Answer:
[CaCl₂] = 1.32 M
Explanation:
We know the volume of solution → 0.30 L
We know the mass of solute → 44 g of CaCl₂
Let's convert the mass of solute to moles.
44 g . 1 mol / 110.98 g = 0.396 moles
Molarity (mol/L) → 0.396 mol / 0.3 L = 1.32 M
Answer:
Copper ions are reduced into copper atoms.
Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎
Explanation:
During electrolysis, the positive H⁺ and Cu⁺ ions move to the negative cathode and negative OH⁻ and Cl⁻ ions move to the positive anode.
At cathode, copper ions are preferentially discharged due to the low electromotive force required to discharge them compared to the hydrogen ion. The copper ions gain the two electrons lost by the chloride ions when the are discharged. (2 Cl⁻₍aq₎ → Cl₂₍g₎ + 2e⁻)
Thus the half equation is as follows:
Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎
The question is asking us to determine what gives the Amethyst its purplish color. Amethyst colors range from light to dark purple. The most highly regarded are the transparent deep purple colors. Amethyst ( chemical formula: Si O2 ) is the purple variety of the mineral Quartz.The pure Quartz is often colorless. Amethyst gets its purplish color because of the presence of Iron ( Fe ) and other impurities in the gem. Answer: C. Iron.<span /><span />
Answer:
The final dilution is 1:400
Explanation:
Let's analyze what we are told: we have an initial 1:5 dilution of protein lysate. This means that the initial solution (stock solution) was diluted 5 times. Then, from this dilution the student prepared another dilution taking 2 mL of the first dilution in 8 mL of water. This is the same as saying we took 1 mL of first dilution in 4 mL of water (the ratio is the same), so we now have a second 1:4 dilution of the first dilution (1:5). Finally, the student made a third 1:20 dilution, this means that the second dilution was further diluted 20 times.
So, to calculate the final dilution of protein lysate, we have to multiply all the dilution factors of every dilution prepared: in this case we have a final dilution of 1:20, this means we have a factor dilution of 20. But it was previously diluted 4 times, so we have a factor dilution of 20×4 = 80. However, this dilution was also previously diluted 5 times, so the new dilution factor is 80 × 5 = 400
This means that the final dilution of the compound was diluted a total of 400 times compared to the initial concentration of stock solution.
