To solve this, we can use the formula for molarity, which is:M=moles of solutevolume of solution in litersM = \\frac{\\text{moles of solute}}{\\text{volume of solution in liters}}M=volume of solution in litersmoles of solute\u200b<\/p>\n\n\n\n
Where:<\/p>\n\n\n\n
- \n
- MMM is the molarity (moles per liter),<\/li>\n\n\n\n
- The volume of the solution is given in liters,<\/li>\n\n\n\n
- The moles of solute can be converted into grams using the molar mass of sodium hydroxide (NaOH).<\/li>\n<\/ul>\n\n\n\n
Step 1: Calculate moles of NaOH needed<\/h3>\n\n\n\n
We are given:<\/p>\n\n\n\n
- \n
- Molarity (M) = 0.125 M,<\/li>\n\n\n\n
- Volume of solution (V) = 100.0 mL = 0.1000 L (since 1 L = 1000 mL).<\/li>\n<\/ul>\n\n\n\n
We can calculate the moles of NaOH using the formula for molarity:moles of NaOH=M\u00d7V\\text{moles of NaOH} = M \\times Vmoles of NaOH=M\u00d7Vmoles of NaOH=0.125\u2009mol\/L\u00d70.1000\u2009L\\text{moles of NaOH} = 0.125 \\, \\text{mol\/L} \\times 0.1000 \\, \\text{L}moles of NaOH=0.125mol\/L\u00d70.1000Lmoles of NaOH=0.0125\u2009mol\\text{moles of NaOH} = 0.0125 \\, \\text{mol}moles of NaOH=0.0125mol<\/p>\n\n\n\n
Step 2: Convert moles of NaOH to grams<\/h3>\n\n\n\n
Next, we convert the moles of NaOH to grams using the molar mass of NaOH, which is 40.0 g\/mol.mass of NaOH=moles of NaOH\u00d7molar mass of NaOH\\text{mass of NaOH} = \\text{moles of NaOH} \\times \\text{molar mass of NaOH}mass of NaOH=moles of NaOH\u00d7molar mass of NaOHmass of NaOH=0.0125\u2009mol\u00d740.0\u2009g\/mol\\text{mass of NaOH} = 0.0125 \\, \\text{mol} \\times 40.0 \\, \\text{g\/mol}mass of NaOH=0.0125mol\u00d740.0g\/molmass of NaOH=0.500\u2009g\\text{mass of NaOH} = 0.500 \\, \\text{g}mass of NaOH=0.500g<\/p>\n\n\n\n
Final Answer:<\/h3>\n\n\n\n
The mass of NaOH needed to prepare 100.0 mL of a 0.125 M NaOH solution is 0.500 g<\/strong>.<\/p>\n\n\n\n
So, the correct answer is D. 0.500 g<\/strong>.<\/p>\n\n\n\n
![\"\"](\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/07\/learnexams-banner5-199.jpeg\")
<\/figure>\n","protected":false},"excerpt":{"rendered":"‘What mass of sodium hydroxide (NaOH; molar mass 40.0 g mol-I) is needed to make 100.0 mL of a 0.125 M NaOH solution? 0 A. 5.00 g B. 0.0500 g C.3.13 g D.0.500 g’ The Correct Answer and Explanation is: To solve this, we can use the formula for molarity, which is:M=moles of solutevolume of solution in litersM = \\frac{\\text{moles of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-46941","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/46941","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=46941"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/46941\/revisions"}],"predecessor-version":[{"id":46947,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/46941\/revisions\/46947"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=46941"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=46941"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=46941"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}