Answer:
680 g/m is the molar mass for the unknown, non electrolyte, compound.
Explanation:
Let's apply the formula for osmotic pressure
π = Molarity . R . T
T = T° absolute (in K)
R = Universal constant gases
π = Pressure
Molarity = mol/L
As units of R are L.atm/mol.K, we have to convert the mmHg to atm
760 mmHg is 1 atm
28.1 mmHg is (28.1 .1)/760 = 0.0369 atm
0.0369 atm = M . 0.082 L.atm/mol.K . 293K
(0.0369 atm / 0.082 mol.K/L.atm . 293K) = M
0.0015 mol/L = Molarity
This data means the mol of solute in 1L, but we have 100mL so
Molarity . volume = mol
0.0015 mol/L . 0.1L = 1.5x10⁻⁴ mole
The molar mass will be: 0.102g / 1.5x10⁻⁴ m = 680 g/m
Answer: 2 molecules of ammonia
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for the formation of ammonia is:
According to stoichiometry,
3 molecules of hydrogen combines with 1 molecule of nitrogen to give 2 molecules of ammonia.
When we have this balanced equation for a reaction:
Fe(OH)2(s) ↔ Fe+2 + 2OH-
when Fe(OH)2 give 1 mole of Fe+2 & 2 mol of OH-
so we can assume [Fe+2] = X and [OH-] = 2 X
when Ksp = [Fe+2][OH-]^2
and have Ksp = 4.87x10^-17
[Fe+2]= X
[OH-] = 2X
so by substitution
4.87x10^-17 = X*(2X)^2
∴X^3 = 4.8x10^-17 / 4
∴the molar solubility X = 2.3x10^-6 M
Answer:
20 electrons
A neutral atom with atomic number 20 will have 20 electrons.
The atomic number is, by definiton, the number of protons in an atom's nucleus but for a neutral atom it's also equal to the number of electrons. Each element has a different, unique number of protons that determines its identity.
Explanation:
To answer the question above, let us a basis of the 1000 mL or 1 L.
volume = (0.9928 g/mL)(1000mL) = 992.8 g
Then, determine the mass of the alcohol by multiplying the total mass by the decimal equivalent of 5%.
mass of alcohol = 0.05(992.8 g) = 49.64 g
Then, determine the number of moles of ethyl alcohol by dividing the mass of alcohol by the molar mass (46 g/mol).
n = 49.64 g/ (46 g/mol) = 1.08 mol
Then, divide the number of moles by the volume (our basis is 1 L)
molarity = 1.08 mol/ 1 L = 1.08 M
