The list of the answer choices is missing.
I did some research in internet and found this is the complete question, including the answer choices:
<span>Which is true about dissolving a polar substance in water?
A. The solvent particles are all nonpolar molecules.
B. The solute particles are carried into the solution.
C. The solute particles have no attraction for the solvent molecules.
D. The solute particles are very different from the solvent molecules.
The right answer is the option B. The solute particles are carried into the solution.
Let's review each choice.</span><span>
A. The solvent particles are all nonpolar molecules.
False
The solvent is water, and water is a polar solvent. This is, due to the difference in electronegativity of the atoms of H and O, the bonds form dipoles (the O atoms have a partial negative charge and the H atoms have a partial positive charge). And, since the molecule is not symmetrical those dipoles yield a polar molecule.
B. The solute particles are carried into the solution.
That is true: being the solute a polar substance the negative endings of the solute will be attracted by the partially positive H of water, and the positive endings of the solute will be attracted by the partially negative O of water, meaning that the molecules of water will surround the particles of solute.
C. The solute particles have no attraction for the solvent molecules.
As per the explanations given above this is false.
D. The solute particles are very different from the solvent molecules.
False, because the solute particles are similar to the solvente molecules in that both of them are polar.
</span>
a. 627.1 m/s
b. the rate of effusion of ethane = 1.7 faster than hexane
<h3>Further explanation
</h3>
Given
T = 200 + 273 = 473 K
Required
a. the gas speed
b. The rate of effusion comparison
Solution
a.
Average velocities of gases can be expressed as root-mean-square averages. (V rms)
R = gas constant, T = temperature, Mm = molar mass of the gas particles
From the question
R = 8,314 J / mol K
T = temperature
Mm = molar mass, kg / mol
Molar mass of Ethane = 30 g/mol = 0.03 kg/mol
b. the effusion rates of two gases = the square root of the inverse of their molar masses:
M₁ = molar mass ethane =30
M₂ = molar mass hexane = 86
the rate of effusion of ethane = 1.7 faster than hexane
Answer: 159 grams
Explanation:
Copper (ii) oxide has the chemical formula CuO.
Now given that:
Mass of CuO in grams = ? (let unknown value be Z)
Number of moles = 2.00 moles
Molar mass of CuO = ?
For the molar mass of CuO: Atomic mass of Copper = 63.5g ; Oxygen = 16g
= 63.5g + 16g
= 79.5 g/mol
Apply the formula:
Number of molecules = (mass in grams/molar mass)
2.00 moles = (Z / 79.5 g/mol)
Z = 79.5 g/mol x 2.00 moles
Z = 159g
Thus, there are 159 grams in 2.00 moles of copper (ii) oxide
Answer:
The reasons can be :
There are impurities in substances
Answer is: name of the compound Re₂O₅ is rhenium(V) oxide.
In this chemical compound atom of rhenium has oxidation number +5 and atom oxygen has oxidation number -2, chemical compound rhenium(V)-oxide has neutral charge (2·(+5) + 5·(-2) = 0).
Roman five is for valence of rhenium in this compound.