Answer:
90% to 97% pure tungsten in a matrix of nickel and copper or nickel and iron.
Explanation:
Heavy metal tungsten alloys are 90% to 97% pure tungsten in a matrix of nickel and copper or nickel and iron. The addition of these alloying elements improves both the ductility and machinability of these alloys over non-alloyed tungsten.
0.347 mols, working out shown on photo
Answer is: the combined ionic bond strength of CrCl₂ and intermolecular forces between water molecules.
When chromium chloride (CrCl₂) is dissolved in water, the temperature of the water increases, heat of the solution is endothermic.
Dissociation of chromium chloride in water: CrCl₂(aq) → Cr²⁺(aq) + 2Cl⁻(aq).
Energy (the lattice energy) is required to pull apart the oppositely charged ions in chromium chloride.
The heat of hydration is liberated energy when the separated ions (in this example chromium cations and chlorine anions) attract polar water molecules.
Because the lattice energy is higher than the heat of the hydration (endothermic reaction), we can conclude that bonds between ions are strong (the electrostatic attraction between oppositely charged ions).
Answer:
See explanation
Explanation:
We can describe electrons using four sets of quantum numbers;
principal quantum number (n)
orbital quantum number (l)
magnetic quantum number (ml)
spin quantum number (ms)
Since no two electrons in an atom can have the same value for all four quantum numbers according to Pauli exclusion theory, for the orbitals given one possible value for each quantum number is shown below;
For 1s-
n = 1, l= 0, ml = 0, ms= 1/2
For 2s-
n= 2, l =0, ml=0, ms=1/2
For 1s and 2s orbitals, there is only one possible value for ml which is zero.
<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>
