Answer:
9.1
Explanation:
Step 1: Calculate the basic dissociation constant of propionate ion (Kb)
Sodium propionate is a strong electrolyte that dissociates according to the following equation.
NaC₃H₅O₂ ⇒ Na⁺ + C₃H₅O₂⁻
Propionate is the conjugate base of propionic acid according to the following equation.
C₃H₅O₂⁻ + H₂O ⇄ HC₃H₅O₂ + OH⁻
We can calculate Kb for propionate using the following expression.
Ka × Kb = Kw
Kb = Kw/Ka = 1.0 × 10⁻¹⁴/1.3 × 10⁻⁵ = 7.7 × 10⁻¹⁰
Step 2: Calculate the concentration of OH⁻
The concentration of the base (Cb) is 0.24 M. We can calculate [OH⁻] using the following expression.
[OH⁻] = √(Kb × Cb) = √(7.7 × 10⁻¹⁰ × 0.24) = 1.4 × 10⁻⁵ M
Step 3: Calculate the concentration of H⁺
We will use the following expression.
Kw = [H⁺] × [OH⁻]
[H⁺] = Kw/[OH⁻] = 1.0 × 10⁻¹⁴/1.4 × 10⁻⁵ = 7.1 × 10⁻¹⁰ M
Step 4: Calculate the pH of the solution
We will use the definition of pH.
pH = -log [H⁺] = -log 7.1 × 10⁻¹⁰ = 9.1
1) Radium will form Ra²⁺ ions, because it is metal with two valence electrons (7s²) and it will lost two electrons to have electric configuration like noble gas radon (Z=86).
Electroic configuration of radium atom:
₈₈Ra 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰4f¹⁴5s²5p⁶5d¹⁰6s²6p⁶7s².
2) Selenium wil form Se²⁻ ions, because it is nonmetal and it has six valence electrons (4s²4p⁴), it will gain two electrons to have electron configuration like noble gas krypton (Z=36).
Electronic configuration of selenium atom: ₃₄Se 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁴.
Answer:
The final volume of the metal and water is 54.46mL
Explanation:
Hello,
To solve this question, we'll first of all find the volume of the metal and assuming there's no loss of water by overflow in the container, we'll add the volume of the metal to the volume of the water to get the final volume.
Data;
Mass of the metal = 45.5g
Volume of the water = 45mL
Density of the metal (ρ) = 3.65g/mL
Density of the metal = mass / volume
ρ = mass / volume
Volume (v) = mass / density
Volume = 45.5 / 3.65
Volume = 12.46mL
The volume of the metal is 12.46mL.
When the metal is added to the container 45mL of water, assuming no water was lost by overflow in the container, the final volume =
Final volume = volume of metal + volume of water
Final volume = 12.46 + 45.0
Final volume = 57.46mL
The final volume of the metal and water is 57.46mL
Curiosity because the scientist is curious about the blood thinning agent
