer:
The two-step mechanism is a slow mechanism and a fast mechanism. When we combine them, the result is
2H₂O₂ (aq) ⇒2H₂O (l) + O₂ (g)
Explanation:
We know that the decomposition of hydrogen peroxide is catalyzed by iodide ion, which means that the iodide ion will react with the hydrogen peroxide. There is a slow mechanism and a fast one:
H₂O₂(aq) + I₋(aq) ⇒ H₂O(l) + IO₋(aq) this is the slow reaction
IO₋(aq) + H₂O₂(aq)⇒ H₂O(l) + O₂(g) + I₋ (aq) this is the fast reaction
If we cancel the same type of molecules and ions, the final result is:
2H₂O₂ (aq) ⇒2H₂O (l) + O₂ (g)
We can exemplify with H2O (water)
H= nonmetalic
O= Nonmetalic
A bond with nonmetalic and nonmetalic is covalent bond.
Hope it helps!!
#MissionExam001
<span>Sample #2 and sample #3 must have the equal volume as sample #1 ,if the masses of the both samples are equal to mass of sample #1.
Otherwise, the volume would vary if the masses are not equal.</span>