Correct Answer:<\/strong> Explanation<\/strong> Boron trifluoride (BF\u2083)<\/strong> is a classic example of a Lewis acid. Boron, the central atom in BF\u2083, has only six electrons in its valence shell after forming three covalent bonds with fluorine atoms. This makes boron electron-deficient<\/em> and eager to accept a pair of electrons to complete its octet. Therefore, BF\u2083 acts as an electron pair acceptor<\/em>, which qualifies it as a Lewis acid. Despite the high electronegativity of the fluorine atoms, the molecule overall remains electron-deficient at the boron center. This deficiency is what drives BF\u2083 to behave as a Lewis acid when it interacts with electron-rich species.<\/p>\n\n\n\n Phosphorus trichloride (PCl\u2083)<\/strong>, on the other hand, has phosphorus as the central atom, surrounded by three chlorine atoms. Phosphorus has five valence electrons. In PCl\u2083, three of these electrons are used to form bonds with chlorine, leaving a lone pair of electrons on the phosphorus atom. This lone pair can be donated to other molecules or ions that are electron-deficient. Therefore, PCl\u2083 acts as an electron pair donor<\/em>, making it a Lewis base.<\/p>\n\n\n\n In summary, BF\u2083 lacks a complete octet and seeks to gain electrons, while PCl\u2083 has a lone pair available to share. Their behavior under the Lewis definition depends on whether they are looking to accept or donate electrons during a chemical reaction. This distinction classifies BF\u2083 as a Lewis acid and PCl\u2083 as a Lewis base.<\/p>\n\n\n\n Why BF3 is a Lewis acid but PCl3 is a Lewis base. The Correct Answer and Explanation is: Correct Answer:BF\u2083 is a Lewis acid because it can accept a lone pair of electrons. PCl\u2083 is a Lewis base because it can donate a lone pair of electrons. ExplanationThe terms Lewis acid and Lewis base are […]<\/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-37029","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/37029","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=37029"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/37029\/revisions"}],"predecessor-version":[{"id":37031,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/37029\/revisions\/37031"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=37029"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=37029"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=37029"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
BF\u2083 is a Lewis acid because it can accept a lone pair of electrons. PCl\u2083 is a Lewis base because it can donate a lone pair of electrons.<\/p>\n\n\n\n
The terms Lewis acid<\/em> and Lewis base<\/em> are defined based on the movement of electron pairs. A Lewis acid is a substance that can accept a pair of electrons, while a Lewis base is one that can donate a pair of electrons.<\/p>\n\n\n\n![\"\"](\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner8-843.jpeg\")
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