The
balanced half-reaction: Cr⁴⁺(aq)+ 4e⁻ →
Cr(s).
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Chromium(IV) cations gain four electrons and became solid chromium with neutral charge.
</span>Reduction is lowering oxidation number because element or ions gain electrons.
Oxidation reaction is increasing of oxidation number of element, because
element or ion lost electrons in chemical reaction.
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The correct answer is option 2. When Pt2+ is reduced it loses electrons, oxidizing it. The oxidation number is the charge of the atom. Adding an electron, decreases the net charge consequently the oxidation number.
Answer:
PNO₂ = 0.49 atm
PN₂O₄ = 0.45 atm
Explanation:
Let's begin with the equation of ideal gas, and derivate from it an equation that involves the density (ρ = m/V).
PV = nRT
n = m/M (m is the mass, and M the molar mass)
PxM = ρRT
ρ = PxM/RT
With the density of the gas mixture, we can calculate the average of molar mass (Mavg), with the constant of the gases R = 0.082 atm.L/mol.K, and T = 16 + 273 = 289 K
0.94Mavg = 63.9846
Mavg = 68.0687 g/mol
The molar mass of N is 14 g/mol and of O is 16 g/mol, than 
g/mol and 
g/mol. Calling y the molar fraction:
And,
So,
The partial pressure is the molar fraction multiplied by the total pressure so:
PNO₂ = 0.52x0.94 = 0.49 atm
PN₂O₄ = 0.48x0.94 = 0.45 atm
Answer:
42.5 g
Explanation:
Calculate the mass of the soft drink given the density and volume:
355 mL × 1.04 g/mL = 369.2 g
Now calculate the mass of sucrose given the percentage:
0.115 × 369.2 g = 42.46 g
Rounded to 3 significant figures, the mass is 42.5 g.
Answer:
E. CH₄ < CH₃Cl < CH₃OH < RbCl
Explanation:
The molecule with the stronger intermolecular forces will have the higher boiling point.
The order of strength of intermolecular forces (strongest first) is
- Ion-Ion
- Hydrogen bonding
- Dipole-dipole
- London dispersion
RbCl is a compound of a metal and a nonmetal. It is an ionic compound, so it has the highest boiling point.
CH₃Cl has a C-Cl polar covalent bond. It has dipole-dipole forces, so it has the second lowest boiling point.
CH₃OH has an O-H bond. It has hydrogen bonding, so it has the second highest boiling point.
CH₄ has nonpolar covalent C-H bonds. It has only nonpolar bonds, so the only attractive forces are London dispersion forces. It has the lowest boiling point.
Thus, the order of increasing boiling points is
CH₄ < CH₃Cl < CH₃OH < RbCl
