<< Chapter < Page Chapter >> Page >

A final check of atom and charge balance confirms the equation is balanced.

Reactants Products
Fe 6 6
Cr 2 2
O 7 7
H 14 14
charge 24+ 24+

Check your learning

In acidic solution, hydrogen peroxide reacts with Fe 2+ to produce Fe 3+ and H 2 O. Write a balanced equation for this reaction.

Answer:

H 2 O 2 ( a q ) + 2 H + ( a q ) + 2 Fe 2+ 2 H 2 O ( l ) + 2 Fe 3+

Key concepts and summary

Chemical reactions are classified according to similar patterns of behavior. A large number of important reactions are included in three categories: precipitation, acid-base, and oxidation-reduction (redox). Precipitation reactions involve the formation of one or more insoluble products. Acid-base reactions involve the transfer of hydrogen ions between reactants. Redox reactions involve a change in oxidation number for one or more reactant elements. Writing balanced equations for some redox reactions that occur in aqueous solutions is simplified by using a systematic approach called the half-reaction method.

Chemistry end of chapter exercises

Use the following equations to answer the next five questions:

i. H 2 O ( s ) H 2 O ( l )

ii. Na + ( a q ) + Cl ( aq ) + Ag + ( a q ) + NO 3 ( a q ) AgCl ( s ) + Na + ( a q ) + NO 3 ( a q )

iii. CH 3 OH ( g ) + O 2 ( g ) CO 2 ( g ) + H 2 O ( g )

iv. 2 H 2 O ( l ) 2 H 2 ( g ) + O 2 ( g )

v. H + ( a q ) + OH ( a q ) H 2 O ( l )

(a) Which equation describes a physical change?

(b) Which equation identifies the reactants and products of a combustion reaction?

(c) Which equation is not balanced?

(d) Which is a net ionic equation?

Got questions? Get instant answers now!

Indicate what type, or types, of reaction each of the following represents:

(a) Ca ( s ) + Br 2 ( l ) CaBr 2 ( s )

(b) Ca (OH) 2 ( a q ) + 2 HBr ( a q ) CaBr 2 ( a q ) + 2 H 2 O ( l )

(c) C 6 H 12 ( l ) + 9 O 2 ( g ) 6 CO 2 ( g ) + 6 H 2 O ( g )

(a) oxidation-reduction (addition); (b) acid-base (neutralization); (c) oxidation-reduction (combustion)

Got questions? Get instant answers now!

Indicate what type, or types, of reaction each of the following represents:

(a) H 2 O ( g ) + C ( s ) CO ( g ) + H 2 ( g )

(b) 2KClO 3 ( s ) 2 KCl ( s ) + 3 O 2 ( g )

(c) Al (OH) 3 ( a q ) + 3 HCl ( a q ) AlCl 3 ( a q ) + 3 H 2 O ( l )

(d) Pb ( NO 3 ) 2 ( a q ) + H 2 SO 4 ( a q ) PbSO 4 ( s ) + 2 HNO 3 ( a q )

Got questions? Get instant answers now!

Silver can be separated from gold because silver dissolves in nitric acid while gold does not. Is the dissolution of silver in nitric acid an acid-base reaction or an oxidation-reduction reaction? Explain your answer.

It is an oxidation-reduction reaction because the oxidation state of the silver changes during the reaction.

Got questions? Get instant answers now!

Determine the oxidation states of the elements in the following compounds:

(a) NaI

(b) GdCl 3

(c) LiNO 3

(d) H 2 Se

(e) Mg 2 Si

(f) RbO 2 , rubidium superoxide

(g) HF

Got questions? Get instant answers now!

Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides.

(a) H 3 PO 4

(b) Al(OH) 3

(c) SeO 2

(d) KNO 2

(e) In 2 S 3

(f) P 4 O 6

(a) H +1, P +5, O −2; (b) Al +3, H +1, O −2; (c) Se +4, O −2; (d) K +1, N +3, O −2; (e) In +3, S −2; (f) P +3, O −2

Got questions? Get instant answers now!

Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides.

(a) H 2 SO 4

(b) Ca(OH) 2

(c) BrOH

(d) ClNO 2

(e) TiCl 4

(f) NaH

Got questions? Get instant answers now!

Classify the following as acid-base reactions or oxidation-reduction reactions:

(a) Na 2 S ( a q ) + 2 HCl ( a q ) 2 NaCl ( a q ) + H 2 S ( g )

(b) 2 Na ( s ) + 2 HCl ( a q ) 2 NaCl ( a q ) + H 2 ( g )

(c) Mg ( s ) + Cl 2 ( g ) MgCl 2 ( s )

(d) MgO ( s ) + 2 HCl ( a q ) MgCl 2 ( a q ) + H 2 O ( l )

(e) K 3 P ( s ) + 2 O 2 ( g ) K 3 PO 4 ( s )

(f) 3 KOH ( a q ) + H 3 PO 4 ( a q ) K 3 PO 4 ( a q ) + 3 H 2 O ( l )

(a) acid-base; (b) oxidation-reduction: Na is oxidized, H + is reduced; (c) oxidation-reduction: Mg is oxidized, Cl 2 is reduced; (d) acid-base; (e) oxidation-reduction: P 3− is oxidized, O 2 is reduced; (f) acid-base

Got questions? Get instant answers now!

Questions & Answers

what are components of cells
ofosola Reply
twugzfisfjxxkvdsifgfuy7 it
Sami
58214993
Sami
what is a salt
John
the difference between male and female reproduction
John
what is computed
IBRAHIM Reply
what is biology
IBRAHIM
what is the full meaning of biology
IBRAHIM
what is biology
Jeneba
what is cell
Kuot
425844168
Sami
what is cytoplasm
Emmanuel Reply
structure of an animal cell
Arrey Reply
what happens when the eustachian tube is blocked
Puseletso Reply
what's atoms
Achol Reply
discuss how the following factors such as predation risk, competition and habitat structure influence animal's foraging behavior in essay form
Burnet Reply
cell?
Kuot
location of cervical vertebra
KENNEDY Reply
What are acid
Sheriff Reply
define biology infour way
Happiness Reply
What are types of cell
Nansoh Reply
how can I get this book
Gatyin Reply
what is lump
Chineye Reply
what is cell
Maluak Reply
what is biology
Maluak
what is vertibrate
Jeneba
what's cornea?
Majak Reply
what are cell
Achol
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Chemistry' conversation and receive update notifications?

Ask