D. Liquid Nitrogen is much colder than Water.
Answer:
pH = 11.05
Explanation:
It is possible to answer this question using Henderson-Hasselbalch formula:
pH = pka + log₁₀ [A] / [HA⁺]
Where A in this case is weak base (dimethylamine) and conjugate acid (HA⁺) is dimethylamine hydrochloride.
As Ka= Kw / Kb = 1x10⁻¹⁴ / 7.4x10⁻⁴ = 1.35x10⁻¹¹ And pKa is -log Ka = <em>10.87 </em> pH of the solution is:
pH = 10.87 + log₁₀ [0.600] / [0.400]
<em>pH = 11.05</em>
<em></em>
I hope it helps!
Answer:
A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.
Explanation:
Hello.
In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:
As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.
Best regards.
If the hydrate gets too hot it could start splattering and cause a loss of sample.
Answer:
68.18%
Explanation:
The question asking for the percentage of sugar present in milk bar chocolate. To find the percentage of a certain molecule, you have to divide the mass of the molecule with the total mass of the product. The calculation will be:
sugar percentage = sugar weight / milk bar chocolate weight * 100%
sugar percentage = 7.5g / 11g * 100%= 68.18%
