Answer:
number of ions = 12.04 x 10^²³
Explanation:
n = number of ions/Avogadro's constant
2 = number of ions/6.02 x 10^²³
number of ions= 2 x 6.02 x 10^²³
number of ions = 12.04 x 10^²³
0.008 ÷ 51.3 = 0.0002
Sig Figs
1
0.0002
Decimals
4
0.0002
Scientific Notation
2 × 10-4
E-Notation
2e-4
Words
zero point zero zero zero two
I HOPE I HELP
First, we must know what happens in the precipitation reaction. This type of reaction is a double replacement reactions. It is consists of two reactant compounds which interchange cations and anions to form two products. One of the products is an insoluble solid called a precipitate. For the precipitation of CaCO₃, there are two consecutive reactions involved:
1. Slaking of quicklime, CaO
CaO + H₂O ⇒ Ca(OH)₂
2. Precipitation
Ca(OH)₂ + CO₂ ⇒ CaCO₃ + H₂O
The ions that make up the H₂O molecule are H⁺ and OH⁻. According to solubility rules, the cation (positively charged ion) is likely to be attracted to an anion (negatively charged ion). Together, they form an ionic bond. This type of bond is when there is a complete transfer of electrons between the two. The Ca²⁺ cation lacks 2 electrons, while the anion OH⁻ has an excess 1 electron. In order to be stable, 1 Ca²⁺ ion and 2 OH⁻ ions must combine.
Therefore, the answer is OH⁻ ion.
Explanation:
a) Using Beer-Lambert's law :
Formula used :
where,
A = absorbance of solution = 0.945
c = concentration of solution = ?
l = length of the cell = 1.20 cm
= molar absorptivity of this solution =
(
)
14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.
b) 
1 L of solution contains 
moles of red dye.
Mass of moles of red dye:
c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.
Concentration of red dye solution = 
Concentration of red solution after dilution = c'
The final concentration of the diluted solution is 
