{"id":223199,"date":"2025-06-01T10:34:05","date_gmt":"2025-06-01T10:34:05","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=223199"},"modified":"2025-06-01T10:34:07","modified_gmt":"2025-06-01T10:34:07","slug":"name-date-laboratory-instructor-desk-unknown-no-07-report-sheet-abbreviated-qualitative-analysis-scheme-experiment-32","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/01\/name-date-laboratory-instructor-desk-unknown-no-07-report-sheet-abbreviated-qualitative-analysis-scheme-experiment-32\/","title":{"rendered":"Name Date Laboratory Instructor Desk Unknown no #07 REPORT SHEET Abbreviated Qualitative Analysis Scheme EXPERIMENT 32"},"content":{"rendered":"\n

Name Date Laboratory Instructor Desk Unknown no #07 REPORT SHEET Abbreviated Qualitative Analysis Scheme EXPERIMENT 32 PART I: GROUP 1 CATIONS Record the reagent used in each step, your observations, and the equations for each precipitation reaction. Procedure Reagent Observations Equations Mark (+) if observed in unknown G1-1 KSCN yellow + G1-2 NH
dark grey + G1-3 HNO
Clear Cations in group 1 unknown
Name Date Laboratory Instructor Desk Unknown no #07 REPORT SHEET Abbreviated Qualitative Analysis Scheme EXPERIMENT 32 PART I: GROUP 1 CATIONS Record the reagent used in each step, your observations, and the equations for each precipitation reaction. Procedure Reagent Observations Equations Mark (+) if observed in unknown G1-1 KSCN yellow + G1-2 NH
dark grey + G1-3 HNO
Clear Cations in group 1 unknown<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

REPORT SHEET: Abbreviated Qualitative Analysis Scheme<\/strong><\/h3>\n\n\n\n

EXPERIMENT 32 \u2013 PART I: GROUP 1 CATIONS<\/strong>
Unknown No. 07<\/strong><\/p>\n\n\n\n

\n\n\n\n
Procedure<\/strong><\/th>Reagent<\/strong><\/th>Observations<\/strong><\/th>Equations<\/strong><\/th>Observed in Unknown<\/strong><\/th><\/tr><\/thead>
G1-1<\/td>KSCN<\/td>Yellow precipitate forms<\/td>Fe\u00b3\u207a + SCN\u207b \u2192 [Fe(SCN)]\u00b2\u207a (blood red or yellow complex)<\/td>\u2714\ufe0f<\/td><\/tr>
G1-2<\/td>NH\u2084OH<\/td>Dark grey precipitate<\/td>Ag\u207a + NH\u2083 + H\u2082O \u2192 [Ag(NH\u2083)\u2082]\u207a (soluble), then \u2192 Ag \u2193<\/td>\u2714\ufe0f<\/td><\/tr>
G1-3<\/td>HNO\u2083<\/td>Clear solution<\/td>PbCl\u2082 dissolves in hot water, no precipitate seen<\/td>\u2714\ufe0f<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Cations in Group 1 Unknown<\/strong>:
Fe\u00b3\u207a, Ag\u207a, Pb\u00b2\u207a<\/strong><\/p>\n\n\n\n

\n\n\n\n

Explanation<\/strong><\/h3>\n\n\n\n

In qualitative inorganic analysis, Group 1 cations<\/strong> typically include Ag\u207a (silver), Pb\u00b2\u207a (lead), and Hg\u2082\u00b2\u207a (mercury(I))<\/strong>, but in some schemes, Fe\u00b3\u207a (iron(III))<\/strong> may also be tested early due to distinctive reactions. The goal is to identify which of these cations are present in an unknown sample (#07), based on their reactions with specific reagents.<\/p>\n\n\n\n

    \n
  1. G1-1 (KSCN Test):<\/strong>
    When potassium thiocyanate (KSCN) is added, the formation of a yellow to blood-red complex<\/strong> indicates the presence of Fe\u00b3\u207a<\/strong>. The thiocyanate ion reacts with ferric ion to form the [Fe(SCN)]\u00b2\u207a complex. The appearance of a yellow precipitate confirms Fe\u00b3\u207a<\/strong> in the unknown.<\/li>\n\n\n\n
  2. G1-2 (Ammonia Test):<\/strong>
    Ammonium hydroxide (NH\u2084OH) reacts with Ag\u207a<\/strong> ions to form initially a brown precipitate of Ag\u2082O or AgOH, which may turn dark grey<\/strong> due to the reduction of silver ions to metallic silver. The dark grey precipitate confirms the presence of Ag\u207a<\/strong>.<\/li>\n\n\n\n
  3. G1-3 (Nitric Acid Test):<\/strong>
    When nitric acid (HNO\u2083) is added, it dissolves any basic precipitates like AgOH or Pb(OH)\u2082. If the solution becomes clear<\/strong>, this suggests dissolution of a lead or silver compound. Since the precipitate dissolves, Pb\u00b2\u207a<\/strong> is likely present as PbCl\u2082, which is soluble in hot water and does not precipitate in acidic conditions.<\/li>\n<\/ol>\n\n\n\n

    Based on the observations at each step, Fe\u00b3\u207a, Ag\u207a, and Pb\u00b2\u207a<\/strong> are all indicated in the unknown. This experiment demonstrates how systematic qualitative analysis allows the identification of multiple ions based on selective precipitation and color changes.<\/p>\n\n\n\n

    \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

    Name Date Laboratory Instructor Desk Unknown no #07 REPORT SHEET Abbreviated Qualitative Analysis Scheme EXPERIMENT 32 PART I: GROUP 1 CATIONS Record the reagent used in each step, your observations, and the equations for each precipitation reaction. Procedure Reagent Observations Equations Mark (+) if observed in unknown G1-1 KSCN yellow + G1-2 NHdark grey + […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-223199","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/223199","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=223199"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/223199\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=223199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=223199"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=223199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}