Answer:
The answer to your question is V₁ = 12.5 ml
Explanation:
Data
Volume = V₁?
[NaOH] = C₁ = 4.0 M
Volume 2 = V₂ = 100 ml
[NaOH] = C₂ = 0.5 M
Formula of dilution
V₁C₁ = V₂C₂
Solve for V₁ (original solution)
V₁ = 
Substitution
V₁ = 
Simplification
V₁ = 
Result
V₁ = 12.5 ml
For one complete orbit of the earth around the sun
Answer:
Indeed, the two samples should contain about the same number of gas particles. However, the molar mass of 
is larger than that of 
(by a factor of about 
.) Therefore, the mass of the sample is significantly larger than that of the sample.
Explanation:
The and the sample here are under the same pressure and temperature, and have the same volume. Indeed, if both gases are ideal, then by Avogadro's Law, the two samples would contain the same number of gas particles ( and molecules, respectively.) That is:
.
Note that the mass of a gas 
is different from the number of gas particles 
in it. In particular, if all particles in this gas have a molar mass of 
, then:
.
In other words,
.
.
The ratio between the mass of the and that of the sample would be:
.
Since by Avogadro's Law:
.
Look up relative atomic mass data on a modern periodic table:
Therefore:
.
.
Verify whether 
:
- Left-hand side:
. - Right-hand side:
.
Note that the mass of the sample comes with only two significant figures. The two sides of this equations would indeed be equal if both values are rounded to two significant figures.
Answer:
Phosphorus has a low melting point because the intramolecular forces holding it together is London Dispersion Forces.
Explanation:
London Dispersion Forces (LDF) are the weakest intramolecular forces. You don't need to break the covalent bonds, but rather the Van Der Waals' Forces. If LDF are the weakest forces, then the melting point is low.
Answer:
At temperatures below −78 °C, carbon dioxide changes directly from a gas to a white solid called dry ice through a process called deposition.
