Answer:
1.58x10⁻⁵
2.51x10⁻⁸
0.0126
63.10
Explanation:
Phenolphthalein acts like a weak acid, so in aqueous solution, it has an acid form HIn, and the conjugate base In-, and the pH of it can be calculated by the Handerson-Halsebach equation:
pH = pKa + log[In-]/[HIn]
pKa = -logKa, and Ka is the equilibrium constant of the dissociation of the acid. [X] is the concentrantion of X. Thus,
i) pH = 4.9
4.9 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = - 4.8
[In-]/[HIn] =
[In-]/[HIn] = 1.58x10⁻⁵
ii) pH = 2.1
2.1 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = -7.6
[In-]/[HIn] =
[In-]/[HIn] = 2.51x10⁻⁸
iii) pH = 7.8
7.8 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = -1.9
[In-]/[HIn] =
[In-]/[HIn] = 0.0126
iv) pH = 11.5
11.5 = 9.7 + log[In-]/[HIn]
log[In-]/[HIn] = 1.8
[In-]/[HIn] =
[In-]/[HIn] = 63.10
Absolute zero or 0 kelvin
<h3><u>Answer;</u></h3>
D. All the above
- Covalent compounds are always poor conductors of electricity while ionic compounds conduct electricity well when melted or dissolved.
- Covalent compounds can be solid, liquid or gas, but ionic compounds are solids.
- In covalent compounds the elements present are usually close together on the periodic table whereas in ionic compounds they are usually well separated.
<h3><u>Explanation;</u></h3>
- <u>Ionic compounds are compounds that are formed from strong electrostatic interactions between ions.</u> Ionic bonding occurs between a nonmetal, which acts as an electron acceptor, and a metal, which acts as an electron donor. The atoms involved in ionic bonding lose or gain electrons and form positively or negatively charged ions.
- <em><u>Ionic compound are good conductors of electricity both in molten and aqueous form,. while covalent compound are poor conductors of electricity.</u></em>
- <u>Covalent compounds on the other hand are compounds that have bonds where electrons are shared between atoms.</u> These types bonds mostly occur between nonmetals or between two atoms of the same element.
Answer:
When a sodium atom transfers an electron to a chlorine atom, forming a sodium cation (Na+) and a chloride anion (Cl-), both ions have complete valence shells, and are energetically more stable. The reaction is extremely exothermic, producing a bright yellow light and a great deal of heat energy.
Answer: the answer is a=10m/s^2 right
Explanation: it just make more since then the other answers .