Answer:
a. 2954g of FeS
b. 1143g of FeS
Explanation:
Based on the reaction:
8 Fe + S₈ → 8 FeS
<em>8 moles of Fe reacts with 1 mole of S₈ to produce 8 moles of FeS</em>
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a. 4.2mol sulfur produce:
4.2mol S₈ × ( 8 mol FeS / 1 mol S₈) = <em>33.6mol FeS</em>. As molar mass of FeS is 87.92g/mol, mass is:
33.6mol FeS × ( 87.92g / 1 mol FeS) = <em>2954g of FeS</em>
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b. 13mol Fe produce:
13mol Fe × ( 8 mol FeS / 8 mol Fe) = <em>13mol FeS</em>. In mass:
13 mol FeS × ( 87.92g / 1 mol FeS) = <em>1143g of FeS</em>
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
Answer:
mass
Explanation:
The amount of kinetic energy an object has, depends on its mass and its speed.
