Answer:
Experimental investigations are the best type of scientific research to demonstrate the relationships between cause and effect because they allow the investigator to actively manipulate variables and control conditions. This change can be measured to gather evidence to back up or refute the relationship between cause and effect.
Answer:
The concentration of a saturated solution of CuF₂ in aqueous 0.20 M NaF is 4.0×10⁻⁵ M.
Explanation:
Consider the ICE take for the solubility of the solid, CuF₂ as:
CuF₂ ⇄ Cu²⁺ + 2F⁻
At t=0 x - -
At t =equilibrium (x-s) s 2s
The expression for Solubility product for CuF₂ is:
![K_{sp}=\left [ Cu^{2+} \right ]\left [ F^- \right ]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5Cleft%20%5B%20Cu%5E%7B2%2B%7D%20%5Cright%20%5D%5Cleft%20%5B%20F%5E-%20%5Cright%20%5D%5E2)


Given s = 7.4×10⁻³ M
So, Ksp is:


Ksp = 1.6209×10⁻⁶
Now, we have to calculate the solubility of CuF₂ in NaF.
Thus, NaF already contain 0.20 M F⁻ ions
Consider the ICE take for the solubility of the solid, CuF₂ in NaFas:
CuF₂ ⇄ Cu²⁺ + 2F⁻
At t=0 x - 0.20
At t =equilibrium (x-s') s' 0.20+2s'
The expression for Solubility product for CuF₂ is:
![K_{sp}=\left [ Cu^{2+} \right ]\left [ F^- \right ]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5Cleft%20%5B%20Cu%5E%7B2%2B%7D%20%5Cright%20%5D%5Cleft%20%5B%20F%5E-%20%5Cright%20%5D%5E2)

Solving for s', we get
<u>s' = 4.0×10⁻⁵ M</u>
<u>The concentration of a saturated solution of CuF₂ in aqueous 0.20 M NaF is 4.0×10⁻⁵ M.</u>
The answer to your questions are
Question 1 - D - stationary
Question 2 - C - I'm not 100% sure
Question 3 - A - the northern subtropical jet stream
Question 4 - A - cold
A. Organic catalysts are called enzymes.
Explanation:
The true statement of all is that organic catalysts are called enzymes. For example, saliva in the mouth is made up of different enzymes which are secreted in the human body.
- Catalysts reduces the activation energy and makes reaction proceed very fast. They generally increase the rate of chemical reactions.
- Catalysts like temperature affects the rate of chemical reaction. Chemical reactions increases as temperature increases.
- Catalysts in the human body are very useful because they help chemical reactions in the body to proceed at a much faster rate.
Learn more:
Biological catalysts brainly.com/question/8413755
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Is soluble in water but not soluble in acetonitrile.
So i think its false