The mass number of an isotope can be expressed <span>by simply writing the name of the element or symbol followed by a hyphen and the mass number.
Example:
Carbon-13, Carbon-14
Oxygen-17
Uranium-235
</span>
Answer:
Mark me brainliest
Explanation:
Standards help avoid confusion and ambiguity when taking measurements. For example, a meter will always be the same length, no matter who is taking the measurement or where it is being taken.
Answer:
Energy and how it can change forms. Kinetic, potential, and chemical energy.
Answer:
mass is 4.57 g
Explanation:
Ca(OH)₂ solution consists of Ca(OH)₂ solute molecules and solvent and we are asked to find the mass of Ca(OH)₂ in the solution
number of moles of Ca(OH)₂ is - 0.0787 mol
molar mass of Ca(OH)₂ is - 58.093 g/mol
we can use the following equation
number of moles = mass of Ca(OH)₂ / molar mass of Ca(OH)₂
rearranging the equation
mass of Ca(OH)₂ = number of moles x molar mass
mass = 0.0787 mol x 58.093 g/mol = 4.57 g
mass of Ca(OH)₂ is 4.57 g
Complete Question:
A chemist prepares a solution of iron chloride by measuring out 0.10 g of FeCl2 into a 50. mL volumetric flask and filling to the mark with distilled water. Calculate the molarity of anions in the chemist's solution.
Answer:
[Fe+] = 0.0156 M
[Cl-] = 0.0316 M
Explanation:
The molar mass of iron chloride is 126.75 g/mol, thus, the number of moles presented in 0.10 g of it is:
n = mass/molar mass
n = 0.10/126.75
n = 7.89x10⁻⁴ mol
In a solution, it will dissociate to form:
FeCl2 -> Fe+ + 2Cl-
So, the stoichiometry is 1:1:2, and the number of moles of the ions formed are:
nFe+ = 7.89x10⁻⁴ mol
nCl- = 2*7.89x10⁻⁴ = 1.58x10⁻³ mol
The molarity is the number of moles divided by the solution volume, in L (50.0 mL = 0.05 L):
[Fe+] = 7.89x10⁻⁴/0.05 = 0.0156 M
[Cl-] = 1.58x10⁻³/0.05 = 0.0316 M