{"id":618,"date":"2024-06-19T09:10:15","date_gmt":"2024-06-19T06:10:15","guid":{"rendered":"https:\/\/sisu.ut.ee\/measurement\/self-test-9-b\/"},"modified":"2024-06-19T09:10:15","modified_gmt":"2024-06-19T06:10:15","slug":"self-test-9-b","status":"publish","type":"page","link":"https:\/\/sisu.ut.ee\/measurement\/self-test-9-b\/","title":{"rendered":"Self-test 9 B"},"content":{"rendered":"<div id=\"watupro_quiz\" class=\"quiz-area single-page-quiz\">\n<p id=\"submittingExam26\" style=\"display:none;text-align:center;\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/sisu.ut.ee\/wp-content\/plugins\/watupro\/img\/loading.gif\" width=\"16\" height=\"16\"><\/p>\n\n\n\n<form action=\"\" method=\"post\" class=\"quiz-form\" id=\"quiz-26\" enctype=\"multipart\/form-data\">\n<div class=\"watu-question \" id=\"question-1\" style=\";\"><div id=\"questionWrap-1\" class=\"   watupro-question-id-104\">\n\t\t\t<div class=\"question-content\"><p>Standard substance (KIO<sub>3<\/sub>, see the picture) solution was prepared by weighing 0.21500 g of KIO<sub>3<\/sub> into the 100 ml volumetric flask (see the picture) in the laboratory, which temperature didn\u2019t differ from 20\u00b0C more than \u00b13\u00b0C. Uncertainty of filling the flask is not higher than \u00b11 drop (the volume of the drop is approximately 0.03 ml). The repeatability standard deviation of the balance used (with 5 decimal places) was 0.00021 g. The uncertainty due to calibration, drift and linearity of the balance can be considered insignificant. What is the concentration of the solution (unit g\/l) and its combined standard uncertainty?\u00a0Result and uncertainty must be presented with four decimal places and rounding must be done for the last digit.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"720\" height=\"537\" class=\"alignnone wp-image-220\" style=\"display: block; margin-left: auto; margin-right: auto;\" title=\"test7-1-c.png\" src=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-1-c.png\" alt=\"test7-1-c.png\" srcset=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-1-c.png 720w, https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-1-c-300x224.png 300w\" sizes=\"auto, (max-width: 720px) 100vw, 720px\"><\/p>\n<p><span style=\"line-height: 1.6em;\">Find the acidity of the investigated liquid and\u00a0<\/span><span style=\"line-height: 1.6em;\">the standard uncertainty.\u00a0<\/span><\/p>\n<div class=\"accordion-block mb-3\">\n<div id=\"accordion-accordion-6683c25b12875\" class=\"accordion \">\n<div class=\"accordion-item accordion-item--white\">\n<h3 id=\"accordion-6683c25b12875-heading-1\" class=\"accordion-header\"><button class=\"accordion-button collapsed\" type=\"button\" data-bs-toggle=\"collapse\" data-bs-target=\"#accordion-6683c25b12875-collapse-1\" aria-expanded=\"false\" aria-controls=\"accordion-6683c25b12875-collapse-1\">Clue 1<\/button><\/h3>\n<div id=\"accordion-6683c25b12875-collapse-1\" class=\"accordion-collapse collapse\" aria-labelledby=\"accordion-6683c25b12875-heading-1\">\n<div class=\"accordion-body\">\n<div>Uncertainty components of <em>c<\/em>(KIO<sub>3<\/sub>) are: purity of the KIO<sub>3 <\/sub>(<em>u<\/em><sub>purity<\/sub>), mass of the KIO<sub>3<\/sub> (<em>u<\/em><sub>mass<\/sub>) and volume of the solution (<em>u<\/em><sub>volume<\/sub>). Mathematical model:<br>\n<img loading=\"lazy\" decoding=\"async\" width=\"345\" height=\"56\" class=\"alignnone wp-image-221\" title=\"test7-clue1.png\" src=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-clue1.png\" alt=\"test7-clue1.png\" srcset=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-clue1.png 345w, https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-clue1-300x49.png 300w\" sizes=\"auto, (max-width: 345px) 100vw, 345px\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"accordion-block mb-3\">\n<div id=\"accordion-accordion-6683c25b128752\" class=\"accordion \">\n<div class=\"accordion-item accordion-item--white\">\n<h3 id=\"accordion-6683c25b128752-heading-1\" class=\"accordion-header\"><button class=\"accordion-button collapsed\" type=\"button\" data-bs-toggle=\"collapse\" data-bs-target=\"#accordion-6683c25b128752-collapse-1\" aria-expanded=\"false\" aria-controls=\"accordion-6683c25b128752-collapse-2\">Clue 2<\/button><\/h3>\n<div id=\"accordion-6683c25b128752-collapse-1\" class=\"accordion-collapse collapse\" aria-labelledby=\"accordion-6683c25b128752-heading-1\">\n<div class=\"accordion-body\">\n<div>Actual purity is assumed to be exactly between maximum and minimum purity with the rectangular distribution. Uncertainty of the mass has two main components: repeatability and rounding of the digital reading. Uncertainty of the solution volume (<em>u<\/em><sub>volume<\/sub>) has three main uncertainty sources: calibration of the flask, filling of the flask and temperature changes.<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"accordion-block mb-3\">\n<div id=\"accordion-accordion-6683c25b128753\" class=\"accordion \">\n<div class=\"accordion-item accordion-item--white\">\n<h3 id=\"accordion-6683c25b128753-heading-1\" class=\"accordion-header\"><button class=\"accordion-button collapsed\" type=\"button\" data-bs-toggle=\"collapse\" data-bs-target=\"#accordion-6683c25b128753-collapse-1\" aria-expanded=\"false\" aria-controls=\"accordion-6683c25b128753-collapse-1\">Clue 3<\/button><\/h3>\n<div id=\"accordion-6683c25b128753-collapse-1\" class=\"accordion-collapse collapse\" aria-labelledby=\"accordion-6683c25b128753-heading-1\">\n<div class=\"accordion-body\">\n<div>The flask was not calibrated in the laboratory, so we have to use data given by the manufacturer. As it is seen from the picture, it is \u00b10.1 ml and the calibration was done at 20\u00b0C. Experiment was made at the temperature (20 \u00b1 3) \u00b0C and uncertainty caused by the temperature changes is calculated according to eq\u00a0<img loading=\"lazy\" decoding=\"async\" width=\"167\" height=\"58\" class=\"alignnone wp-image-222\" style=\"vertical-align: middle;\" title=\"test7-clue3.png\" src=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/18\/test7-clue3.png\" alt=\"test7-clue3.png\">where\u00a0<em>\u03b3<\/em><sub>W<\/sub>=2.1\u00b710<sup><span style=\"font-size: xx-small;\"><span style=\"line-height: 0px;\">-4<\/span><\/span><\/sup>\u00a0\u00b71\/<sup>0<\/sup>C.<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"accordion-block mb-3\">\n<div id=\"accordion-accordion-6683c25b128754\" class=\"accordion \">\n<div class=\"accordion-item accordion-item--white\">\n<h3 id=\"accordion-6683c25b128754-heading-1\" class=\"accordion-header\"><button class=\"accordion-button collapsed\" type=\"button\" data-bs-toggle=\"collapse\" data-bs-target=\"#accordion-6683c25b128754-collapse-1\" aria-expanded=\"false\" aria-controls=\"accordion-6683c25b128754-collapse-1\">Clue 4<\/button><\/h3>\n<div id=\"accordion-6683c25b128754-collapse-1\" class=\"accordion-collapse collapse\" aria-labelledby=\"accordion-6683c25b128754-heading-1\">\n<div class=\"accordion-body\">\n<div>All contributing uncertainties should be expressed in the same units. In case of model that includes only multiplications and divisions is the correct way is to calculate the relative (unitless) standard uncertainties and then to combine those. Then you should multiply the relative uncertainty with the value of the result and you get the combined standard uncertainty with the same unit as the result.<\/div>\n<div><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"accordion\" class=\"accordion\">\n<p><strong>The concentration (unit g\/l) of the solution \u00a0is:<\/strong><\/p>\n<p>c(KIO<sub>3<\/sub>) = <input type=\"text\" size=\"10\" name=\"gap_104_1\" class=\"watupro-gap answer answerof-104\" value=\"\"><\/p>\n<p><strong>The combined standard uncertainty of the KIO<sub>3<\/sub> solution concentration is:<\/strong><\/p>\n<p><em>u<\/em><sub>c<\/sub>(<em>c<\/em>(KIO<sub>3<\/sub>))= <input type=\"text\" size=\"10\" name=\"gap_104_2\" class=\"watupro-gap answer answerof-104\" value=\"\"><\/p>\n<\/div>\n<input type=\"hidden\" name=\"question_id[]\" id=\"qID_1\" value=\"104\" class=\"watupro-question-id\"><input type=\"hidden\" id=\"answerType104\" class=\"answerTypeCnt1\" value=\"gaps\"><!-- end question-content--><\/div><!-- end questionWrap--><\/div><\/div><div style=\"display:none\" id=\"question-2\">\n\t<div class=\"question-content\">\n\t\t<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/sisu.ut.ee\/wp-content\/plugins\/watupro\/img\/loading.gif\" width=\"16\" height=\"16\" alt=\"Loading...\" title=\"Loading...\">\u00a0Loading...\t<\/div>\n<\/div>\n\n<br>\n\t\n\t\t\t<div class=\"watupro_buttons flex \" id=\"watuPROButtons26\">\n\t\t  <div id=\"prev-question\" style=\"display:none;\"><input type=\"button\" value=\"&lt; Previous\" onclick=\"WatuPRO.nextQuestion(event, 'previous');\"><\/div>\t\t  \t\t  \t\t   \n\t\t   \t  \t\t<div><input type=\"button\" name=\"action\" class=\"watupro-submit-button\" onclick=\"WatuPRO.submitResult(event)\" id=\"action-button\" value=\"View Results\">\n\t\t<\/div>\n\t\t<\/div>\n\t\t\n\t<input type=\"hidden\" name=\"quiz_id\" value=\"26\" id=\"watuPROExamID\">\n\t<input type=\"hidden\" name=\"start_time\" id=\"startTime\" value=\"2026-04-11 16:22:45\">\n\t<input type=\"hidden\" name=\"start_timestamp\" id=\"startTimeStamp\" value=\"1775924565\">\n\t<input type=\"hidden\" name=\"question_ids\" value=\"\">\n\t<input type=\"hidden\" name=\"watupro_questions\" value=\"104:\">\n\t<input type=\"hidden\" name=\"no_ajax\" value=\"0\">\t\t\t<\/form>\n\t<p>\u00a0<\/p>\n<\/div>\n\n<script type=\"text\/javascript\">\n\/\/jQuery(document).ready(function(){\ndocument.addEventListener(\"DOMContentLoaded\", function(event) { \t\nvar question_ids = \"104\";\nWatuPROSettings[26] = {};\nWatuPRO.qArr = question_ids.split(',');\nWatuPRO.exam_id = 26;\t    \nWatuPRO.post_id = 618;\nWatuPRO.store_progress = 0;\nWatuPRO.curCatPage = 1;\nWatuPRO.requiredIDs=\"0\".split(\",\");\nWatuPRO.hAppID = \"0.30855400 1775913765\";\nvar url = \"https:\/\/sisu.ut.ee\/wp-content\/plugins\/watupro\/show_exam.php\";\nWatuPRO.examMode = 1;\nWatuPRO.siteURL=\"https:\/\/sisu.ut.ee\/measurement\/wp-admin\/admin-ajax.php\";\nWatuPRO.emailIsNotRequired = 0;\nWatuPRO.perDecade = 10;\nWatuPROIntel.init(26);\nWatuPRO.inCategoryPages=1;});    \t \n<\/script>\n\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":280,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"class_list":["post-618","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages\/618","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/users\/280"}],"replies":[{"embeddable":true,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/comments?post=618"}],"version-history":[{"count":0,"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/pages\/618\/revisions"}],"wp:attachment":[{"href":"https:\/\/sisu.ut.ee\/measurement\/wp-json\/wp\/v2\/media?parent=618"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}