Below are the choices:
a. −166 kJ/mol
<span>b. 166 kJ/mol </span>
<span>c. 1.64 kJ/mol </span>
<span>d. 1.66 × 10^5 kJ/mol
</span>
To calculate the activation energy of a reaction, we use the Arrhenius equation. You may want to look it up to see how and why it works. In the problem you posted, there are two temperatures and two rate constants. After some rearranging and substitution of the Arrhenius equation, we have Ea = R T1 T2/(T1-T2) ln(k1/k2) = 8.314 J/mol K (600 K)(650 K)/(600 K-650 K) ln(2.7×10^-4 M^−1sec^−1/3.5×10^−3 M−^1sec^−1) = 166145 J/mol = 166 kJ/mol => choice b
Answer:
Fe.
Explanation:
- The element which is oxidized is the element that losses electrons and its oxidation state be more positive.
- The element which is reduced is the element that gain electrons and its oxidation state be more negative.
<em> Fe goes from + 2 to +3, so, it is the element that is oxidized.</em>
<em></em>
Na: +1 (sodium)
S: -2 (sulfur)
=> Na2S
Answer:
S₁₂
Explanation:
The freezing point depression (ΔTf) is a colligative property that can be calculated using the following expression.
ΔTf = Kf × m
where,
Kf: freezing point depression
m: molality
ΔTf = Kf × m
m = ΔTf / Kf
m = 0.156 °C / (29.8 °C/m)
m = 5.23 × 10⁻³ m
The molality is:
m = moles of solute / kilograms of solvent
moles of solute = m × kilograms of solvent
moles of solute = 5.23 × 10⁻³ mol/kg × 0.5000 kg
moles of solute = 2.62 × 10⁻³ mol
1.00 g corresponds to 2.62 × 10⁻³ moles. The molar mass of Sₙ is:
1.00 g/2.62 × 10⁻³ mol = 382 g/mol
We can calculate n.
n = molar mass of Sₙ / molar mass of S
n = (382 g/mol) / (32.0 g/mol)
n = 11.9 ≈ 12
The molar formula is S₁₂.
Answer:
A metallic bond is the sharing of many detached electrons between many positive ions, where the electrons act as a "glue" giving the substance a definite structure. It is unlike covalent or ionic bonding. Metals have low ionization energy. Therefore, the valence electrons can be delocalized throughout the metals.
