Answer:
A. True
B. False
C. False
D. True
E. False
Explanation:
A. The proximal histidine covalently binds iron.
This statement is true because the proximal histidine is covalently bonded to the fifth coordination position of iron in myoglobin
B. The distal histidine covalently binds oxygen.
This statement is false because the distal histidine interacts with the oxygen covalently bonded to the sixty coordination position of iron by means of a hydrogen bond not a covalent bond.
C. The distal histidine binds iron
This statement is false because the distal histidine is not bonded to iron but to oxygen but stabilizes the oxygen bonded to iron
D. Free heme binds CO with the Fe, C and O atoms in a linear array.
This statement is true because free heme has more affinity for CO than O2 as it has the least steric hindrance when the Fe, C, and O atoms lie in a straight line. On the other hand, when O2 binds to free heme, the axis of the oxygen molecule is positioned at an angle to the Fe-O bond thereby producing significant steric hindrance.
E. The iron in heme binds the oxygen atom of CO.
This statement is false because the iron in heme binds to the carbon atom, C, of CO rather than to oxygen atom.
Answer:
Q = 31798.4J = 31.79kJ
Explanation:
Heat energy (Q) = ?
Mass (m) = 152g
T1 = 24°C
T2 = 74°C
Specific heat capacity of water (c) = 4.184J/g°C
Q = Mc∇T
Q = 152 * 4.184 * (74 - 24)
Q = 635.968 * 50
Q = 31798.4J
Q = 31.79kJ
Heat required is 31.79kJ
<span>Answer: option B. 3.07 g
Explanation:
1) given reaction:
S(s) + O₂ (g) → SO(g)
2) Balanced chemical equation:
</span><span>2S(s) + O₂ (g) → 2SO(g)
3) Theoretical mole ratios:
2 mol S : 1 mol O₂ : 2 mol SO
3) number of moles of 4.5 liter SO₂ at</span><span> 300°C and 101 kPa
use the ideal gas equation:
pV = nRT
with V = 4.5 liter
p = 101 kPa
T = 300 + 273.15 K = 573.15 K
R = 8.314 liter×kPa / (mol×K)
=> n = pV / (RT) =
n = [101 kPa × 4.5 liter] / [8.314 (liter×kPa) / (mol×K) × 573.15 K ]
n = 0.0954 mol SO
4) proportion with the theoretical ratio S / SO
2 mol S x
-------------- = ----------------------
2 mol SO 0.0954 mol SO
=> x = 0.0954 mol S.
5) Convert mol of S to grams by using atomic mass of S = 32.065 g/mol
mass = number of moles × atomic mass
mass = 0.0954 mol × 32.065 g/mol = 3.059 g of S
6) Therefore the answer is the option B. 3.07 g
</span>
Answer:
Sodium hydroxide is <u>very corrosive</u>. It can cause irritation to the eyes, skin, and mucous membrane; an allergic reaction; eye and skin burns; and temporary loss of hair. Workers may be harmed from exposure to sodium hydroxide.
Explanation:
<u>How to reduce:</u>
Inhalation: Move victim to fresh air.
Skin Contact: Avoid direct contact
Eye Contact: Avoid direct contact
Ingestion: Have victim rinse mouth with water.
).
is present at the intermediate position in electrochemical series with a standard reduction potential of 0 V (
).
whereas
is reduced to
and gaseous