61. write formulas for the compounds:

(a) aluminum sulfate;

(b) ammonium dichromate;

(c) silicon tetrafluoride;

(d) iron(iii) oxide;

(e) tricarbon disulfide;

(f) cobalt(ii) nitrate;

(g) strontium nitrite;

(h) hydrobromic acid;

(i) iodic acid;

(j) phosphorus dichloride trifluoride.

See explanation

Explanation:

(a) aluminum sulfate:

⇒ Al^3+ has oxidation number +3

⇒ SO4^2- has oxidation number -2

→ Al2(SO4)3

(b) ammonium dichromate:

 ⇒ NH4^+ has oxidation number +1

 ⇒ Cr2O7^2- has oxidation number -2

→ (NH4)2Cr2O7

(c) silicon tetrafluoride:

 ⇒ Si^4+ has oxidation number of +4

 ⇒ F- has an oxidation number of -1

→ SiF

(d) iron(III) oxide:

 ⇒ Fe^3+ has an oxidation number of +3

 ⇒ O has an oxidation number of -2

→ Fe2O3

(e) tricarbon disulfide:

→ C3S2

(f) cobalt(II) nitrate:

⇒ C has an oxidation number of +2

⇒ NO3- has an oxidation number of -1

→C(NO3)2

(g) strontium nitrite:

 ⇒ NO2- has an oxidation number of -1

 ⇒ Sr has an oxidation number of +2

→Sr(NO2)2   (N2O4Sr)

(h) hydrobromic acid:

 ⇒ H+ has an oxidation number of +1

 ⇒ Br- has an oxidation number of -1

→HBr

(i) iodic acid:

 ⇒ H+ has an oxidation number of +1

 ⇒ IO3- has an oxidation number of -1

→HIO3

(j) phosphorus dichloride trifluoride:

⇒ P has an oxidation number of +5

⇒ F has an oxidation number of -1

⇒ Cl has an oxidation number of -1

→PF3Cl2

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