According to this formula :
㏑[A] /[Ao] = - Kt
when we have Ao = 0.3 m
and K =0.46 s^-1
t = 20min = 0.2 x 60 =12 s
So by substitution :
㏑[A] / 0.3 = - 0.46 * 12
㏑[A] / 0.3 = - 5.52
by taking e^x for both side of the equation we can get [A]
∴[A] = 0.0012 mol dm^-3
Answer:
Kc = 1.09x10⁻⁴
Explanation:
<em>HF = 1.62g</em>
<em>H₂O = 516g</em>
<em>F⁻ = 0.163g</em>
<em>H₃O⁺ = 0.110g</em>
<em />
To solve this question we need to find the moles of each reactant in order to solve the molar concentration of each reactan and replacing in the Kc expression. For the reaction, the Kc is:
Kc = [H₃O⁺] [F⁻] / [HF]
<em>Because Kc is defined as the ratio between concentrations of products over reactants powered to its reaction coefficient. Pure liquids as water are not taken into account in Kc expression:</em>
<em />
[H₃O⁺] = 0.110g * (1mol /19.01g) = 0.00579moles / 5.6L = 1.03x10⁻³M
[F⁻] = 0.163g * (1mol /19.0g) = 0.00858moles / 5.6L = 1.53x10⁻³M
[HF] = 1.62g * (1mol /20g) = 0.081moles / 5.6L = 0.0145M
Kc = [1.03x10⁻³M] [1.53x10⁻³M] / [0.0145M]
<h3>Kc = 1.09x10⁻⁴</h3>
B. eating the right amount of calories each day
for a, you need proteins,veggies and calories to survive, as each does a specific job such as glucose and protein being created, etc.
For c, you can have at least 1 item from each food group each day, but you can still have too much of something and thats harmful.
For d,getting 100% calcium only works with calcium, and you can do anything with the other foods.
For b(which is correct), people usually eat an excess of calories, and that mainly controls your weight. Now other food groups can also affect you if you have too much, but people tend to have too much calories, so getting the right amount of calories is the best choice
Answer:
See the answer below
Explanation:
The best approach would be to <u>pour the liquid from the large reagent bottle into a small-size beaker or reagent bottle first</u>, before measuring the required quantity out into the reaction vessel. This is necessary in order to maintain safety in the laboratory.
Pouring the liquid directly from the large reagent bottle into the measuring cylinder or directly into the reaction bottle can compromise safety in the laboratory. The liquid might splash out and cause harm to the handler or create other harmful circumstances in the laboratory.
