(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

pH-value of everyday substances (cleaning agents, food) with Cobra SMARTsense

Article no: P7512569

Principle
In this experiment, students are introduced to the basics of acids and bases using everyday examples. In addition to practical work in the laboratory, the significance of different pH values is also discussed.

Tasks

Handling and, if necessary, calibrating a pH meter (Cobra SMARTsense pH)
Measuring the pH values of various acids and bases from everyday life, e.g. sparkling water, milk, lemonade or lemon juice
Classification of the pH values into the "acidic" or "alkaline" environment
Assignment of the environments to discrete pH value ranges

Learning objectives

The students will find out what a pH meter measures and how everyday chemicals react in water. In this context the terms "acidic" or "basic" environment are clarified and they are related to the concentration of protons (hydronium ions) in water.

Benefits

Digital learning thanks to the free measureAPP: display of measurement data on the tablet and option to export for evaluationÂ to a computer
Minimal preparation time: experimental literature available for students and teachers
Simple teaching and efficient learning when using the interactive experiment literature
Risk assessment available for students and teachers

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