First calculate for the molar mass of the given formula unit, CaCO₃. This can be done by adding up the product when the number of atom is multiplied to its individual molar mass as shown below.
molar mass of CaCO₃ = (1 mol Ca)(40 g Ca/mol Ca) + (1 mol C)(12 g of C/1 mol of C) + (3 mols of O)(16 g O/1 mol O) = 100 g/mol of CaCO₃
Then, divide the given amount of substance by the calculated molar mass.
number of moles = (20 g)(1 mol of CaCO₃/100 g)
number of moles = 0.2 moles of CaCO₃
<em>Answer: 0.2 moles</em>
Answer:
- What distinguish a solution in general from an aqueous solution is the solvent. A solution in general may contain any solvent, which may be solid, liquid or gas, while an aqueous solution is formed with water as solvent.
Explanation:
A solution in general is a homogeneous mixture in which a substance, named solute, is dissolved, in other substance, name solvent.
Solutions may be in solid, liquid or gas state. There are many kind of solvents. Usually, in a lab you work with liquid solutions. Some liquid solvents are: ethanol, glycerin, hexane, benzene, and water, among many others.
Aqueous solution is a solution where the solvent is water. Of course, the solute may be any one: NaCl, sugar, ethanol, an acid, a base, a salt.
What distinguish a solution in general and an aqueous solution is the solvent.
Answer:
The concentration of the copper sulfate solution is 83 mM.
Explanation:
The absorbance of a copper sulfate solution can be calculated using Beer-Lambert Law:
A = ε . c . <em>l</em>
where
ε is the extinction coefficient of copper sulfate (ε = 12 M⁻¹.cm⁻¹)
c is its molar concentration (what we are looking for)
l is the pathlength (0.50 cm)
We can use this expression to find the molarity of this solution:
Answer: I believe the answer you are looking for is 0.02180
