{"id":247194,"date":"2025-07-07T15:18:50","date_gmt":"2025-07-07T15:18:50","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=247194"},"modified":"2025-07-07T15:18:52","modified_gmt":"2025-07-07T15:18:52","slug":"the-following-table-lists-the-names-of-some-common-pesticides-their-solubility-in-water-their-log-kow-and-their-ld50","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/07\/the-following-table-lists-the-names-of-some-common-pesticides-their-solubility-in-water-their-log-kow-and-their-ld50\/","title":{"rendered":"The following table lists the names of some common pesticides, their solubility in water, their Log Kow, and their LD50."},"content":{"rendered":"\n


The following table lists the names of some common pesticides, their solubility in water, their Log Kow, and their LD50. Pesticide Solubility in H2O (ppm) Log Kow LD50 (mg\/kg) HCB 0.0062 5.3 3500 DDT 0.0034 3.9 – 6.2 115 Toxaphene 0.20 6.9 – 7.5 700 Dieldrin 6.9 – 7.5 700 Mirex 0.20 6.9 – 7.5 700 Malathion 145 2.9 1375 Parathion 3.8 3.6 – 13 Atrazine 2.2 2.7 1870 The range of reported data in Log Kow and LD50 are due to different sources. HCB: hexachlorobenzene DDT: dichlorodiphenyltrichloroethane Based on this information, some statements are given below: (1) DDT is the least water soluble among the listed organic pesticides; therefore, it is the most toxic pesticide. (2) LD50 is an experimental parameter used to estimate the toxicity of a chemical compound. (3) Because the pesticide Mirex has the highest Log Kow, it is the most toxic chemical compound. (4) In general, when its Log Kow is high, the organic compound is less water soluble. Which of the above statement(s) is (are) correct? (A) (1) (B) (2) & (4) (C) (1), (2) & (4) (D) (1) & (3)<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

The correct answer is (B) (2) & (4)<\/strong>.<\/p>\n\n\n\n

Here’s an explanation of each statement:<\/h3>\n\n\n\n
    \n
  1. Statement (1):<\/strong>“DDT is the least water soluble among the listed organic pesticides; therefore, it is the most toxic pesticide.”<\/em>\n
      \n
    • Incorrect.<\/strong> While DDT has low solubility in water (0.0034 ppm), it is not the most toxic pesticide in this list. Its LD50 (115 mg\/kg) is lower than that of some other pesticides like Malathion (1375 mg\/kg) and Atrazine (1870 mg\/kg). Toxicity, measured by LD50, is not directly correlated to solubility in water. The solubility of a pesticide influences its ability to persist in water and enter aquatic organisms, but it is not a direct indicator of toxicity. DDT is not the most toxic here.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
    • Statement (2):<\/strong>“LD50 is an experimental parameter used to estimate the toxicity of a chemical compound.”<\/em>\n
        \n
      • Correct.<\/strong> LD50 (lethal dose for 50% of the test population) is indeed an experimental value used to estimate the acute toxicity of a substance. It provides an idea of how much of a substance is required to cause lethal effects in 50% of the test population (usually animals). It is widely used in toxicology to assess the harmful effects of chemicals.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • Statement (3):<\/strong>“Because the pesticide Mirex has the highest Log Kow, it is the most toxic chemical compound.”<\/em>\n
          \n
        • Incorrect.<\/strong> While Mirex has a high Log Kow (6.9 – 7.5), which indicates that it is highly lipophilic (fat-soluble), this does not necessarily correlate with toxicity. Mirex’s toxicity (LD50 = 700 mg\/kg) is not the highest in the table. Toxaphene also has a similar Log Kow range but has a lower LD50 of 700 mg\/kg. High Log Kow does not equate to the highest toxicity.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
        • Statement (4):<\/strong>“In general, when its Log Kow is high, the organic compound is less water soluble.”<\/em>\n
            \n
          • Correct.<\/strong> Log Kow measures the ratio of a compound’s concentration in octanol (a non-polar solvent) to its concentration in water (a polar solvent). A higher Log Kow suggests that the compound is more lipophilic (fat-soluble) and thus less soluble in water. This is a general rule observed in the pesticides listed: higher Log Kow values correspond with lower water solubility.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n

            Conclusion:<\/h3>\n\n\n\n

            Statements (2) and (4) are correct. While high Log Kow typically indicates lower water solubility, it does not necessarily mean higher toxicity. The solubility of a pesticide and its toxicity are related, but not in a simple cause-effect manner, as shown by DDT’s lower toxicity compared to other compounds with similar Log Kow values.<\/p>\n\n\n\n

            \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

            The following table lists the names of some common pesticides, their solubility in water, their Log Kow, and their LD50. Pesticide Solubility in H2O (ppm) Log Kow LD50 (mg\/kg) HCB 0.0062 5.3 3500 DDT 0.0034 3.9 – 6.2 115 Toxaphene 0.20 6.9 – 7.5 700 Dieldrin 6.9 – 7.5 700 Mirex 0.20 6.9 – 7.5 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-247194","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/247194","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=247194"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/247194\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=247194"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=247194"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=247194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}