Answer:
molar mass of methane CH4
= C + 4 H
= 12.0 + 4 x 1.008
= 12.0 + 4.032
= 16.042g/mol
7.31 x 10^25 molecules x 1 mole CH4 = 121.43 moles
6.02 x 10^23 CH4 molecules
121.43 moles CH4 are present.
Explanation:
not to certain if this is right or not.. but hope it helps!
Answer:
817.66 g/mol
Explanation:
The <em>freezing point change</em> can be calculated by the formula:
Where m is the molality of the solute in NO, Kf is the cryoscopic constant (in K·kg/mol), and i is 1 in this case (because the substance in non-dissociating).
We can <u>calculate Kf of NO</u> with the information given by the problem and the formula:
Where R is the universal gas constant (8.314 J·mol⁻¹·K⁻¹), M is the molar mass of NO (30 g/mol, or 0.03 kg/mol), T f is the freezing point of NO (in K), and ΔH is the heat of fusion.
- Kf = 8.314 J·mol⁻¹·K⁻¹ * 0.03 kg/mol * (109.16 K)² ÷ 2300 J/mol = 1.292 K·kg/mol
Now we calculate the molality of the solute in NO:
<em>Molality is equal to the moles of solute per kilogram of solvent</em>:
- 0.1370 m = moles solute/ 1 kg NO
- moles solute = 0.1370 moles
With the given mass of the solute we <u>can calculate the molar mass</u>:
- 112 g / 0.1370 moles = 817.66 g/mol
The mole fraction of a gaseous compound is equal to the ratio of the vapor pressure of the compound to the total pressure of the vessel. In this case, teh vapor pressure of tehe non-electrolyte is 760 - 745 = 15 mmHg. hence the mole fraction is 15 mm Hg / 760 mmHg equal to 0.0197
Compound monthly is correct
the answer is magnesium chloride. it is an ionic compound because Mg forms ionic bond to Cl by donating its valence electrons to two Cl atoms. :)