<< Chapter < Page Chapter >> Page >

Chemistry end of chapter exercises

Under what circumstances, if any, does a sample of solid AgCl completely dissolve in pure water?

when the amount of solid is so small that a saturated solution is not produced

Got questions? Get instant answers now!

Explain why the addition of NH 3 or HNO 3 to a saturated solution of Ag 2 CO 3 in contact with solid Ag 2 CO 3 increases the solubility of the solid.

Got questions? Get instant answers now!

Calculate the cadmium ion concentration, [Cd 2+ ], in a solution prepared by mixing 0.100 L of 0.0100 M Cd(NO 3 ) 2 with 1.150 L of 0.100 NH 3 ( aq ).

8 × 10 –5 M

Got questions? Get instant answers now!

Explain why addition of NH 3 or HNO 3 to a saturated solution of Cu(OH) 2 in contact with solid Cu(OH) 2 increases the solubility of the solid.

Got questions? Get instant answers now!

Sometimes equilibria for complex ions are described in terms of dissociation constants, K d . For the complex ion AlF 6 3− the dissociation reaction is:

AlF 6 3− Al 3+ + 6 F and K d = [ Al 3+ ] [ F ] 6 [ AlF 6 3− ] = 2 × 10 24

Calculate the value of the formation constant, K f , for AlF 6 3− .

5 × 10 23

Got questions? Get instant answers now!

Using the value of the formation constant for the complex ion Co ( NH 3 ) 6 2+ , calculate the dissociation constant.

Got questions? Get instant answers now!

Using the dissociation constant, K d = 7.8 × 10 –18 , calculate the equilibrium concentrations of Cd 2+ and CN in a 0.250- M solution of Cd ( CN ) 4 2− .


This table has two main columns and three rows. The first row for the first column does not have a heading and then has the following in the first column: Initial concentration ( M ) and Equilibrium ( M ). The second column has the header, “[ C d ( C N ) subscript 4 to the second power superscript negative sign ] [ C N superscript negative sign ] [ C d to the second power superscript positive sign ].” Under the second column is a subgroup of two rows and three columns. The first column contains the following: 0.250 and 0.250 minus x. The second column contains the following: 0 and 4 x. The third column contains the following: 0 and x.
[Cd 2+ ] = 9.5 × 10 –5 M ; [CN ] = 3.8 × 10 –4 M

Got questions? Get instant answers now!

Using the dissociation constant, K d = 3.4 × 10 –15 , calculate the equilibrium concentrations of Zn 2+ and OH in a 0.0465- M solution of Zn ( OH ) 4 2− .

Got questions? Get instant answers now!

Using the dissociation constant, K d = 2.2 × 10 –34 , calculate the equilibrium concentrations of Co 3+ and NH 3 in a 0.500- M solution of Co ( NH 3 ) 6 3+ .

[Co 3+ ] = 3.0 × 10 –6 M ; [NH 3 ] = 1.8 × 10 –5 M

Got questions? Get instant answers now!

Using the dissociation constant, K d = 1 × 10 –44 , calculate the equilibrium concentrations of Fe 3+ and CN in a 0.333 M solution of Fe ( CN ) 6 3− .

Got questions? Get instant answers now!

Calculate the mass of potassium cyanide ion that must be added to 100 mL of solution to dissolve 2.0 × 10 –2 mol of silver cyanide, AgCN.

1.3 g

Got questions? Get instant answers now!

Calculate the minimum concentration of ammonia needed in 1.0 L of solution to dissolve 3.0 × 10 –3 mol of silver bromide.

Got questions? Get instant answers now!

A roll of 35-mm black and white photographic film contains about 0.27 g of unexposed AgBr before developing. What mass of Na 2 S 2 O 3 ·5H 2 O (sodium thiosulfate pentahydrate or hypo) in 1.0 L of developer is required to dissolve the AgBr as Ag ( S 2 O 3 ) 2 3− ( K f = 4.7 × 10 13 )?

0.79 g

Got questions? Get instant answers now!

We have seen an introductory definition of an acid: An acid is a compound that reacts with water and increases the amount of hydronium ion present. In the chapter on acids and bases, we saw two more definitions of acids: a compound that donates a proton (a hydrogen ion, H + ) to another compound is called a Brønsted-Lowry acid, and a Lewis acid is any species that can accept a pair of electrons. Explain why the introductory definition is a macroscopic definition, while the Brønsted-Lowry definition and the Lewis definition are microscopic definitions.

Got questions? Get instant answers now!

Write the Lewis structures of the reactants and product of each of the following equations, and identify the Lewis acid and the Lewis base in each:

(a) CO 2 + OH HCO 3

(b) B ( OH ) 3 + OH B ( OH ) 4

(c) I + I 2 I 3

(d) AlCl 3 + Cl AlCl 4 (use Al-Cl single bonds)

(e) O 2− + SO 3 SO 4 2−

(a)
This figure shows a chemical reaction modeled with structural formulas. On the left side is a structure with a central C atom. O atoms, each with two unshared electron pairs, are double bonded to the left and right sides of the C atom. Following a plus sign is another structure in brackets which has an O atom with three unshared electron dot pairs single bonded to an H atom on the right. Outside the brackets is superscript negative sign. Following a right pointing arrow is a structure in brackets that has a central C atom to which 3 O atoms are bonded. Above and slightly to the right, one of the O atoms is connected with a double bond. This O atom has two unshared electron pairs. The second O atom is single bonded below and slightly to the right. This O atom has three unshared electron pairs. The third O atom is bonded to the left of the C atom. This O atom has two unshared electron pairs and an H atom single bonded to its left. Outside the brackets to the right is a superscript negative symbol. ;
(b)
This figure shows a chemical reaction modeled with structural formulas. On the left side is a structure that has a central B atom to which 3 O atoms are bonded. The O atoms above and below slightly right of the B atom each have an H atom single bonded to the right. The third O atom is single bonded to the left side of the B atom. This O atom has an H atom single bonded to its left side. All O atoms in this structure have two unshared electron pairs. Following a plus sign is another structure which has an O atom single bonded to an H atom on its right. The O atom has three unshared electron pairs. The structure appears in brackets with a superscript negative sign. Following a right pointing arrow is a structure in brackets has a central B atom to which 4 O atoms are bonded. The O atoms above, below, and right of the B atom each hav an H atom single bonded to the right. The third O atom is single bonded to the left side of the B atom. This O atom has an H atom single bonded to its left side. All O atoms in this structure have two unshared electron pairs. Outside the brackets to the right is a superscript negative symbol. ;
(c)
This figure illustrates a chemical reaction using structural formulas. On the left, two I atoms, each with 3 unshared electron pairs, are joined with a single bond. Following a plus sign is another structure which has an I atom with four pairs of electron dots and a superscript negative sign. Following a right pointing arrow is a structure in brackets that has three I atoms connected in a line with single bonds. The two end I atoms have three unshared electron dot pairs and the I atom at the center has two unshared electron pairs. Outside the brackets is a superscript negative sign. ;
(d)
This figure illustrates a chemical reaction using structural formulas. On the left, an A l atom is positioned at the center of a structure and three Cl atoms are single bonded above, leftt, and below. Each C l atom has three pairs of electron dots. Following a plus sign is another structure which has an F atom is surrounded by four electron dot pairs and a superscript negative symbol. Following a right pointing arrow is a structure in brackets that has a central A l atom to which 4 C l atoms are connected with single bonds above, below, to the left, and to the right. Each C l atom in this structure has three pairs of electron dots. Outside the brackets is a superscript negative symbol. ;
(e)
This figure illustrates a chemical reaction using structural formulas. On the left is a structure which has an S atom at the center. O atoms are single bonded above and below. These O atoms have three electron dot pairs each. To the right of the S atom is a double bonded O atom which has two pairs of electron dots. Following a plus sign is an O atom which is surrounded by four electron dot pairs and has a superscript 2 negative. Following a right pointing arrow is a structure in brackets that has a central S atom to which 4 O atoms are connected with single bonds above, below, to the left, and to the right. Each of the O atoms has three pairs of electron dots. Outside the brackets is a superscript 2 negative.

Got questions? Get instant answers now!

Write the Lewis structures of the reactants and product of each of the following equations, and identify the Lewis acid and the Lewis base in each:

(a) CS 2 + SH HCS 3

(b) BF 3 + F BF 4

(c) I + SnI 2 SnI 3

(d) Al ( OH ) 3 + OH Al ( OH ) 4

(e) F + SO 3 SFO 3

Got questions? Get instant answers now!

Using Lewis structures, write balanced equations for the following reactions:

(a) HCl ( g ) + PH 3 ( g )

(b) H 3 O + + CH 3

(c) CaO + SO 3

(d) NH 4 + + C 2 H 5 O

(a)
This figure represents a chemical reaction in two rows. The top row shows the reaction using chemical formulas. The second row uses structural formulas to represent the reaction. The first row contains the equation H C l ( g ) plus P H subscript 3 ( g ) right pointing arrow left bracket P H subscript 4 right bracket superscript plus plus left bracket C l with 4 pairs of electron dots right bracket superscript negative sign. The second row begins on the left with H left bracket C l with four unshared electron pairs right bracket plus a structure in brackets with a central P atom with H atoms single bonded at the left, above, and to the right. A single unshared electron pair is on the central P atom. Outside the brackets to the right is a superscript plus sign. Following a right pointing arrow is a structure in brackets with a central P atom with H atoms single bonded at the left, above, below, and to the right. Outside the brackets is a superscript plus sign. This structure is followed by a plus and a C l atom in brackets with four unshared electron pairs and a superscript negative sign. ;
(b) H 3 O + + CH 3 CH 4 + H 2 O
This figure represents a chemical reaction using structural formulas. A structure is shown in brackets on the left which is composed of a central O atom with one unshared electron pair and three single bonded H atoms to the left, right, and above the atom. Outside the brackets to the right is a superscript plus sign. Following a plus sign, is another structure in brackets composed of a central C atom with one unshared electron pair and three single bonded H atoms to the left, right, and above the atom. Outside the brackets to the right is a superscript negative sign. Following a right pointing arrow is a structure with a central C atom with H atoms single bonded above, below, left and right. Following a plus sign is a structure with a central O atom with two unshared electron pairs and two H atoms connected with single bonds. ;
(c) CaO + SO 3 CaSO 4
This figure represents a chemical reaction using structural formulas. On the left, C a superscript 2 plus is just left of bracket O with four unshared electron pairs right bracket superscript 2 negative plus a structure with a central S atom to which two O atoms are single bonded at the left and right, and a single O atom is double bonded above. The two single bonded O atoms each have three unshared electron pairs and the double bonded O atom has two unshared electron pairs. Following a right pointing arrow is C a superscript 2 plus just left of a structure in brackets with a central S atom which has 4 O atoms single bonded at the left, above, below, and to the right. Each of the O atoms has three unshared electron pairs. Outside the brackets to the right is a superscript two negative. ;
(d) NH 4 + + C 2 H 5 O C 2 H 5 OH + NH 3
This figure represents a chemical reaction using structural formulas. A structure is shown in brackets on the left which is composed of a central N atom with four single bonded H atoms to the left, right, above, and below the atom. Outside the brackets to the right is a superscript plus sign. Following a plus sign, is another structure in brackets composed of a C atom with three single bonded H atoms above, below, and to the left. A second C atom is single bonded to the right. This C atom has H atoms single bonded above and below. To the right of the second C atom, an O atom is single bonded. This O atom has three unshared electron pairs. Outside the brackets to the right is a subperscript negative. Following a right pointing arrow is a structure composed of a C atom with three single bonded H atoms above, below, and to the left. A second C atom is single bonded to the right. This C atom has H atoms single bonded above and below. To the right of the second C atom, an O atom is single bonded. This O atom has two unshared electron pairs and an H atom single bonded to its right.

Got questions? Get instant answers now!

Calculate [ HgCl 4 2− ] in a solution prepared by adding 0.0200 mol of NaCl to 0.250 L of a 0.100- M HgCl 2 solution.

Got questions? Get instant answers now!

In a titration of cyanide ion, 28.72 mL of 0.0100 M AgNO 3 is added before precipitation begins. [The reaction of Ag + with CN goes to completion, producing the Ag ( CN ) 2 complex.] Precipitation of solid AgCN takes place when excess Ag + is added to the solution, above the amount needed to complete the formation of Ag ( CN ) 2 . How many grams of NaCN were in the original sample?

0.0281 g

Got questions? Get instant answers now!

What are the concentrations of Ag + , CN , and Ag ( CN ) 2 in a saturated solution of AgCN?

Got questions? Get instant answers now!

In dilute aqueous solution HF acts as a weak acid. However, pure liquid HF (boiling point = 19.5 °C) is a strong acid. In liquid HF, HNO 3 acts like a base and accepts protons. The acidity of liquid HF can be increased by adding one of several inorganic fluorides that are Lewis acids and accept F ion (for example, BF 3 or SbF 5 ). Write balanced chemical equations for the reaction of pure HNO 3 with pure HF and of pure HF with BF 3 .

HNO 3 ( l ) + HF ( l ) H 2 NO 3 + + F ; HF ( l ) + BF 3 ( g ) H + + BF 4

Got questions? Get instant answers now!

The simplest amino acid is glycine, H 2 NCH 2 CO 2 H. The common feature of amino acids is that they contain the functional groups: an amine group, –NH 2 , and a carboxylic acid group, –CO 2 H. An amino acid can function as either an acid or a base. For glycine, the acid strength of the carboxyl group is about the same as that of acetic acid, CH 3 CO 2 H, and the base strength of the amino group is slightly greater than that of ammonia, NH 3 .

(a) Write the Lewis structures of the ions that form when glycine is dissolved in 1 M HCl and in 1 M KOH.

(b) Write the Lewis structure of glycine when this amino acid is dissolved in water. (Hint: Consider the relative base strengths of the –NH 2 and CO 2 groups.)

Got questions? Get instant answers now!

Boric acid, H 3 BO 3 , is not a Brønsted-Lowry acid but a Lewis acid.

(a) Write an equation for its reaction with water.

(b) Predict the shape of the anion thus formed.

(c) What is the hybridization on the boron consistent with the shape you have predicted?

(a) H 3 BO 3 + H 2 O H 4 BO 4 + H + ; (b) The electronic and molecular shapes are the same—both tetrahedral. (c) The tetrahedral structure is consistent with sp 3 hybridization.

Got questions? Get instant answers now!

Questions & Answers

Modern Electronic Theory
Levi Reply
find the volume of oxygen produced from the electrolysis of acidified water of a current of a 2A was passed through the electrolysis of acidified water for 2 hours
Ngwu Reply
A group of atoms that are connected by chemical bounds
Valerie Reply
molecule
NARCOS_
the atoms are found in the shell, it is called atomic bond.
Andrew
what is molecules
Kelly Reply
what atoms
Simon
Moecules are groups of atoms
Adewole
What is collision theory
Isah Reply
hello guys am new here
Andrew Reply
what is the si unit for energy
enow Reply
joules
udoh
what is Charles law
Ogbu
how do mass of solvent be gram or kilogram ?
Yussuf Reply
by converting
Andrew
its a force a gas exerts on the wall of the container
udoh Reply
compressed it is
Andrew
what is gas pressure
Sandra Reply
the pressure is the amount of Gas that is compressed in the container. in other words because of the gas that is compressed in the container there is pressure on it.
Andrew
write the electron configuration for probium
Magano Reply
what is an accuracy
amadi Reply
what is it
Nhagn
accuracy has to do with speed
Emmanuel
accuracy is the movement of an object in a particular direction without any obstructions.
Andrew
what is titration curve
johnson Reply
a titration curve is the separation of a solvent in a curved direction.
Andrew
explain gaslaws
Felix Reply
explain accuracy
amadi
gas law states that the amount of molecule in the container is inversely proportional to the pressure.
Andrew
what is the functional group in this compound:CH3COCH2CH2-O-CH2
Obafemi Reply
this belongs to the Akane family. after going through this, I noticed the structural formula you gave was wrong. The answer to this is C5H10 heptane.
Andrew
Practice Key Terms 8

Get the best Chemistry course in your pocket!





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