The answer is C. Because you need the sun to start your cycle which starts with water evaporation
Explanation:
When there occurs sharing of electrons between two chemically combining atoms then it forms a covalent bond. Generally, a covalent bond is formed between two non-metals.
An ionic bond is defined as the bond formed due to transfer of one or more number of electrons from one atom to another. An ionic bond is always formed between a metal and a non-metal.
Every atom of an element will have orbitals in which electrons are found. These orbitals are known as energy level.
A molecule is defined as the smallest particle present in a substance or atom.
A metallic bond is formed due to mobile valence electrons shared by positive nuclei in a metallic crystal.
Thus, we can conclude that given statements are correctly matched as follows.
1). a chemical bond formed by the electrostatic attraction between ions - ionic bond
2). a chemical bond formed by two electrons that are shared between two atoms - covalent bond
3). the orbitals of an atom where electrons are found - energy level
4). the smallest particle of a covalently bonded substance - molecule
5). a bond characteristic of metals in which mobile valence electrons are shared among positive nuclei in the metallic crystal - metallic bond
Note: Above question is incomplete: Complete question is read as
<span>According the the arrhenius theory, which species does an acid produce in an aqueous solution?
</span>A) hydrogen ions B) hydroxyl ions C) Sodium ions D) Chloride ion
.....................................................................................................................
Correct answer for above question is A) Hydrogen ions
Reason:
According the Arrhenius theory of acid and base, acid generates hydrogen ions in aqueous medium, while bases generates hydroxyl ions in aqueous medium.
Example of Acid:
HCl(aq) → H+(aq) + Cl-(aq)
Example of Base:
NaOH(aq) → Na+(aq) + OH-(aq)
Answer:
[HF]₀ = 0.125M
Explanation:
NaOH + HF => NaF + H₂O
Adding 20ml of 0.200M NaOH into 25ml of HF solution neutralizes 0.004 mole of HF leaving 0.004 mole NaF in 0.045L with 0.001M H⁺ at pH = 3. This is 0.089M NaF and 0.001M HF remaining.
=> 45ml of solution with pH = 3 and contains 0.089M NaF from titration becomes a common ion problem.
HF ⇄ H⁺ + F⁻
C(eq) [HF] 10⁻³M 0.089M (<= soln after adding 20ml 0.200M NaOH)
Ka = [H⁺][F⁻]/[HF]₀ => [HF]₀ = [H⁺][F⁻]/Ka
[HF]₀ = (0.001)(0.089)/(7.1 x 10⁻⁴) M = 0.125M
