We first calculate the heat released:
Specific heat = 3.21 kJ/kgK
Heat released = heat absorbed by calorimeter
Heat absorbed = mcΔT
= 1.9 x 3.21 x 4.542
= 27.7 kJ
Now, we calculate the moles of hexane present:
Moles = mass / Mr
moles = 0.58 / (12 x 6 + 14)
= 0.0067
Heat of combustion = 27.7 / 0.0067 kJ/mol
ΔH(combustion) = 4,134.3 kJ / mol
Answer:
- <em><u>2I ⁻ → I₂ + 2e⁻</u></em> describes the <em><u>oxidation.</u></em>
- <u><em>Cl₂ + 2e⁻ → 2Cl ⁻</em></u> describes the <u><em>reduction</em></u>.
Explanation:
<em>Oxidation-reduction reaction</em> is the simulaneous oxidation and reduction of the substances and is represented by two half-reactions.
The <em>oxidation</em> half-reaction is the loss of electrons, with the consequent increase in the oxidation state by the oxidized substance.
In this case, the process that shows the loss of electrons is:
That reaction shows:
- Two I⁻ ions lose two electrons (one each) to be oxidized to I₂.
- The change in the oxidation number is from -1 to 0.
- Hence this half-reaction is the oxidation reaction.
On the other hand, the <em>reduction</em> half-reaction is the gain of electrons, with the consequent reduction of the oxidation state by the reduced substance.
In this case, the process that shows the gain of electrons is:
That reaction shows:
- Two Cl atoms gain two electrons (one each) to be reduced to Cl⁻.
- The change in the oxidation number is from 0 to - 1.
- Hence, this half-reaction is the reduction reaction.
<u>Summary:</u>
- <em>2I ⁻ → I₂</em> + 2e⁻ describes the oxidation.
- <em>Cl₂ + 2e⁻ → 2Cl ⁻</em> describes the reduction.
The density of the rock in g/mL : 14 g/ml
Complete question :
A rock with a mass of 70 grams is dropped into a graduated cylinder with 30 mL of water in it. The water level rose to 35 mL calculate the density of the rock in g/mL
<h3>Further explanation</h3>
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:
ρ = density
m = mass
v = volume
mass of rock = 70 g
Volume of the rock : 35 - 30 = 5 ml
So the density :
