Answer is: molar mass of xylene 106,18 g/mol.
m(xylene) = 7,94 g.
m(cyclohexane) = 132,5 g.
T (solution) = - 4,9 °C.
Tf(cyclohexane) = 6,5 °C, frezing point.
Kf(cyclohexane) = 20,2 K·kg/mol; cryoscopic constant.
ΔT(solution) = 6,5°C - (-4,9°C) = 11,4°C = 11,4 K.
M(xylene) = Kf · m(xylene) ÷ m(cyclohexane) · ΔT(solution).
M(xylene) = 20,2 K·kg/mol · 7,94 g ÷ 0,1325 kg · 11,4 K.
M(xylene) = 106,18 g/mol.
Answer:
A
Explanation:
i did it before and got it right
Answer:
The [H⁺] for this soluton is 2*10⁻³ M
Explanation:
pH, short for Hydrogen Potential and pOH, or OH potential, are parameters used to measure the degree of acidity or alkalinity of substances.
The values that compose them vary from 0 to 14 and the pH value can be directly related to that of pOH by means of:
pH + pOH= 14
In this case, pOH=11.30, so
pH + 11.30= 14
Solving:
pH= 14 - 11.30
pH= 2.7
Mathematically the pH is the negative logarithm of the molar concentration of the hydrogen or proton ions (H⁺) or hydronium ions (H₃O):
´pH= - log [H⁺] = -log [H₃O]
Being pH=2.7:
2.7= - log [H⁺]
[H⁺]= 10⁻² ⁷
[H⁺]=1.995*10⁻³ M≅ 2*10⁻³ M
<u><em>The [H⁺] for this soluton is 2*10⁻³ M</em></u>
Answer: 2.04L
Explanation:
coldest temperature = -10°C
mass of solvent = 6.50kg
freezing point depression = kb*m
Where kb = molar freezing point depression constant, 1.86
10 = 1.86 * molality of ethylene glycol
10 = 1.86 * moles of ethylene glycol/mass of solvent
10 = 1.86 * moles of ethylene glycol/6.5
10*6.5 = 1.86 * moles of ethylene glycol
Moles of ethylene glycol = 65/1.86
Moles of ethylene glycol = 36.11
36.11 mol * 62.1 g/mol = 2242.43g = 2.24kg
1 L = 1000 mL x 1.11 g/mL = 1100 g = 1.1 kg
2.24 kg / 1.10 kg/L = 2.04 L
