Answer:
A. 266g/mol
Explanation:
A colligative property of matter is freezing point depression. The formula is:
ΔT = i×Kf×m <em>(1)</em>
Where:
ΔT is change in temperature (0°C - -0,14°C = 0,14°C)i is Van't Hoff factor (1 for a nonelectrolyte dissolved in water), kf is freezing point molar constant of solvent (1,86°Cm⁻¹) and m is molality of the solution (moles of solute per kg of solution). The mass of the solution is 816,0g
Replacing in (1):
0,14°C = 1×1,86°Cm⁻¹× mol Solute / 0,816kg
<em>0,0614 = mol of solute</em>.
As molar mass is defined as grams per mole of substance and the compound weights 16,0g:
16,0g / 0,0614 mol = 261 g/mol ≈ <em>A. 266g/mol</em>
I hope it helps!
Answer:
What is most widely accepted today is the giant-impact theory. It proposes that the Moon formed during a collision between the Earth and another small planet, about the size of Mars. The debris from this impact collected in an orbit around Earth to form the Moon.
Explanation:
The correct answer for the given question above would be option A. The compound that would most likely be found in a deposit of natural gas is CH4 or METHANE. Methane is the main constituent of natural gas. It is<span> a colorless, odorless gas with a wide distribution in nature. Hope this answers your question.</span>
Answer:
6.25% of the original amount
Explanation:
half-life means that half is gone for every certain period of time. Because the half life is 1 month, only half of the 'radionulide' is left every month.
after 1 month= 50%
after 2 months= 25%
after 3 months= 12.5%
after 4 months= 6.25%
Missing question: 0,535 gram of KIO₃ dissolved in 250 mL of de-ionized water to <span>make primary standard solution.
m(</span>KIO₃) = 0,535 g.
V(KIO₃) = 250 mL ÷ 1000 mL/L = 0,25 L.
n(KIO₃) = m(KIO₃) ÷ M(KIO₃).
n(KIO₃) = 0,535 g ÷ 214 g/mol.
n(KIO₃) = 0,0025 mol.
c(KIO₃) = n(KIO₃) ÷ V(KIO₃).
c(KIO₃) = 0,0025 mol ÷ 0,25 L.
c(KIO₃) = 0,01 mol/L = 0,01 M.
