Answer is: a lower freezing point has solution of K₂SO₄.
Change in freezing
point from pure solvent to solution: ΔT =i · Kf · b.<span>
Kf - molal freezing-point depression constant for water is 1.86°C/m.
b - molality, moles of solute per
kilogram of solvent.
i - </span>Van't
Hoff factor.<span>
b(K</span>₂SO₄<span>) = 0.35 m.
</span>b(KCl) = 0.5 m.
i(K₂SO₄) = 3.
i(KCl) = 2.
ΔT(K₂SO₄) = 3 · 0.35 m · 1.86°C/m.
ΔT(K₂SO₄) = 1.953°C.
ΔT(KCl) = 2 · 0.5 m · 1.86°C/m.
ΔT(KCl) = 1.86°C.
We can solve this without a concrete formula through dimensional analysis. This works by manipulating the units such that you end up with the unit of the final answer. Manipulate them by cancelling units that appear both in the numerator and denominator side. As a result, we must be left with the units of g. The current in A or amperes is equivalent to amount of Coulombs per second. Since this involves Coulombs, we will use the Faraday's constant which is 96,500 C/mol electron. The reaction is:
Cr³⁺(aq) + 3e⁻ --> Cr(s)
This means that for every 3 moles of electron transferred, 1 mole of Chromium metal is plated. The molar mass of Cr: 52 g/mol. The solution is as follows:
Mass of Chromium metal = (8 C/s)(60 s/1 min)(160 min)(1 mol e⁻/96,500 C)(1 mol Cr/3 mol e)(52 g/mol)
<em>Mass of Chromium metal = 13.79 g</em>
Answer:
ν = 7.04 × 10¹³ s⁻¹
λ = 426 nm
It falls in the visible range
Explanation:
The relation between the energy of the radiation and its frequency is given by Planck-Einstein equation:
E = h × ν
where,
E is the energy
h is the Planck constant (6.63 × 10⁻³⁴ J.s)
ν is the frequency
Then, we can find frequency,
Frequency and wavelength are related through the following equation:
c = λ × ν
where,
c is the speed of light (3.00 × 10⁸ m/s)
λ is the wavelength
A 426 nm wavelength falls in the visible range (≈380-740 nm)
<h3>
Answer:</h3>
a) LiClO4 - Strong electrolyte
b) HClO -Weak electrolyte
c) CH3CH2CH2OH - Non-electrolyte
d) HClO3 - Strong electrolyte
e) CuSO4 -strong electrolyte
f) C12H22O11-Non-electrolyte
<h3>
Explanation:</h3>
- An electrolyte is a substance in an aqueous or molten form which is decomposed by passing an electric current through it. Electrolytes ionize to ions which are responsible for the conduction of electric charge.
- Non-electrolytes are substances that do not ionize into cations and anions and thus do not conduct. They include molecular compounds such as gases.
- Electrolytes may be weak or strong depending on the level of ionization.
- Weak electrolytes are those that undergo partial ionization while strong electrolytes completely ionize.
<span>30.%
Determine the molar mass of NH3 and NO
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Atomic weight oxygen = 15.999
Molar mass NH3 = 14.0067 + 3 * 1.00794 = 17.03052 g/mol
Molar mass NO = 14.0067 + 15.999 = 30.0057 g/mol
Moles NH3 = 8.5 / 17.03052 = 0.499103962 mol
Moles NO = 4.5 / 30.0057 = 0.149971505 mol
Looking at the balanced equation, for every mole of NH3 consumed, you should get one mole of NO. So if we had 100% yield, we should have 0.499103962 moles of NO. But we don't. The percent yield is a simple matter of division by what we did get by what we should get. So
0.149971505 / 0.499103962 = 0.300481497 = 30.0481497%
Rounding to 2 significant figures gives 30.% yield.</span>
