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Both America and Kenya have a high level of possible crop damage by insects. America is able to afford insecticides and the research to go with it, to control the pests. In Kenya farmers rotate their crops as much as possible (not always possible) and this helps in reducing the risk of pests. Also Kenyan farmers often grow rice in adjacent fields with sweet potatoes; this has reduced the weevil infestation level in sweet potatoes. The same technique can be used using sweet potato, intercropped with millet and sesame.
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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
The liquid to solid process using the particle theory is as below
- The process that involve change of liquid to solid is known as Freezing
- It involve change from a high energy state to lower energy
- The constant temperature at which a liquid change to solid by giving out heat energy is called freezing point of the liquid
- when liquid are cooled the thermal energy of particles decrease.
- The cohesive forces between the particles strengthen to such extent that particles can have relative motion with each other and they occupy the fixed position, thus liquid is converted to solid
Answer:
i think is c,my ans will not be 100%correct
Answer: B= 210 amps
Explanation:
175
0.75 so you divide it so the answer it 210
since first you find for one
then you multiply 0.75 to the answer you get
Hope this helps :)
