(function () { function textOf(el) { return (el && el.textContent || "").replace(/\s+/g, " ").trim(); } function resolveItemUrl() { var match = window.location.search.match(/[?&]item=(\d+)/); if (!match) { return null; } return window.location.origin + "/a-" + match[1] + "/"; } function loadAccordion() { var url = resolveItemUrl(); if (!url) { return Promise.resolve(null); } return new Promise(function (resolve, reject) { var xhr = new XMLHttpRequest(); xhr.open("GET", url, true); xhr.onload = function () { if (xhr.status < 200 || xhr.status >= 400) { reject(new Error("item page " + xhr.status)); return; } var doc = new DOMParser().parseFromString(xhr.responseText, "text/html"); resolve(doc.querySelector(".phywe-item-accordion")); }; xhr.onerror = function () { reject(new Error("item page network error")); }; xhr.send(); }); } function parseItemBlocks(scope, withQuantity) { if (!scope) { return []; } var rows = scope.querySelectorAll(".itemslist .row.itemblocks"); var items = []; for (var i = 0; i < rows.length; i++) { var cols = rows[i].children; if (!cols.length) { continue; } var nameLink = cols[0].querySelector("a"); var numberLink = cols[1] ? cols[1].querySelector("a") : null; var item = { name: textOf(nameLink || cols[0]), mappedTo: textOf(numberLink) }; if (withQuantity && cols[2]) { var qty = parseInt(textOf(cols[2]).replace(/[^\d]/g, ""), 10); item.quantity = isNaN(qty) ? textOf(cols[2]) : String(qty); } if (item.name) { items.push(item); } } return items; } function fillTable(tableId, items, withQuantity) { var table = document.getElementById(tableId); if (!table || !items.length) { return; } var tbody = table.querySelector("tbody"); for (var i = 0; i < items.length; i++) { var tr = document.createElement("tr"); var nameTd = document.createElement("td"); nameTd.style.width = "80%"; nameTd.textContent = items[i].name; tr.appendChild(nameTd); var numberTd = document.createElement("td"); numberTd.textContent = items[i].mappedTo; tr.appendChild(numberTd); if (withQuantity) { var qtyTd = document.createElement("td"); qtyTd.textContent = items[i].quantity || ""; tr.appendChild(qtyTd); } tbody.appendChild(tr); } var wrapper = table.parentElement; while (wrapper && wrapper.className.indexOf("printtablediv") === -1) { wrapper = wrapper.parentElement; } if (wrapper) { wrapper.style.display = ""; } } function stepTitle(stepEl) { if (!stepEl) { return ""; } var titleEl = stepEl.querySelector(".card-header button div") || stepEl.querySelector(".card-header button"); return textOf(titleEl); } function setHeadline(tableId, title) { var headline = document.querySelector("#" + tableId + " .printtableheadline"); if (headline && title) { headline.textContent = title; } } function parseMedia(scope) { if (!scope) { return []; } var rows = scope.querySelectorAll(".itemslist .row.itemblocks"); var items = []; for (var i = 0; i < rows.length; i++) { var cols = rows[i].children; if (!cols.length) { continue; } var nameLink = cols[0].querySelector("a"); var fileLink = cols[1] ? cols[1].querySelector("a") : null; var item = { name: textOf(nameLink || cols[0]), mappedTo: textOf(fileLink || cols[1]), quantity: cols[2] ? textOf(cols[2]) : "" }; if (item.name) { items.push(item); } } return items; } function fillFromAccordion(accordion) { if (!accordion) { return; } var versucheStep = accordion.querySelector('[data-step="versuche"]'); var versuche = parseItemBlocks(versucheStep, false); setHeadline("print-versuche", stepTitle(versucheStep)); fillTable("print-versuche", versuche, false); var lieferumfangStep = accordion.querySelector('[data-step="lieferumfang"]'); var lieferumfang = parseItemBlocks(lieferumfangStep, true); fillTable("print-lieferumfang", lieferumfang, true); var zubehoer = accordion.querySelector('[data-step="zubehoer"]'); var sections = zubehoer ? zubehoer.querySelectorAll(".card-body") : []; var notwendig = []; var empfohlen = []; for (var i = 0; i < sections.length; i++) { var items = parseItemBlocks(sections[i], false); if (sections[i].querySelector(".text-red, .icon-warning-black")) { notwendig = items; } else if (sections[i].querySelector(".text-green, .icon-Mehrwert_black")) { empfohlen = items; } } fillTable("print-zubehoer-notwendig", notwendig, false); fillTable("print-zubehoer-empfohlen", empfohlen, false); var mediaStep = accordion.querySelector('[data-step="media"]'); var media = parseMedia(mediaStep); setHeadline("print-media", stepTitle(mediaStep)); fillTable("print-media", media, true); } function start() { var itemUrl = resolveItemUrl(); if (!itemUrl) { setTimeout(function () { window.print(); }, 2000); return; } loadAccordion() .then(function (accordion) { fillFromAccordion(accordion); }) .catch(function (err) { if (window.console && console.warn) { console.warn("Accordion konnte nicht geladen werden:", resolveItemUrl(), err); } }) .then(function () { setTimeout(function () { window.print(); }, 500); }); } if (document.readyState === "loading") { document.addEventListener("DOMContentLoaded", start); } else { start(); } })();
 

Technical data


Reducing properties of glucose

Article no: P7186900
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> Unknown

Principle
The aldehyde groups in glucose can be detected with silver nitrate, Fehling's solution and methylene blue. Glucose acts as a strong reducing agent in basic solutions. Glucose is thereby reduced to gluconic acid. Glass mirrors can be prepared with ammonical silver nitrate and glucose.The aldehyde group is responsible for the reducing properties of glucose. The reaction first takes place in hot alkaline solution. The chain type structure with the reactive acetaldehyde groups is formed from the stable hemiacetal form of glucose under these conditions.

 

Learning objectives

  • Glucose is a reducing agent
  • Detection methods for glucose

 

Benefits

  • Easy teaching and efficient learning by using interactive experimentation PHYWE-Software
  • Experiment is part of a complete solution set with experiments for the topic Food Chemistry matched with international curriculum: all topics are covered

 


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