Question

name:
compounds with polyatomic ions
write the formula for each compound below:
a) sodium carbonate
b) strontium chlorate
c) cesium cyanide
d) zinc hydrogen sulphate
e) strontium phosphate
f) calcium hydroxide
g) ammonium sulphide
h) ammonium suphate
i) ammonium sulphite
j) copper (ii) nitrate
k) potassium dichromate
l) sodium oxalate
m) magnesium sulphite
n) lead (ii) perchlorate
o) tin (iv) phosphate
p) aluminum hydroxide
q) barium hydroxide
r) beryllium carbonate
write the name of each compound below:
a) ( \text{li}_2\text{co}_3 )
b) ( \text{mg(hco}_3\text{)}_2 )
c) ( \text{na}_2\text{so}_4 )
d) ( \text{k}_2\text{so}_3 )
e) ( \text{ba(oh)}_2 )
f) ( \text{al(cn)}_3 )
g) ( (\text{nh}_4)_3\text{po}_4 )
h) ( \text{fe(no}_3\text{)}_2 )
i) ( \text{mg(oh)}_2 )
j) ( \text{cu}_3\text{po}_4 )
k) ( \text{ag}_2\text{cro}_4 )
l) ( \text{rb}_2\text{cr}_2\text{o}_7 )
m) ( \text{nh}_4\text{f} )
n) ( \text{co(hso}_3\text{)}_2 )
o) ( \text{k}_2\text{so}_4 )
p) ( \text{pb(no}_3\text{)}_4 )
q) ( \text{nh}_4\text{no}_2 )
r) ( \text{nach}_3\text{coo} )

Answer:

Part 1: Writing Formulas for Compounds with Polyatomic Ions

a) Sodium Carbonate

• Step 1: Identify ions. Sodium ($\text{Na}^+$), carbonate ($\text{CO}_3^{2-}$).
• Step 2: Balance charges. $2 \times (+1) + 1 \times (-2) = 0$.
• Formula: $\text{Na}_2\text{CO}_3$

b) Strontium Chlorate

• Step 1: Ions: Strontium ($\text{Sr}^{2+}$), chlorate ($\text{ClO}_3^-$).
• Step 2: Balance charges. $1 \times (+2) + 2 \times (-1) = 0$.
• Formula: $\text{Sr(ClO}_3\text{)}_2$

c) Cesium Cyanide

• Step 1: Ions: Cesium ($\text{Cs}^+$), cyanide ($\text{CN}^-$).
• Step 2: Balance charges. $1 \times (+1) + 1 \times (-1) = 0$.
• Formula: $\text{CsCN}$

d) Zinc Hydrogen Sulfate

• Step 1: Ions: Zinc ($\text{Zn}^{2+}$), hydrogen sulfate ($\text{HSO}_4^-$).
• Step 2: Balance charges. $1 \times (+2) + 2 \times (-1) = 0$.
• Formula: $\text{Zn(HSO}_4\text{)}_2$ (Note: Original $\text{ZnH}_2\text{SO}_4$ is incorrect; correct is $\text{Zn(HSO}_4\text{)}_2$)

e) Strontium Phosphate

• Step 1: Ions: Strontium ($\text{Sr}^{2+}$), phosphate ($\text{PO}_4^{3-}$).
• Step 2: Balance charges. $3 \times (+2) + 2 \times (-3) = 0$.
• Formula: $\text{Sr}_3(\text{PO}_4)_2$

f) Calcium Hydroxide

• Step 1: Ions: Calcium ($\text{Ca}^{2+}$), hydroxide ($\text{OH}^-$).
• Step 2: Balance charges. $1 \times (+2) + 2 \times (-1) = 0$.
• Formula: $\text{Ca(OH)}_2$

g) Ammonium Sulfide

• Step 1: Ions: Ammonium ($\text{NH}_4^+$), sulfide ($\text{S}^{2-}$).
• Step 2: Balance charges. $2 \times (+1) + 1 \times (-2) = 0$.
• Formula: $(\text{NH}_4)_2\text{S}$

h) Ammonium Sulfate

• Step 1: Ions: Ammonium ($\text{NH}_4^+$), sulfate ($\text{SO}_4^{2-}$).
• Step 2: Balance charges. $2 \times (+1) + 1 \times (-2) = 0$.
• Formula: $(\text{NH}_4)_2\text{SO}_4$

i) Ammonium Sulfite

• Step 1: Ions: Ammonium ($\text{NH}_4^+$), sulfite ($\text{SO}_3^{2-}$).
• Step 2: Balance charges. $2 \times (+1) + 1 \times (-2) = 0$.
• Formula: $(\text{NH}_4)_2\text{SO}_3$

j) Copper (II) Nitrate

• Step 1: Ions: Copper (II) ($\text{Cu}^{2+}$), nitrate ($\text{NO}_3^-$).
• Step 2: Balance charges. $1 \times (+2) + 2 \times (-1) = 0$.
• Formula: $\text{Cu(NO}_3\text{)}_2$

k) Potassium Dichromate

• Step 1: Ions: Potassium ($\text{K}^+$), dichromate ($\text{Cr}_2\text{O}_7^{2-}$).
• Step 2: Balance charges. $2 \times (+1) + 1 \times (-2) = 0$.
• Formula: $\text{K}_2\text{Cr}_2\text{O}_7$

l) Sodium Oxalate

• Step 1: Ions: Sodium ($\text{Na}^+$), oxalate ($\text{C}_2\text{O}_4^{2-}$).
• Step 2: Balance charges. $2 \times (+1) + 1 \times (-2) = 0$.
• Formula: $\text{Na}_2\text{C}_2\text{O}_4$

m) Magnesium Sulfite

• Step 1: Ions: Magnesium ($\text{Mg}^{2+}$), sulfite ($\text{SO}_3^{2-}$).
• Step 2: Balance charges. $1 \times (+2) + 1 \times (-2) = 0$.
• Formula: $\text{MgSO}_3$

n) Lead (II) Perchlorate

• Step 1: Ions: Lead (II) ($\text{Pb}^{2+}$), perchlorate ($\text{ClO}_4^-$).
• Step 2: Balance charges. $1 \times (+2) + 2 \times (-1) = 0$.
• Formula: $\text{Pb(ClO}_4\text{)}_2$

o) Tin (IV) Phosphate

• Step 1: Ions: Tin (IV) ($\text{Sn}^{4+}$), phosphate ($\text{PO}_4^{3-}$).
• Step 2: Balance charges. $3 \times (+4) + 4 \times (-3) = 0$.
• Formula: $\text{Sn}_3(\text{PO}_4)_4$

p) Aluminum Hydroxide

• Step 1: Ions: Aluminum ($\text{Al}^{3+}$), hydroxide ($\text{OH}^-$).
• Step 2: Balance charges. $1 \times (+3) + 3 \times (-1) = 0$.
• Formula: $\text{Al(OH)}_3$

q) Barium Hydroxide

• Step 1: Ions: Barium ($\text{Ba}^{2+}$), hydroxide ($\text{OH}^-$).
• Step 2: Balance charges. $1 \times (+2) + 2 \times (-1) = 0$.
• Formula: $\text{Ba(OH)}_2$

r) Beryllium Carbonate

• Step 1: Ions: Beryllium ($\text{Be}^{2+}$), carbonate ($\text{CO}_3^{2-}$).
• Step 2: Balance charges. $1 \times (+2) + 1 \times (-2) = 0$.
• Formula: $\text{BeCO}_3$

Part 2: Naming Compounds from Formulas

a) $\text{Li}_2\text{CO}_3$

• Step 1: Cation: Lithium ($\text{Li}^+$), anion: Carbonate ($\text{CO}_3^{2-}$).
• Name: Lithium Carbonate

b) $\text{Mg(HCO}_3\text{)}_2$

• Step 1: Cation: Magnesium ($\text{Mg}^{2+}$), anion: Hydrogen Carbonate ($\text{HCO}_3^-$).
• Name: Magnesium Hydrogen Carbonate (or Magnesium Bicarbonate)

c) $\text{Na}_2\text{SO}_4$

• Step 1: Cation: Sodium ($\text{Na}^+$), anion: Sulfate ($\text{SO}_4^{2-}$).
• Name: Sodium Sulfate

d) $\text{K}_2\text{SO}_3$

• Step 1: Cation: Potassium ($\text{K}^+$), anion: Sulfite ($\text{SO}_3^{2-}$).
• Name: Potassium Sulfite

e) $\text{Ba(OH)}_2$

• Step 1: Cation: Barium ($\text{Ba}^{2+}$), anion: Hydroxide ($\text{OH}^-$).
• Name: Barium Hydroxide

f) $\text{Al(CN)}_3$

• Step 1: Cation: Aluminum ($\text{Al}^{3+}$), anion: Cyanide ($\text{CN}^-$).
• Name: Aluminum Cyanide

g) $(\text{NH}_4)_3\text{PO}_4$

• Step 1: Cation: Ammonium ($\text{NH}_4^+$), anion: Phosphate ($\text{PO}_4^{3-}$).
• Name: Ammonium Phosphate

h) $\text{Fe(NO}_3\text{)}_2$

• Step 1: Cation: Iron (II) ($\text{Fe}^{2+}$), anion: Nitrate ($\text{NO}_3^-$).
• Name: Iron (II) Nitrate (or Ferrous Nitrate)

i) $\text{Mg(OH)}_2$

• Step 1: Cation: Magnesium ($\text{Mg}^{2+}$), anion: Hydroxide ($\text{OH}^-$).
• Name: Magnesium Hydroxide

j) $\text{Cu}_3\text{PO}_4$

• Step 1: Cation: Copper (I) ($\text{Cu}^+$), anion: Phosphate ($\text{PO}_4^{3-}$).
• Name: Copper (I) Phosphate (or Cuprous Phosphate)

k) $\text{Ag}_2\text{CrO}_4$

• Step 1: Cation: Silver ($\text{Ag}^+$), anion: Chromate ($\text{CrO}_4^{2-}$).
• Name: Silver Chromate

l) $\text{Rb}_2\text{Cr}_2\text{O}_7$

• Step 1: Cation: Rubidium ($\text{Rb}^+$), anion: Dichromate ($\text{Cr}_2\text{O}_7^{2-}$).
• Name: Rubidium Dichromate

m) $\text{NH}_4\text{F}$

• Step 1: Cation: Ammonium ($\text{NH}_4^+$), anion: Fluoride ($\text{F}^-$).
• Name: Ammonium Fluoride

n) $\text{Co(HSO}_3\text{)}_2$

• Step 1: Cation: Cobalt (II) ($\text{Co}^{2+}$), anion: Hydrogen Sulfite ($\text{HSO}_3^-$).
• Name: Cobalt (II) Hydrogen Sulfite (or Cobalt (II) Bisulfite)

o) $\text{K}_2\text{SO}_4$

• Step 1: Cation: Potassium ($\text{K}^+$), anion: Sulfate ($\text{SO}_4^{2-}$).
• Name: Potassium Sulfate

p) $\text{Pb(NO}_3\text{)}_4$

• Step 1: Cation: Lead (IV) ($\text{Pb}^{4+}$), anion: Nitrate ($\text{NO}_3^-$).
• Step 2: Balance: $1 \times (+4) + 4 \times (-1) = 0$.
• Name: Lead (IV) Nitrate (or Plumbic Nitrate)

q) $\text{NH}_4\text{NO}_2$

• Step 1: Cation: Ammonium ($\text{NH}_4^+$), anion: Nitrite ($\text{NO}_2^-$).
• Name: Ammonium Nitrite

r) $\text{NaCH}_3\text{COO}$

• Step 1: Cation: Sodium ($\text{Na}^+$), anion: Acetate ($\text{CH}_3\text{COO}^-$).
• Name: Sodium Acetate

Final Answers (Selected Examples)

Formula Writing (e.g., a, j, k):

a) $\boldsymbol{\text{Na}_2\text{CO}_3}$; j) $\boldsymbol{\text{Cu(NO}_3\text{)}_2}$; k) $\boldsymbol{\text{K}_2\text{Cr}_2\text{O}_7}$

Naming (e.g., a, j, k):

a) Lithium Carbonate; j) Copper (I) Phosphate; k) Silver Chromate

(Note: For full answers, apply the same logic to all sub-questions.)