Dung dịch và nồng độ

Home Lớp 8 Khoa học tự nhiên 8 - sách Kết nối tri thức Bài 4: Dung dịch và nồng độBài tập nâng cao

{"common":{"save":0,"post_id":"8515","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7566","post_id":"8515","mon_id":"1159539","chapter_id":"1159541","question":"Tr\u1ed9n l\u1eabn 2 lít dung d\u1ecbch urea 0,02 M (dung d\u1ecbch A) v\u1edbi 3 lít dung d\u1ecbch urea 0,1 M (dung d\u1ecbch B), thu \u0111\u01b0\u1ee3c 5 lít dung d\u1ecbch C. Tính n\u1ed3ng \u0111\u1ed9 mol c\u1ee7a dung d\u1ecbch C?<\/p>","options":["A. 0,43 M","B. 0,34 M","C. 0.68 M","D. 0,86 M"],"correct":"3","level":"3","hint":"D\u1ef1a vào công th\u1ee9c tính n\u1ed3ng \u0111\u1ed9 mol c\u1ee7a dung d\u1ecbch C<\/p>","answer":"\u0110áp án \u0111úng: C. 0.68 M<\/strong><\/p>S\u1ed1 mol dung d\u1ecbch urea 0,02M = 2 . 0,02 = 0,04 mol<\/p>S\u1ed1 mol dung d\u1ecbch urea 0,1M = 3 . 0,1 = 0,3 mol<\/p>T\u1ed5ng s\u1ed1 mol dung d\u1ecbch urea sau khi tr\u1ed9n là: 0,03 + 0,04 = 0,07 mol<\/p>C$_{M}$<\/span> dung d\u1ecbch sau tr\u1ed9n: 0,07 : 5 = 0,068M<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"139","test":"0","date":"2025-02-23 23:52:01","option_type":"txt","len":0},{"id":"7567","post_id":"8515","mon_id":"1159539","chapter_id":"1159541","question":"\u1ede nhi\u1ec7t \u0111\u1ed9 25 oC, khi cho 12 gam mu\u1ed1i X vào 20 gam n\u01b0\u1edbc, khu\u1ea5y k\u0129 thì còn l\u1ea1i 5 gam mu\u1ed1i không tan. Tính \u0111\u1ed9 tan c\u1ee7a mu\u1ed1i X?<\/p>","options":["A. 35","B. 36","C. 37","D. 38"],"correct":"1","level":"3","hint":"\u0110\u1ed9 tan \u0111\u01b0\u1ee3c tính b\u1eb1ng công th\u1ee9c: S = m$_{ct}$<\/span> \/ m$_{H_{2}O}$<\/span>.100.<\/p>","answer":"\u0110áp án \u0111úng: A. 35<\/strong><\/p>Ta có: m$_{H_{2}O}$<\/span> = 20 gam; m$_{ct}$<\/span> = 12 – 5 = 7 gam.<\/p>V\u1eady S = 7 \/ 20.100 = 35 (g\/100 g n\u01b0\u1edbc).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"139","test":"0","date":"2025-02-23 23:54:45","option_type":"txt","len":0},{"id":"7568","post_id":"8515","mon_id":"1159539","chapter_id":"1159541","question":"N\u1ed3ng \u0111\u1ed9 c\u1ee7a dung d\u1ecbch t\u0103ng nhanh nh\u1ea5t khi nào?<\/p>","options":["A. T\u0103ng l\u01b0\u1ee3ng ch\u1ea5t tan \u0111\u1ed3ng th\u1eddi t\u0103ng l\u01b0\u1ee3ng dung môi","B. T\u0103ng l\u01b0\u1ee3ng ch\u1ea5t tan \u0111\u1ed3ng th\u1eddi gi\u1ea3m l\u01b0\u1ee3ng dung môi","C. T\u0103ng l\u01b0\u1ee3ng ch\u1ea5t tan \u0111\u1ed3ng th\u1eddi gi\u1eef nguyên l\u01b0\u1ee3ng dung môi","D. Gi\u1ea3m l\u01b0\u1ee3ng ch\u1ea5t tan \u0111\u1ed3ng th\u1eddi gi\u1ea3m l\u01b0\u1ee3ng dung môi"],"correct":"2","level":"3","hint":"N\u1ed3ng \u0111\u1ed9 c\u1ee7a dung d\u1ecbch là t\u1ec9 l\u1ec7 gi\u1eefa l\u01b0\u1ee3ng ch\u1ea5t tan và dung môi. Hãy suy ngh\u0129 v\u1ec1 tr\u01b0\u1eddng h\u1ee3p nào s\u1ebd làm t\u0103ng nhanh nh\u1ea5t t\u1ec9 l\u1ec7 ch\u1ea5t tan so v\u1edbi dung môi, khi c\u1ea3 hai y\u1ebfu t\u1ed1 thay \u0111\u1ed5i.<\/p>","answer":"\u0110áp án \u0111úng: B. T\u0103ng l\u01b0\u1ee3ng ch\u1ea5t tan \u0111\u1ed3ng th\u1eddi gi\u1ea3m l\u01b0\u1ee3ng dung môi<\/strong><\/p>N\u1ed3ng \u0111\u1ed9 dung d\u1ecbch t\u0103ng nhanh nh\u1ea5t khi t\u0103ng l\u01b0\u1ee3ng ch\u1ea5t tan \u0111\u1ed3ng th\u1eddi gi\u1ea3m l\u01b0\u1ee3ng dung môi<\/strong>, vì khi dung môi b\u1ecb gi\u1ea3m \u0111i, t\u1ec9 l\u1ec7 ch\u1ea5t tan so v\u1edbi dung môi s\u1ebd t\u0103ng nhanh, làm n\u1ed3ng \u0111\u1ed9 t\u0103ng m\u1ea1nh.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"139","test":"0","date":"2025-02-23 23:56:18","option_type":"txt","len":3}]}