Explanation:
Because molarity is classified as moles of solute per liter of water, dilution of the water may result in a reduction of its concentration.
Therefore, because the amount of moles of solute has to be constant for dilution, you will use the molarity and volume of that same target solution to calculate how many moles of solute will be present in the sample of the stock solution that you dilute.
c =
⇒ n
=
c
⋅ V
= 0.250 M ⋅ 6.00 L =
1.5 moles HCl
Now all you have to do is figure out what volume of 6.0 M stock solution will contain 1.5 moles of hydrochloric acid
c =
V =
= =
0.25 L
Expressed in milliliters, the answer will be
→ rounded to two sig figs
Approximately .
The relative atomic weight of an element is a weighted average of the atomic mass for all its isotopes. It accounts for the atomic mass for each isotope, as well the relative abundance of each.
The question provides no detailed data on the relative mass for each isotope atom. Each nucleon- proton or neutron- has a mass of approximately . The mass number of an atom gives the total number of nucleons it contains. The mass number can, therefore, serve as a numerical estimator for the relative atomic mass of an isotope. That is:
- Copper-63 has mass number 63 and a relative atomic mass of approximately ;
- Copper-65 has mass number 65 and a relative atomic mass of approximately
Copper-63 has an abundance of 69.17% relative to all copper atoms. Similarly, copper-65 has a relative abundance of 30.83%. Therefore, one would expect to find 6,917 copper-63 atoms and 3,083 copper-65 atoms in a sample of 10,000 copper atoms. Similarly, 10,000 <em>moles</em> or 10,000 × (6.02 × 10²³) copper atoms would contain 6,917 <em>moles</em> of copper-63 atoms and 3,083 <em>moles</em> of copper-65 atoms.
10,000 moles of copper atoms would have a mass of approximately
.
Each mole of copper atoms would thus have a mass of approximately
.
Combining the two previous steps would give:
,
which essentially multiplies the relative atomic mass by their relative abundance, and takes the sum of the products.
The relative atomic mass of an element is measured in grams per mole. One mole of copper atoms have a mass of 63.62 grams. Copper thus has a relative atomic mass of .
Hey there!
The answer is D, Salinity.
Salinity is the concentration of salt in water. Ocean water often has high salinity and this can contribute to things like upwelling and water density- but these all start from salinity.
Hope this helps!
Answer:- D) particles .
Solution:- There are 1.53 moles of the compound are given and it asks to calculate the number of particles.
To calculate the number of particles we multiply the moles with Avogadro number.
=
So, the D is the right choice.