How many moles are in 24.0 g KCl?
A. 3.22 mol
B. .32 mol
C. 0.322 mol
D. 32.2 mol
C
right
To find the number of moles in a given amount of a substance, you need to use the formula:
moles = mass / molar mass
In this case, the mass of KCl is given as 24.0 g.
To calculate the molar mass of KCl, you add together the atomic masses of potassium (K) and chlorine (Cl). The atomic mass of K is 39.10 g/mol, and the atomic mass of Cl is 35.45 g/mol.
So, the molar mass of KCl is:
Molar mass = (1 * atomic mass of K) + (1 * atomic mass of Cl)
= (1 * 39.10 g/mol) + (1 * 35.45 g/mol)
= 74.55 g/mol
Now, you can calculate the number of moles using the given mass and the molar mass:
moles = mass / molar mass
= 24.0 g / 74.55 g/mol
≈ 0.322 mol
Therefore, the correct answer is C. 0.322 mol.