<span>The effective nuclear charge of an atom = total electrons - inner electrons
For O, ENC = 8 - 2 = 6
For Li, ENC = 3 - 2 = 1
For C, ENC = 6 - 2 = 4
The electrons in O experience the greatest effective nuclear charge and that is why O is smaller than C (which is smaller than Li).</span>
Answer:
MgCl2 - 6H2O
203.3 mol
MgCl2 + 2Na = 2NaCl + Mg
22.6g
Explanation:
1. Write the formula of hydrate and find molar mass.
2. Write a balanced single replacement (don't include H2O)
3. Do the given/wanted calculation (include H2O in molar mass of given)
Answer:
ΔS = - 0.125 Kj/K decreased entropy
Explanation:
From ΔH = TΔS => ΔS = ΔH/T
= 100Kj/(600K - 1400K) = - 188Kj/800K = - 0.125 Kj/K
Entropy in the cooler flask would have 'decreased' (i.e.; more ordered state) at 600K.
Stellar nebula, star, red giant, planetary nebula and then a white dwarf.
Answer:
A. 1.62
B. 0.513
C. 0.162.
Explanation:
pH = pKa + log [ HPO42-] / [H2PO4-]
Assuming, pKa is 7.21
Ka = 6.2 x 10^-8
pKa = 7.21
A.
7.0 = 7.21 + log [HPO42-] / [HPO4-]
- 0.21 = log [ HPO42-] / [H2PO4-]
[ HPO42-] / [ H2PO4-] = 10^-0.21
= 0.617
[H2PO4-] / [HPO42-] = 1 / 0.617
= 1.62
B.
7.5 = 7.21 + log [HPO42-] / [H2PO4-]
0.29 = log [HPO42-] / [H2PO4-]
[HPO42-] / [H2PO4-] = 10^0.29
= 1.95
[H2PO4-] / [HPO42-] = 1/1.95
= 0.513
8.0 = 7.21 + log [HPO42-] / [ H2PO4-]
0.79 = log [HPO42-] / [H2PO4-]
[HPO42-] / [H2PO4-] = 10^0.79
= 6.17
[H2PO4-] / [HPO42-] = 1/6.17
= 0.162
