Answer:
the plant population over time has decreased. this could make all other organisms above the plant population numbers decrease as well.
Explanation:
Enzymes are needed for metabolic pathways in the body, respiration, digestion and other important life processes. When enzymes function properly, homeostasis is maintained. However, if an enzyme is lacking or has an incorrect shape due to genetic mutation, this can lead to disease within an organism.
Answer:
the speed of the earth's rotation, the tilt of the earth's axis and the directness of the sun
Answer:
(a) oxygen
(b) 154g (to 3sf)
(c) 79.9% (to 3sf)
Explanation:
mass (g) = moles × Mr/Ar
note: eqn means chemical equation
(a)
moles of P = 84.1 ÷ 30.973 = 2.7152 moles
moles of O2 = 85÷2(16) = 2.65625 moles
Assuming all the moles of P is used up,
moles of O2 / moles of phosphorus = 5/4 (according to balanced chemical eqn)
moles of O2 required = 5/4 × 2.7152moles = 3.394 moles (more than supplied which is 2.65625moles)
therefore there is insufficient moles of O2 and the limiting reactant is oxygen.
(b)
moles of P2O5 produced
= 2/5 (according to eqn) × 2.7152
= 1.08608moles
mass of P2O5 produced
= 1.08608 × [ 2(30.973) + 5(16) ]
= 154.164g
= approx. 154g to 3 sig. fig.
(c)
% yield = actual/theoretical yield × 100%
= 123/154 × 100%
= 79.870%
= approx. 79.9% (to 3sf)
<span>Use the van't Hoff equation:
ln
(
K2
K1
)
=
Δ
HÂş
R
(
1
T1
â’
1
T2
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ln
(
K2
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)
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-14,200 J
8.314
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1
298
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1
333
)
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(
K2
7.6*10^-3
)
=
â’
1708
(
0.00035
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ln
(
K2
0.0076
)
=
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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
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0.598
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4.2
â‹…
10
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3
K2
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4.2
â‹…
10
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3</span>
