I think it might be D or B
And my other two might be A or C
1. NaF, Na₂S, Na₃P, Na₂O
2. MgF₂, MgS, Mg₃P₂, MgO
3. AlF₃, Al₂S₃, AlP, Al₂O₃
<h3>Further explanation</h3>
Given
Ionic charge
Required
The formula of binary ionic compounds
Solution
Ionic compounds consisting of cations (ions +) and anions (ions -)
Ionic compounds usually consist of metal cations and non-metal anions
Metal: cation, positively charged.
Nonmetal: negatively charged
The anion cation's charge is crossed
The ionic compounds :
1. NaF, Na₂S, Na₃P, Na₂O
2. MgF₂, MgS, Mg₃P₂, MgO
3. AlF₃, Al₂S₃, AlP, Al₂O₃
The answer for four is frequency.
Answer is: formula of the complex is [Cr(NH₃)₂(SCN)₄<span>]</span>⁻<span>.
This complex has negative charge (-1) because chromium (central atom or metal) has oxidation number +3, first ligand ammonia has neutral charge and second ligand thiocyanate has negative oxidation number -1:
+3 + 2</span>·0 + 4·(-1) = -1.
The formula for pH given the pKa and the concentrations
are:
pH = pKa + log [a–]/[ha]
<span>
Therefore calculating:</span>
3.75 = 3.75 + log [a–]/[ha]
log [a–]/[ha] = 0
[a–]/[ha] = 10^0
<span>[a–]/[ha] = 1</span>