What is the concentration (in M) of a 225ml potassium sulfate solution that contains 4.15g of potassium?
1 answer:
The concentration of solution in M or mol/L can be calculated using the following formula:
.... (1)
Here, n is number of moles and V is volume of solution in L.
The molecular formula of potassium sulfate is thus, there are 2 moles of potassium in 1 mol of potassium sulfate.
1 mol of potassium will be there in 0.5 mol of potassium sulfate.
Mass of potassium is 4.15 g, molar mass is 39.1 g/mol.
Number of moles can be calculated as follows:
Here, m is mass and M is molar mass
Putting the values,
Thus, number of moles of will be
.
The volume of solution is 225 mL, converting this into L,
Thus,
Putting the values in equation (1),
Therefore, concentration of potassium sulfate solution is 0.236 M.
You might be interested in
The question is missing the molecules in which the integration ratio of 2:3 will be observed. The complete question is given in the attachment.
Answer:
Molecule (a), (c), and (f) will show two peaks with the integration ratio of 2:3 in their 1H NMR spectrum
Explanation:
In the 1H NMR spectrum, the peak area is dependent on the number of hydrogen in a specific chemical environment. Hence, the ratio of the integration of these signals provides us with the relative number of hydrogen in two peaks. This rationale is used for the assignment of molecules that will give 2:3 integration ratio in the given problem.
- Molecule (a) have two CH₂ and three CH₃ groups. Hence, it will give two peaks and their integration ratio becomes 2:3 (Answer)
- Molecule (b) contains three chemical environments for its hydrogen atoms
- Molecule (c) have a single CH₂ and CH₃ group giving integration ratio of 2:3 (Answer)
- Molecule (d) will give two peaks but their ratio will be 1:3 because of two hydrogens of CH₂ and six hydrogens from two CH₃ groups
- Molecule (e) have three CH and three CH₃ groups, so their ratio will become 1:3
- Molecule (f) contains four CH and two CH₃ groups, giving two peaks. So, the integration ratio of their peaks is 2:3 (Answer)
- Molecules
- (g)
- and
- (h)
- both have two CH and two CH₃ groups giving two peaks with the integration ratio of 1:3
Answer:
Conversion factor;
Molar mass;
Avogadro's constant and molar mass
Explanation:
- Firstly, an intermediate step is to define the conversion factor that will be then used in a conversion technique called dimensional analysis in order to convert from one unit to another. An example of a conversion factor would be, for example, 1 L = 1000 mL, which can be manipulated as a fraction, either
or
;
- Secondly, in order to convert mass to moles, we need to know the molar mass of a compound which has a units of g/mol (that is, it shows how many grams we have per 1 mole of substance.
- Thirdly, Avogadro's constant,
tells us that there is
number of molecules or atoms in 1 mole of substance. We need two conversion factors to convert the number of molecules to a mass: firstly, we need to convert the number of molecules into the number of moles using Avogadro's constant and then we need to use the molar mass to convert the moles obtained into mass.