pH=6.98
Explanation:
This is a very interesting question because it tests your understanding of what it means to have a dynamic equilibrium going on in solution.
As you know, pure water undergoes self-ionization to form hydronium ions, H3O+, and hydroxide anions, OH−.
2H2O(l]⇌H3O+(aq]+OH−(aq]→ very important!
At room temperature, the value of water's ionization constant, KW, is equal to 10−14. This means that you have
KW=[H3O+]⋅[OH−]=10−14
Since the concentrations of hydronium and hydroxide ions are equal for pure water, you will have
[H3O+]=√10−14=10−7M
The pH of pure water will thus be
pH=−log([H3O+])
pH=−log(10−7)=7
Now, let's assume that you're working with a 1.0-L solution of pure water and you add some 10
Answer:
(C) Acetylene (ethyne) can be converted to the acetylide anion by treating with a strong base such as CH₃Li.
Explanation:
Acetylene (C₂H₂) can be converted to the acetylide anion (C₂⁻²) when treated with a base because it will donate protons (2H⁺). So it will be a neutralization reaction. NaNH₂ and NaOH are strong bases because they are good electrons donators ( NaNH₂ has pair of electrons on N, and NaOH has the group OH⁻), but CH₃Li has no pair of electrons to donate, so it's not a strong base.
Answer:
25 grams
Explanation:
You strat off with 400 grams of your substance. By day 14, half has dcayed and you only have 200 grams left. By day 28, there are 100 grams of the substance. On day 42, there are 50 grams left. Finally, on day 56, the substance has been through four half-lives and 25 grams remain.
Answer:
The water phase with the smallest temperature increase when adding 10 kcal of heat is solid ice.
Explanation:
The rest of the statements are incorrect. The density of ice is lower than the density of water. The heat capacity of solid ice is greater almost twice the heat capacity of the liquid water. The heat capacity of vapors is less than heat capacity of liquid.
