Answer is: Kb for methylamine is 4.37·10⁻⁴.<span>
Chemical reaction: CH</span>₃NH₂ + H₂O → CH₃NH₃⁺ + OH⁻.
c(CH₃NH₂) = 0.253 M.
α = 4.07% ÷ 100% = 0.0407.
[CH₃NH₃⁺] = [OH⁻] = c(CH₃NH₂) · α.
[CH₃NH₃⁺] = [OH⁻] = 0.253 M · 0.0407.
[CH₃NH₃⁺] = [OH⁻] = 0.0103 M.
[CH₃NH₂] = 0.253 M - 0.0103 M.
[CH₃NH₂] = 0.2427 M.
Kb = [CH₃NH₃⁺] · [OH⁻] / [CH₃NH₂].
Kb = (0.0103 M)² / 0.2427 M.
Kb = 4.37·10⁻⁴.
Answer is: 48,25 torr.
Raoult's Law: p = x(solv) · p(solv)
p - <span>vapour pressure of a solution.
</span>x(solv) - <span>mole fraction of the solvent.
</span>p(solv) - <span>vapour pressure of the pure solvent.
</span>n(ethanol) = 950g ÷ 46,07g/mol = 20,62 mol.
x(solv) = moles of solvent ÷ total number of moles
x(solv) = 20,62 ÷ 21,77 = 0,965.
p = 0,965 ·50,0 torr = 48,25 torr.
Answer:
A sample of 830 kg would contain 830000000 mg
Explanation:
Answer:
<h2>1. Ionic compound-

</h2><h2>2. Polar molecular compound-

</h2>
Explanation:
Mg is a metal that has 12 atomic numbers and thus its electronic configuration is
. The outer most shell of this element has 2 electrons so it loses 2 electrons and thus form
ions. Br is a nonmetal and has 35 atomic number so its electronic configuration is
. Since its outermost shell has 7 electrons so it can accept one electron and thus forms
. So magnesium ion and bromide ion combine and forms an ionic compound
.
P is also a nonmetal and combine with Br with covalent bond and due to electronegativity differences form polar covalent compound such as
.
Answer:
4.8 %
Explanation:
We are asked the concentration in % by mass, given the molarity of the solution and its density.
0.8 molar solution means that we have 0.80 moles of acetic acid in 1 liter of solution. If we convert the moles of acetic acid to grams, and the 1 liter solution to grams, since we are given the density of solution, we will have the values necessary to calculate the % by mass:
MW acetic acid = 60.0 g/mol
mass acetic acid (the solute) = 0.80 mol x 60 g / mol = 48.00 g
mass of solution = 1000 cm³ x 1.010 g/ cm³ (1l= 1000 cm³)
= 1010 g
% (by mass) = 48.00 g/ 1010 g x 100 = 4.8 %