{"id":3911,"date":"2026-03-27T15:00:20","date_gmt":"2026-03-27T19:00:20","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/?post_type=chapter&p=3911"},"modified":"2026-05-01T11:18:52","modified_gmt":"2026-05-01T15:18:52","slug":"quiz-solutions-4","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/chapter\/quiz-solutions-4\/","title":{"raw":"Quiz Solutions","rendered":"Quiz Solutions"},"content":{"raw":"
\r\n\r\n1. Indicate which combination of the following words\/phrases statements is correct.\r\n\r\nThe standard reduction potential is a measure of the tendency to accept electrons <\/span><\/span>and be reduced relative to the standard H+\/H2 electrode<\/span>.<\/span>\r\n\r\n2. Which of the following statements are true? Use T or F to indicate True or False.\r\n\r\n(i) An oxidizing agent accepts electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 F<\/span>\r\n(ii) A reducing agent accepts electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 F<\/span>\r\n(iii) A reducing agent accepts electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0F<\/span>\r\n(iv) A reducing agent loses electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0T<\/span>\r\n(v) An oxidizing agent accepts electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0T<\/span>\r\n(vi) An oxidizing agent loses electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0F<\/span>\r\n(vii) A reducing agent loses electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 F<\/span>\r\n(viii) An oxidizing agent loses electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0F<\/span>\r\n\r\n3.\u00a0Consider the following two couples.<\/span>\r\n
\r\n
\r\n\r\nMnO\u2084\u207b \/ Mn\u207a\u00b2 E\u00b0 = 1.51 V\r\nCO\u2082 \/H\u2082C\u2082O\u2084 E\u00b0 = -0.43 V\r\n\r\n<\/div>\r\n<\/div>\r\n
\r\n
\r\n\r\nCalculate the standard cell potential in volts.\r\n\r\n1.51 V - (-0.43 V) = 1.94 V<\/span>\r\n\r\n4. There are a number of nickel sulfides that are important in hydrometallurgy and pyrometallurgy. Relevant thermodynamic data are provided in the table below.<\/span>\r\n
\r\n
\r\n\r\n(a) There are four Ni(II) species (not including NiS). List them:\r\n\r\nNi+2\/NiOH+\/Ni(OH)2\/Ni(OH)3-<\/span>\r\n\r\n(b) Using hydrolysis states, what should be the order in which they appear from left to right on the Eh-pH diagram?\r\n\r\n*Ni+2*, *NiOH+*, *Ni(OH)2*, *Ni(OH)3-*<\/span>\r\n\r\n(c) We will ignore Ni(OH)3- . For the remaining three calculate the buffer pH values (vertical lines) that separate them on the diagram.\r\n\r\nNi+2\/NiOH+ pH: *9.916*<\/span>\r\n\r\nNiOH+\/Ni(OH)2 pH: *3.884*<\/span>\r\n\r\n(d) One of the Ni(II) species will not appear on the diagram under the given conditions. Indicate which one. What vertical line is required instead? Calculate its pH.\r\n\r\n*NiOH+*<\/span>\r\n\r\npH: *6.9\/6.90\/6.900*<\/span>\r\n\r\n5. Ni-S-H 2 O diagram: The sulfur-water diagram is available \u00a0in the course notes.\r\n\r\nWhich is the hydrolysis reactions for dissociation of NiS into Ni(II) and S(-II) species.\r\n\r\nNiS + 2H+<\/sup>\u00a0= Ni+2<\/sup>\u00a0+ H2<\/sub>S<\/span>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>","rendered":"
\n

1. Indicate which combination of the following words\/phrases statements is correct.<\/p>\n

The standard reduction potential is a measure of the tendency to accept electrons <\/span><\/span>and be reduced relative to the standard H+\/H2 electrode<\/span>.<\/span><\/p>\n

2. Which of the following statements are true? Use T or F to indicate True or False.<\/p>\n

(i) An oxidizing agent accepts electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 F<\/span>
\n(ii) A reducing agent accepts electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 F<\/span>
\n(iii) A reducing agent accepts electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0F<\/span>
\n(iv) A reducing agent loses electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0T<\/span>
\n(v) An oxidizing agent accepts electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0T<\/span>
\n(vi) An oxidizing agent loses electrons and gets oxidized\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0F<\/span>
\n(vii) A reducing agent loses electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 F<\/span>
\n(viii) An oxidizing agent loses electrons and gets reduced\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0F<\/span><\/p>\n

3.\u00a0Consider the following two couples.<\/span><\/p>\n

\n
\n

MnO\u2084\u207b \/ Mn\u207a\u00b2 E\u00b0 = 1.51 V
\nCO\u2082 \/H\u2082C\u2082O\u2084 E\u00b0 = -0.43 V<\/p>\n<\/div>\n<\/div>\n

\n
\n

Calculate the standard cell potential in volts.<\/p>\n

1.51 V – (-0.43 V) = 1.94 V<\/span><\/p>\n

4. There are a number of nickel sulfides that are important in hydrometallurgy and pyrometallurgy. Relevant thermodynamic data are provided in the table below.<\/span><\/p>\n

\n
\n

(a) There are four Ni(II) species (not including NiS). List them:<\/p>\n

Ni+2\/NiOH+\/Ni(OH)2\/Ni(OH)3-<\/span><\/p>\n

(b) Using hydrolysis states, what should be the order in which they appear from left to right on the Eh-pH diagram?<\/p>\n

*Ni+2*, *NiOH+*, *Ni(OH)2*, *Ni(OH)3-*<\/span><\/p>\n

(c) We will ignore Ni(OH)3- . For the remaining three calculate the buffer pH values (vertical lines) that separate them on the diagram.<\/p>\n

Ni+2\/NiOH+ pH: *9.916*<\/span><\/p>\n

NiOH+\/Ni(OH)2 pH: *3.884*<\/span><\/p>\n

(d) One of the Ni(II) species will not appear on the diagram under the given conditions. Indicate which one. What vertical line is required instead? Calculate its pH.<\/p>\n

*NiOH+*<\/span><\/p>\n

pH: *6.9\/6.90\/6.900*<\/span><\/p>\n

5. Ni-S-H 2 O diagram: The sulfur-water diagram is available \u00a0in the course notes.<\/p>\n

Which is the hydrolysis reactions for dissociation of NiS into Ni(II) and S(-II) species.<\/p>\n

NiS + 2H+<\/sup>\u00a0= Ni+2<\/sup>\u00a0+ H2<\/sub>S<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"author":2529,"menu_order":6,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-3911","chapter","type-chapter","status-publish","hentry"],"part":2174,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/chapters\/3911","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/wp\/v2\/users\/2529"}],"version-history":[{"count":4,"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/chapters\/3911\/revisions"}],"predecessor-version":[{"id":3948,"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/chapters\/3911\/revisions\/3948"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/parts\/2174"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/chapters\/3911\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/wp\/v2\/media?parent=3911"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/pressbooks\/v2\/chapter-type?post=3911"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/wp\/v2\/contributor?post=3911"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/hydrometallurgy\/wp-json\/wp\/v2\/license?post=3911"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}