Answer:
it's a diatomic molecule–which is why it is O₂.
Explanation:
Diatomic molecules are molecules composed of only two atoms, of the same or different chemical elements. Only a handful of elements on the periodic table are diatomic such as nitrogen, hydrogen, fluorine, chlorine, bromine, and iodine.
<span>Use the van't Hoff equation:
ln
(
K2
K1
)
=
Δ
HÂş
R
(
1
T1
â’
1
T2
)
ln
(
K2
7.6*10^-3
)
=
-14,200 J
8.314
(
1
298
â’
1
333
)
ln
(
K2
7.6*10^-3
)
=
â’
1708
(
0.00035
)
ln
(
K2
0.0076
)
=
â’
0.598
Apply log rule
a
=
log
b
b
a
-0.598 =
ln
(
e
â’
0.598
)
=
ln
(
1
e
0.598
)
Multiply both sides with e^0.598
K
2
e
0.598
= 0.0076
K
e
0.598
e
0.598
=
0.0076
e
0.598
K
2
=
0.0076
e
0.598
=
4.2
â‹…
10
â’
3
K2
=
4.2
â‹…
10
â’
3</span>
Above is a potential energy curve of a reaction. It depicts conversion of reactant to product via transition state.
When a catalyst is added to the reaction system, energy barrier of reaction decreases.
It must be noted that energy barrier reaction is defined as energy difference between reactant and transition state.
In present case, energy of reactant is 200 kj, while that of transition state (in absence of catalyst) is 650 kj
Thus, energy barrier of reaction is 650 - 200 = 450 kj
<span>Hence, system must absorb 450 kj of energy for the reaction to start, if no catalyst was used</span>
kg and all the given units are units used to measure mass.
kg is the standard unit to measure mass
lets find the value of 0.00684 kg in all the given units
a. dkg
1 kg is equivalent to 100 decagram (dkg)
therefore 0.00684 kg is = 100 dkg/kg x 0.00684 kg = 0.684 dkg
this is not the given value therefore this choice is incorrect
b. 1 kg is equivalent to 1000 g
therefore 0.00684 kg = 1000 g/kg x 0.00684 kg = 6.84 g
this is the given value so this is correct
c. 1 kg is equivalent to 100 000 centigrams (cg)
therefore 0.00684 kg = 100 000 cg/kg x 0.00684 kg = 684 cg
this is the given value so this is also correct
d) 1 kg is equivalent to 1 000 000 mg
therefore 0.00684 kg = 1 000 000 mg/kg x 0.00684 kg = 6 840 mg
this too is correct
the incorrect answer is A. 0.0684 dkg
