General Chemistry Answers

Instant col‎d pac‎ks us‎ually em‎ploy the dis‎solution of am‎monium nitra‎te to w‎ork. Wh‎en the pa‎ck is twis‎ted, the in‎ner bag of wa‎ter ru‎ptures and so‎lid NH₄N‎O₃ is di‎ssolved in‎side the pa‎ck. This proc‎ess lead‎s to a tem‎perature dr‎op to ar‎ound 0°C. 

Wh‎ich of the foll‎owing is fa‎lse about the dissolution of ammonium nitrate?

NH₄‎NO_3(s) ⇌ NH‎₄⁺_(a‎_q) + NO‎₃^-_(a‎_q)

A. Thp‎e e‎nthal‎py of dis‎solution of NH‎₄NO₃ is en‎dothermic.

B. Low‎er en‎ergy is involv‎ed whe‎n w‎ater mole‎cules su‎rround the dissolv‎ed io‎ns th‎an when the wap‎ter mol‎ecules and am‎monium nitrate partic‎les are sepa‎rated.

C. The Gib‎bs fre‎e energy of disso‎lution of NH‎₄NO₃ is ne‎gative.

D. The intera‎ctions amon‎g sim‎ilar part‎icles or molec‎ules are wea‎ker than the int‎eractions amo‎ng the dissi‎milar parti‎cles or molec‎ules.

2.Consider a salt bridge voltaic cell represented by the following reaction:

Fe(s) + 2T1⁺(aq) ====> Fe²⁺(aq) + 2T1(s)

Choose the best answer from the choices in each part below:

a.What is the path of electron flow? Through the salt bridge, or

through the external circuit?

b.To which half-cell do the negative ions in the salt bridge move? The

manode, or the cathode?

c.Which metal is the electrode in the anode?

4.predict what reaction, if any, will occur when the following

species are mixed at standard conditions.

(Use Table 17.1 in the uploaded book chapter.)

a. Cr, Ni²⁺, C1^- (in acidic solution)

b.Sulfur is added to mercury.

c.Liquid bromine is added to an aqueous solution of sodium

chloride.

2.Consider a salt bridge voltaic cell represented by the following reaction:

Fe(s) + 2T1⁺(aq) ====> Fe²⁺(aq) + 2T1(s)

Choose the best answer from the choices in each part below:

a.What is the path of electron flow? Through the salt bridge, or

through the external circuit?

b.To which half-cell do the negative ions in the salt bridge move? The

manode, or the cathode?

c.Which metal is the electrode in the anode?

4.predict what reaction, if any, will occur when the following

species are mixed at standard conditions.

(Use Table 17.1 in the uploaded book chapter.)

a. Cr, Ni²⁺, C1^- (in acidic solution)

b.Sulfur is added to mercury.

c.Liquid bromine is added to an aqueous solution of sodium

chloride.

CHEM131 Chemistry for Engineers

Problem Set no. 1

1.

For the following half

-

reactions, answer the questions below.

Ce⁴⁺(aq) + e^- ====> Ce³ + (aq) E° = +1.61 V

Ag⁺(aq) + e^- ====>aq(s) E° = +0.80 V

Hg₂²⁺(aq) + 2e^- ====> 2Hg(I) E° = +0.80 V

Sn²⁺(aq) + 2e^- ====> Sn(s) E° = -0.14 V

Ni²⁺(aq) + 2e^- ====> Ni(s) E° = -0.24V

A1³⁺(aq) + 3e^- ====> A1(s) E° = -1.68V

a.Which is the weakest oxidizing agent?

b.Which is the strongest oxidizing agent?

c.Which is the strongest reducing agent?

d.Which is the weakest reducing agent?

e.Will Sn(s) reduce Ag+(aq) to Ag(s)?

f.Will Hg(l) reduce Sn2+(aq) to Sn(s)?

g.Which ion(s) can be reduced by Sn(s)?

h.Which metal(s) can be oxidized by Ag+(aq)?

of 1

How do you Calculate the pH of the solution formed when 45 mL of 0.1 M NaOH is added to 50 mL of 0.1 M CH3COOH. Kb= 5.5x10^-10

Determine the electronic configuration of palladium using spdf notation and orbital notation and identify if it is paramagnetic or diamagnetic

Determine the electronic configuration of potassium using spdf notation and orbital notation and identify if it is paramagnetic or diamagnetic

Determine the electronic configuration of oxygen using spdf notation and orbital notation and identify if it is paramagnetic or diamagnetic

Determine the electronic configuration of cerium using spdf notation and orbital notation and identify if it is paramagnetic or diamagnetic

A company uses H2 gas to generate electricity. They studied a smaller scale model

reaction to figure out the maximum amount of H2 gas that they can produce. For this

purpose, they used an alloy consisting of 95% Al by mass. The alloy has a density of 3.12

g/cm3

and they took a 0.875 cm3

small piece of alloy to react with 200 mL of 1.2 M solution

of HCl based on the given Al specific reaction. What is the maximum amount of H2 gas

that can be produced? What are the limiting and remaining reagents? How can they

increase the amount of H2 gas that they obtained?