Answer:
n = 4, l = 2
Explanation:
The number 4 in 4d is the principal quantum number (n).
The letter d in 4d tells us that we have a d orbital, as determined by the <em>secondary quantum number (l</em>).
The quantum number l tells us the shape of the orbital.
l = 0 s orbital
l = 1 p orbital
l = 2 d orbital
Answer:
The concentration of this solution in units of pounds per gallon is 
Explanation:
Units of measurement are established models for measuring different quantities. The conversion of units is the transformation of a quantity, expressed in a certain unit of measure, into an equivalent one, which may or may not be of the same system of units.
In this case, the conversion of units is carried out knowing that 1 μg are equal to 2.205*10⁻⁹ Lb and 1 mL equals 0.00022 Gallons. So

If 1 μg equals 2.205*10⁻⁹ lb, 2.77 μg how many lb equals?

lb=6.10785*10⁻⁹
So, 2.77 μg= 6.10785*10⁻⁹ lb
Then:

You get:

<u><em>The concentration of this solution in units of pounds per gallon is </em></u>
<u><em></em></u>
Answer:
Molecular formula
Explanation:
Molecular formula in the first place is required to understand which compound we have. We then should refer to the periodic table and find the molecular weight for each atom. Adding individual molecular weights together would yield the molar mass of a compound.
Then, dividing the total molar mass of a specific atom by the molar mass of a compound and converting into percentage will provide us with the percentage of that specific atom.
E. g., calculate the percent composition of water:
- molecular formula is
; - calculate its molar mass: [tex]M = 2M_H + M_O = 2\cdot 1.00784 g/mol + 16.00 g/mol = 18.016 g/mol;
- find the percentage of hydrogen: [tex]\omega_H = \frac{2\cdot 1.00784 g/mol}{18.016 g/mol}\cdot 100 \% = 11.19 %;
- find the percentage of oxygen: [tex]\omega_O = \frac{16.00 g/mol}{18.016 g/mol}\cdot 100 \% = 88.81 %.
Answer:
The molarity is 0.56
Explanation:
In a mixture, the chemical present in the greatest amount is called a solvent, while the other components are called solutes. Then, the molarity or molar concentration is the number of moles of solute per liter of solution.
In other words, molarity is the number of moles of solute that are dissolved in a given volume.
The Molarity of a solution is determined by:

Molarity is expressed in units (
).
Then you must know the number of moles of Cu(NO₂)₂. For that it is necessary to know the molar mass. Being:
-
Cu: 63.54 g/mol
- N: 14 g/mol
- O: 16 g/mol
the molar mass of Cu(NO₂)₂ is:
Cu(NO₂)₂= 63.54 g/mol + 2*(14 g/mol + 2* 16 g/mol)= 155.54 g/mol
Now the following rule of three applies: if 155.54 g are in 1 mole of the compound, 225 g in how many moles are they?

moles= 1.45
So you know:
- number of moles of solute= 1.45 moles
- volume=2.59 L
Replacing in the definition of molarity:

Molarity= 0.56
<u><em>The molarity is 0.56</em></u>
<u><em></em></u>
Answer:
325mg of Aspririn
Explanation:
First you should note the information that the problem gives you:
- The bottle of Aspirin has 5gr (grains)
- 1gr(grain) = 65mg (miligrams)
Also, the problem is asking about how many aspirin are in 5 gr (grains), so you should use a conversion factor, as follows:
-First you should put the quantity you need to convert:

-Then you write the denominator of the conversion factor that must have the same units that you want to convert, in this case gr:

-Then you write the numerator with the units that you want to obtain and the numerical equivalence between the units, in this case:

-Finally you multiply numerators and divide by denominators:
