Answer:
6.82g
0.59moles
Explanation:
1. What is the mass sample of 0.0500 moles of zinc chloride ?
Given parameters:
Number of moles ZnCl₂ = 0.05moles
Unknown:
Mass of the sample = ?
Solution:
To find the mass of a substance using the number of moles, it would be pertinent to understand what mole is.
A mole is a substance that contains the avogadro's number of particles.
It relates to the mass using the expression below;
Mass of a substance = number of moles x molar mass
Molar mass of ZnCl₂;
Atomic mass of Zn = 65.4g/mol
Cl = 35.5g/mol
Molar mass = 65.4 + 2(35.5) = 136.4g/mole
Mass of a substance = 0.05 x 136.4 = 6.82g
2. How many moles of potassium sulfide are in a 65.50g sample?
Given parameters:
Mass of K₂S = 65.5g
Unknown:
Number of moles = ?
Solution:
The number of moles of any substance is related to mass using the expression below;
Number of moles =
Molar mass of K₂S = 2(39) + 32 = 110g/mol
Number of moles = = 0.59moles
Answer:
55.9 g KCl.
Explanation:
Hello there!
In this case, according to the definition of molality for the 0.500-molar solution, we need to divide the moles of solute (potassium chloride) over the kilograms of solvent as shown below:
Thus, solving for the moles of solute, we obtain:
Since the density of water is 1 kg/L, we obtain the following moles:
Next, since the molar mass of KCl is 74.5513 g/mol, the mass would be:
Regards!
Answer:
0.56 liters
Explanation:
First we <u>convert 0.80 grams of O₂ into moles</u>, using its molar mass:
- 0.80 g ÷ 32 g/mol = 0.025 mol
At STP, 1 mol of any given mass occupies 22.4 L. With that information in mind we <u>calculate the volume that 0.025 moles of O₂ gas would occupy</u>:
- 0.025 mol * 22.4 L/mol = 0.56 L
Thus the answer is 0.56 liters.
covalent bond is firmed between two atoms