Answer:
Molarity = 0.7 M
Explanation:
Given data:
Volume of KCl = 20 mL ( 0.02 L)
Molarity = 3.5 M
Final volume = 100 mL (0.1 L)
Molarity in 100 mL = ?
Solution:
Molarity = number of moles of solute / volume in litter.
First of all we will determine the number of moles of KCl available.
Number of moles = molarity × volume in litter
Number of moles = 3.5 M × 0.02 L
Number of moles = 0.07 mol
Molarity in 100 mL.
Molarity = number of moles / volume in litter
Molarity = 0.07 mol /0.1 L
Molarity = 0.7 M
The Earth's crust or is it the continental plates one of the two but they push against each other costing a tsunami.
Answer:
1.12 × 10⁻⁴ M
Explanation:
Step 1: Write the reaction for the solution of Mg(OH)₂
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
Step 2: Make an ICE chart
We can relate the solubility product constant (Ksp) with the solubility (S) through an ICE chart.
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
I 0 0
C +S +2S
E S 2S
The solubility product constant is:
Ksp = 5.61 × 10⁻¹² = [Mg²⁺] × [OH⁻]² = S × (2S)² = 4S³
S = 1.12 × 10⁻⁴ M
The answer is 64.907 amu.
The atomic mass of an element is the average of the atomic masses of its isotopes. The relative abundance of isotopes must be taken into consideration, therefore:
atomic mass of copper = atomic mass of isotope 1 * abundance 1 + atomic mass of isotope 2 * abundance 2
We know:
atomic mass of copper = 63.546 amu
The atomic mass of isotope 1 is: 62.939 amu
The abundance of isotope 1 is: 69.17% = 0.6917
The atomic mass of isotope 1 is: x
The abundance of isotope 2: 100% - 69.17% = 30.83% = 0.3083
Thus:
63.546 amu = 62.939 amu * 0.6917 + x * 0.3083
63.546 <span>amu = 43.535 amu + 0.3083x
</span>⇒ 63.546 amu - 43.535 amu = 0.3083x
⇒ 20.011 amu = 0.3083x
⇒ x = 20.011 amu ÷ 0.3083 = 64.907 amu
The correct answer among the choices given is the first option.The teacher most likely is talking about distillation of a mixture. Distillation is a unit operation that separates component substances from a liquid mixture which is shown by the teacher. Also, the most common purifying technique in the production of gasoline is by this process.
