\u0110\u1ec3 gi\u1eef cho kh\u00f4ng kh\u00ed kh\u00f4 r\u00e1o ng\u01b0\u1eddi ta d\u00f9ng nh\u1eefng bi\u1ec7n ph\u00e1p trong \u0111\u00f3 c\u00f3 bi\u1ec7n ph\u00e1p d\u00f9ng ch\u1ea5t h\u00fat \u1ea9m. Ch\u1ea5t h\u00fat \u1ea9m l\u00e0 nh\u1eefng ch\u1ea5t c\u00f3 kh\u1ea3 n\u0103ng h\u1ea5p th\u1ee5 m\u1ea1nh h\u01a1i n\u01b0\u1edbc trong kh\u00f4ng kh\u00ed. Ng\u01b0\u1eddi Trung Qu\u1ed1c th\u1eddi c\u1ed5 \u0111\u1ea1i bi\u1ebft c\u00e1ch d\u00f9ng v\u00f4i s\u1ed1ng \u0111\u1ec3 b\u1ea3o qu\u1ea3n d\u01b0\u1ee3c li\u1ec7u, ch\u00e8 l\u00e0 nh\u1eefng s\u1ea3n ph\u1ea9m c\u1ea7n gi\u1eef \u1edf tr\u1ea1ng th\u00e1i kh\u00f4 r\u00e1o, v\u00ec ch\u00fang d\u1ec5 h\u1ea5p th\u1ee5 h\u01a1i n\u01b0\u1edbc v\u00e0 s\u1ebd h\u01b0 h\u1ecfng do h\u01a1i \u1ea9m. Ng\u00e0y nay \u1edf c\u00e1c ph\u00f2ng th\u00ed nghi\u1ec7m, ng\u01b0\u1eddi ta hay d\u00f9ng axit sunfuric \u0111\u1eadm \u0111\u1eb7c l\u00e0m ch\u1ea5t h\u00fat \u1ea9m.<\/p>\n\n\n\n
Do v\u00f4i s\u1ed1ng v\u00e0 axit sunfuric \u0111\u1eb7c c\u00f3 t\u00e1c d\u1ee5ng \u0103n m\u00f2n r\u1ea5t m\u1ea1nh n\u00ean ph\u1ea1m vi s\u1eed d\u1ee5ng ch\u00fang l\u00e0m ch\u1ea5t h\u00fat \u1ea9m b\u1ecb h\u1ea1n ch\u1ebf. V\u00ed d\u1ee5 khi c\u1ea7n b\u1ea3o qu\u1ea3n m\u1ed9t m\u00e1y chi\u1ebfu phim, ng\u01b0\u1eddi ta kh\u00f4ng th\u1ec3 d\u00f9ng v\u00f4i s\u1ed1ng ho\u1eb7c axit sunfuric \u0111\u1ec3 l\u00e0m ch\u1ea5t h\u00fat \u1ea9m. B\u1edfi v\u00ec ch\u1ec9 c\u1ea7n s\u01a1 su\u1ea5t m\u1ed9t ch\u00fat l\u00e0 m\u00e1y chi\u1ebfu phim c\u00f3 th\u1ec3 b\u1ecb axit sunfuric v\u00e0 v\u00f4i s\u1ed1ng \u0103n m\u00f2n v\u00e0 s\u1ebd b\u1ecb h\u01b0 h\u1ecfng. V\u00ec v\u1eady c\u1ea7n t\u00ecm m\u1ed9t ch\u1ea5t h\u00fat \u1ea9m v\u1eeba kh\u00f4ng c\u00f3 t\u00ednh \u0103n m\u00f2n, v\u1eeba kh\u00f4ng \u0111\u1ed9c, l\u00e0 nh\u1eefng ch\u1ea5t \u1edf th\u1ec3 r\u1eafn c\u00f3 t\u00ednh h\u00fat n\u01b0\u1edbc m\u1ea1nh.<\/p>\n\n\n\n
N\u1ebfu c\u00f3 l\u00fac n\u00e0o \u0111\u00f3, b\u1ea1n m\u1edf bao b\u00ec c\u1ee7a m\u1ed9t m\u00e1y chi\u1ebfu phim, ho\u1eb7c t\u00fai \u0111\u1ef1ng d\u01b0\u1ee3c ph\u1ea9m, m\u00e1y m\u00f3c qu\u00fd, b\u1ea1n s\u1ebd th\u1ea5y b\u00ean trong c\u00f3 nh\u1eefng t\u00fai nh\u1ecf b\u1eb1ng v\u1ea3i ho\u1eb7c b\u1eb1ng gi\u1ea5y ch\u1ee9a \u0111\u1ea7y c\u00e1c h\u1ea1t ch\u1ea5t h\u00fat \u1ea9m: \u0111\u00f3 l\u00e0 c\u00e1c h\u1ea1t silicagel.<\/p>\n\n\n\n
Ng\u01b0\u1eddi ta cho th\u1ee7y tinh l\u1ecfng (c\u00f3 th\u00e0nh ph\u1ea7n ho\u00e1 h\u1ecdc l\u00e0 natri silicat<\/p>\n\n\n\n
Na2SiO3) t\u00e1c d\u1ee5ng v\u1edbi axit s\u1ebd t\u1ea1o th\u00e0nh axit silicxic (H2SiO3), cho s\u1ea5y kh\u00f4 \u0111\u1ec3 \u0111u\u1ed5i n\u01b0\u1edbc ta s\u1ebd nh\u1eadn \u0111\u01b0\u1ee3c c\u00e1c h\u1ea1t r\u1eafn \u0111\u1ee5c \u0111\u00f3 l\u00e0 silicagel. C\u00e1c h\u1ea1t silicagel th\u01b0\u1eddng c\u00f3 k\u00edch th\u01b0\u1edbc c\u1ee1 h\u1ea1t \u0111\u1eadu t\u01b0\u01a1ng. \u0110\u00e2y l\u00e0 nh\u1eefng h\u1ea1t r\u1eafn c\u00f3 nhi\u1ec1u l\u1ed7 nh\u1ecf, di\u1ec7n t\u00edch b\u1ec1 m\u1eb7t chung c\u1ee7a c\u00e1c l\u1ed7 nh\u1ecf kh\u00e1 l\u1edbn n\u00ean c\u00f3 t\u00e1c d\u1ee5ng h\u00fat n\u01b0\u1edbc m\u1ea1nh. Silicagel c\u00f3 kh\u1ea3 n\u0103ng h\u00fat l\u01b0\u1ee3ng n\u01b0\u1edbc \u0111\u1ebfn g\u1ea7n 40% kh\u1ed1i l\u01b0\u1ee3ng chung. D\u00f9ng silicagel l\u00e0m ch\u1ea5t h\u00fat \u1ea9m c\u00f3 nhi\u1ec1u \u01b0u \u0111i\u1ec3m: kh\u00f4ng m\u00f9i v\u1ecb, kh\u00f4ng \u0111\u1ed9c, kh\u00f4ng c\u00f3 t\u00e1c d\u1ee5ng \u0103n m\u00f2n. M\u1ed9t \u0111\u1eb7c \u0111i\u1ec3m qu\u00fd gi\u00e1 n\u1eefa c\u1ee7a silicagel l\u00e0 sau khi \u0111\u00e3 h\u1ea5p ph\u1ee5 no n\u01b0\u1edbc ch\u1ec9 c\u1ea7n \u0111em s\u1ea5y \u1edf 120\u00b0C ho\u1eb7c \u0111em ph\u01a1i n\u1eafng l\u00e0 c\u00f3 th\u1ec3 l\u1ea1i s\u1eed d\u1ee5ng \u0111\u1ec3 l\u00e0m ch\u1ea5t h\u00fat \u1ea9m. Trong qu\u00e1 tr\u00ecnh ch\u1ebf t\u1ea1o silicagel n\u1ebfu \u0111em ng\u00e2m c\u00e1c h\u1ea1t silicagel v\u00e0o dung d\u1ecbch mu\u1ed1i coban clorua, ta c\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c c\u00e1c h\u1ea1t silicagel c\u00f3 m\u00e0u. Khi h\u1ea1t silicagel c\u00f3 m\u00e0u xanh l\u00e0 c\u00e1c h\u1ea1t silicagel ch\u01b0a h\u00fat n\u01b0\u1edbc, c\u00f3 th\u1ec3 d\u00f9ng ch\u00fang l\u00e0m ch\u1ea5t h\u00fat \u1ea9m. Khi h\u1ea1t silicagel h\u00fat n\u01b0\u1edbc \u0111\u1ebfn m\u1ee9c \u0111\u1ed9 n\u00e0o \u0111\u00f3 th\u00ec ch\u00fang s\u1ebd bi\u1ebfn th\u00e0nh m\u00e0u \u0111\u1ecf, b\u00e1o hi\u1ec7u silicagel \u0111\u00e3 h\u00fat nhi\u1ec1u n\u01b0\u1edbc c\u1ea7n ph\u1ea3i \u0111em s\u1ea5y, ph\u01a1i kh\u00f4 c\u00e1c h\u1ea1t l\u1ea1i c\u00f3 m\u00e0u xanh th\u00ec m\u1edbi c\u00f3 th\u1ec3 d\u00f9ng l\u00e0m ch\u1ea5t h\u00fat \u1ea9m \u0111\u01b0\u1ee3c. Nguy\u00ean do l\u00e0 khi coban clorua \u1edf tr\u1ea1ng th\u00e1i kh\u00f4ng n\u01b0\u1edbc (tr\u1ea1ng th\u00e1i khan) s\u1ebd c\u00f3 m\u00e0u xanh. Sau khi h\u1ea5p th\u1ee5 n\u01b0\u1edbc, coban clorua s\u1ebd tr\u1edf th\u00e0nh tr\u1ea1ng th\u00e1i k\u1ebft tinh v\u1edbi c\u00e1c ph\u00e2n t\u1eed n\u01b0\u1edbc c\u00f3 m\u00e0u \u0111\u1ecf. Sau khi s\u1ea5y \u1edf nhi\u1ec7t \u0111\u1ed9 cao, n\u01b0\u1edbc k\u1ebft tinh trong tinh th\u1ec3 coban clorua s\u1ebd b\u1ecb bay h\u01a1i h\u1ebft v\u00e0 tr\u1edf l\u1ea1i coban clorua khan v\u00e0 l\u1ea1i c\u00f3 m\u00e0u xanh. Nh\u01b0 v\u1eady nh\u00ecn v\u00e0o m\u00e0u c\u1ee7a silicagel m\u00e0 ng\u01b0\u1eddi ta bi\u1ebft li\u1ec7u c\u00f3 th\u1ec3 d\u00f9ng silicagel l\u00e0m ch\u1ea5t h\u00fat \u1ea9m \u0111\u01b0\u1ee3c kh\u00f4ng. \u0110i\u1ec1u \u0111\u00f3 qu\u1ea3 l\u00e0 ti\u1ec7n l\u1ee3i.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: Ch\u1ea5t h\u00fat \u1ea9m; Silicagel.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
\u0110\u1ec3 gi\u1eef cho kh\u00f4ng kh\u00ed kh\u00f4 r\u00e1o ng\u01b0\u1eddi ta d\u00f9ng nh\u1eefng bi\u1ec7n ph\u00e1p trong \u0111\u00f3 c\u00f3 bi\u1ec7n ph\u00e1p d\u00f9ng ch\u1ea5t h\u00fat \u1ea9m. Ch\u1ea5t h\u00fat \u1ea9m l\u00e0 nh\u1eefng ch\u1ea5t c\u00f3 kh\u1ea3 n\u0103ng h\u1ea5p th\u1ee5 m\u1ea1nh h\u01a1i n\u01b0\u1edbc trong kh\u00f4ng kh\u00ed. Ng\u01b0\u1eddi Trung Qu\u1ed1c th\u1eddi c\u1ed5 \u0111\u1ea1i bi\u1ebft c\u00e1ch d\u00f9ng v\u00f4i s\u1ed1ng \u0111\u1ec3 b\u1ea3o qu\u1ea3n d\u01b0\u1ee3c li\u1ec7u, […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[8,15],"tags":[],"class_list":["post-7797","post","type-post","status-publish","format-standard","hentry","category-hoa-hoc","category-hoi-dap-khoa-hoc"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7797","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=7797"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7797\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7797"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7797"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7797"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}