Boiling-point elevation is a colligative property.
That means, the the boiling-point elevation depends on the molar content (fraction) of solute.
The dependency is ΔTb = Kb*m
Where ΔTb is the elevation in the boiling point, kb is the boiling constant, and m is the molality.
A solution of 6.00 g of Ca(NO3) in 30.0 g of water has 4 times the molal concentration of a solution of 3.00 g of Ca(NO3)2 in 60.0 g of water.:
(6.00g/molar mass) / 0.030kg = 200 /molar mass
(3.00g/molar mass) / 0.060kg = 50/molar mass
=> 200 / 50 = 4.
Then, given the direct proportion of the elevation of the boiling point with the molal concentration, the solution of 6.00 g of CaNO3 in 30 g of water will exhibit a greater boiling point elevation.
Or, what is the same, the solution with higher molality will have the higher boiling point.
Answer:
6 oxygen atoms
Explanation:
From the equation,
2Fe(OH)₃ → Fe₂O₃ + 3H₂O
From the reactant (left hand side) we have 2 moles of Fe(OH)₃ having (2 * 3 = 6) atoms of oxygen and decomposed to give Fe₂O₃ which contains 3 atoms of oxygen and 3 moles of water that also contains 3 atoms of oxygen.
Since the number of oxygen participating in the reaction is independent on the product (not a reversible reaction) then the total number of oxygen atoms participating in the reaction is 6
Isotopes are atoms of the same element that have different numbers of neutrons.
Answer:
0.252 milimoles
Explanation:
To convert mass of a substance to moles it is necessary to use the molar mass of the substance.
The formula of morphine is C₁₇H₁₉NO₃, thus, its molar mass is:
C: 17*12.01g/mol = 204.17g/mol
H: 19*1.01g/mol = 19.19g/mol
N: 1*14g/mol = 14g/mol
O: 3*16g/mol = 48g/mol.
204.17 + 19.19 + 14 + 16 = <em>285.36g/mol</em>
Thus, moles of 71.891 mg = 0.071891g:
0.071891g × (1mol / 285.36g) = 2.5193x10⁻⁴ moles
As 1 mole = 1000 milimoles:
2.5193x10⁻⁴ moles = <em>0.252 milimoles</em>
Answer: 150 grams
Explanation: m = V × ρ
= 15 milliliter × 10 gram/cubic centimeter
= 15 cubic centimeter × 10 gram/cubic centimeter
= 150 gram
