Answer:
BaC₂O₄, then ZnC₂O₄, then Ag₂C₂O₄
Explanation:
1. Calculate the equilibrium concentrations of oxalate ion
Let [C₂O₄²⁻] = c
(a) Barium oxalate
BaC₂O₄ ⇌ Ba²⁺ + C₂O₄²⁻
E/mol·L⁻¹: 5.0 × 10⁻⁵ c
Ksp = [Ba²⁺][C₂O₄²⁻] = 5.0 × 10⁻⁵c = 1.5 × 10⁻⁸
c = (1.5 × 10⁻⁸)/(5.0 × 10⁻⁵) = 3.0 × 10⁻⁴ mol·L⁻¹
(b) Zinc oxalate
ZnC₂O₄ ⇌ Zn²⁺ + C₂O₄²⁻
E/mol·L⁻¹: 2.0 × 10⁻⁷ c
Ksp = [Zn²⁺][C₂O₄²⁻] = 2.0 × 10⁻⁷c = 1.35 × 10⁻⁹
c = (1.35 × 10⁻⁹)/(2.0 × 10⁻⁷) = 6.8 × 10⁻³ mol·L⁻¹
(c) Silver oxalate
Ag₂C₂O₄ ⇌ 2Ag⁺ + C₂O₄²⁻
E/mol·L⁻¹: 3.0 × 10⁻⁵ c
Ksp = [Ag⁺]²[C₂O₄²⁻] = (3.0× 10⁻⁵)²c = 9.0 × 10⁻¹⁰c = 1.1 × 10⁻¹¹
c = (1.1 × 10⁻¹¹)/(9.0 × 10⁻¹⁰) = 0.012 mol·L⁻¹
2. Decide the order of precipitation
BaC₂O₄ will precipitate when c > 3.0 × 10⁻⁴ mol·L⁻¹
ZnC₂O₄ will precipitate when c > 6.8 × 10⁻³ mol·L⁻¹
Ag₂C₂O₄ will precipitate when c > 0.028 mol·L⁻¹
This happens to be the order of increasing concentration of oxalate ion.
The order of precipitation is
BaC₂O₄, then ZnC₂O₄, then Ag₂C₂O₄
The Environmental Protection Agency (EPA) refrigerant management regulations would exempt any refrigerant from venting problem when it determines that the refrigerant in an appliance do not pose a threat to the environment (surrounding) if released.
A refrigerant can be defined as any chemical substance that undergoes a phase change (liquid and gas) so as to enable the cooling and freezing of materials. They are typically used in air conditioners, refrigerators, water dispensers, etc.
In the United States of America, the Environmental Protection Agency (EPA) is a governmental agency which was established by U.S Congress and it is saddled with the responsibility of overseeing all aspects of pollution, environmental clean up, degradation, pesticide use, contamination, and hazardous waste spills. Also, EPA research solutions, policy development, and enforcement of regulations through the resource Conservation and Recovery Act.
Simply stated, the Environmental Protection Agency (EPA) is the governmental agency set up to ensure that various industries, factories and people comply with laws and regulations concerning the environment.
In conclusion, appliances such as a refrigerator, air conditioner (AC), etc., whose refrigerants do not pose a threat (potentially cause damage) to the environment if released are typically exempted by the EPA's refrigerant management regulations.
Answer:
<u>Heating water with an open flame</u>
<u>Explanation:</u>
Remember, we are told in the label that Acetone is a "flammable liquid and vapor." <em>Being flammable means the substance can easily be set on fire</em>, and we would expect an open flame from heating water to trigger an explosion (a disaster) in which the Acetone is set on fire causing life-threatening dangers to the second group of students.
Answer:
Chromosphere
Explanation:
You see the middle layer of the sun’s atmosphere, the Chromosphere, at the start and end of a total eclipse.
