Answer:
Between all other stars, I would say the answer is W.
Anyone correct me if I'm wrong. :)
Explanation:
Answer:
1. An apple is something that has matter.
2. Light does not have matter. It neither has mass or takes up and space.
3. Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes cause a substance to change into an entirely substance with a new chemical formula. Chemical changes are also known as chemical reactions.
4. A chemical reaction is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change. Absolute confirmation of a chemical change can only be validated by chemical analysis of the products!
5. A precipitate is a solid that forms out of solution.
6. In simple terms, the endothermic reactions absorb energy from the surrounding that is in the form of heat. On the other hand, an exothermic reaction releases energy into the surrounding of the system.
Explanation:
Matter is anything that has mass and takes up volume.
In Nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides.
Answer:
a. pH = 7.0
b. pH = 12.52
c. pH = 12.70
d. pH = 12.78
Explanation:
a. Deionized water has the [H⁺] of pure water = 1x10⁻⁷ (Kw = 1x10⁻¹⁴ = [H⁺][OH⁻] - [H⁺] = [OH⁻ -)
pH = -log[H⁺] = 7
b. Moles NaOH = 5x10⁻³L * (0.10mol / L) = 5x10⁻⁴moles OH⁻ / 0.015L = 0.0333M = [OH⁻]
<em>-Total volume = 10mL+5mL = 15mL = 0.015L</em>
pOH = -log[OH⁻] = 1.48
pH = 14-pOH
pH = 12.52
c. Moles NaOH = 0.010L * (0.10mol / L) = 1x10⁻³moles OH⁻ / 0.020L = 0.0500M = [OH⁻]
<em>-Total volume = 10mL+10mL = 20mL = 0.020L</em>
pOH = -log[OH⁻] = 1.30
pH = 14-pOH
pH = 12.70
d. Moles NaOH = 0.015L * (0.10mol / L) = 1.5x10⁻³moles OH⁻ / 0.025L = 0.060M = [OH⁻]
<em>-Total volume = 10mL+15mL = 25mL = 0.025L</em>
pOH = -log[OH⁻] = 1.22
pH = 14-pOH
pH = 12.78
I think it is Molar masses of compounds involved or Oxidation numbers, but you can choose one of them. Or you can think about the question carefully.