Answer:
a) [A⁻]/[HA] = 0.227
b) [A⁻]/[HA] = 0.991
c) [A⁻]/[HA] = 2.667
Explanation:
In the Henderson-Hasselbalch equation, HA stands from an acid an A⁻ stands from its conjugate base, as follows:
pH = pka + Log [A⁻]/[HA]
pH = 4.874 + Log[CH₃CH₂CO₂⁻]/[CH₃CH₂CO₂H]
4.23 = 4.874 + Log [A⁻]/[HA]
-0.644 = Log [A⁻]/[HA]
= [A⁻]/[HA]
0.227 = [A⁻]/[HA]
4.87 = 4.874 + Log [A⁻]/[HA]
-0.004 = Log [A⁻]/[HA]
= [A⁻]/[HA]
0.991 = [A⁻]/[HA]
5.30 = 4.874 + Log [A⁻]/[HA]
0.426 = Log [A⁻]/[HA]
= [A⁻]/[HA]
2.667 = [A⁻]/[HA]
Answer:
The number of neutrons present in one atom of isotope of Silicon of mass 28 amu is<u> 14 neutrons</u>
Explanation:
Symbol of Si isotope
<u>Number of Neutron = Mass number - Atomic Number</u>
Mass number = Total number of protons and neutrons present in the nucleus of the atom.For Si = 28 amu
Atomic Number = Total number of Protons present in the nucleus.
Si = 14
Number of neutron = 24 - 14
= 14
It has oribited the milky way more then 20 times
D. Two electrons in its first energy level; eight electrons in its second energy level; six valence electrons in its outermost energy level.
Please correct me if I'm wrong!! :)
Answer:
1.8 × 10² cal
Explanation:
When 0.32 g of a walnut is burned, the heat released is absorbed by water and used to raise its temperature. We can calculate this heat (Q) using the following expression.
Q = c × m × ΔT
where,
c: specific heat capacity of water
m: mass of water
ΔT: change in the temperature
Considering the density of water is 1 g/mL, 58.1 mL = 58.1 g.
Q = c × m × ΔT
Q = (1 cal/g.°C) × 58.1 g × 3.1°C
Q = 1.8 × 10² cal
