2019秋九年級(jí)化學(xué)下冊(cè) 第九單元 溶液 課題3 溶解的濃度 課時(shí)1 溶質(zhì)的質(zhì)量分?jǐn)?shù)(內(nèi)文)課件 新人教版.ppt
第九單元溶液,下冊(cè),課題3溶解的濃度,課時(shí)1溶質(zhì)的質(zhì)量分?jǐn)?shù),課前預(yù)習(xí),1.溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)是_,可以用_進(jìn)行計(jì)算。溶液的質(zhì)量分?jǐn)?shù)越大,說(shuō)明溶液中溶質(zhì)的相對(duì)含量越_(填“高”或“低”)。2.溶質(zhì)質(zhì)量=溶液質(zhì)量_=溶液質(zhì)量-_。3.溶液質(zhì)量=溶質(zhì)質(zhì)量+_=溶質(zhì)質(zhì)量_。,溶質(zhì)質(zhì)量與溶液質(zhì)量之比,溶質(zhì)的質(zhì)量分?jǐn)?shù)=100,高,溶質(zhì)質(zhì)量分?jǐn)?shù),溶劑質(zhì)量,溶劑質(zhì)量,溶質(zhì)質(zhì)量分?jǐn)?shù),4.實(shí)驗(yàn)說(shuō)明:溶質(zhì)的質(zhì)量分?jǐn)?shù)越大,溶液越_(填“濃”或“稀”);同種溶液,顏色越深,含溶質(zhì)質(zhì)量分?jǐn)?shù)越_,濃度越_。(后兩空填“大”或“小”)5.(1)溶液稀釋的計(jì)算原理:稀釋前_的質(zhì)量=稀釋后_的質(zhì)量;(2)溶液稀釋的計(jì)算公式:_濃溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)=稀溶液的質(zhì)量_;(3)溶液稀釋時(shí)需要加水的質(zhì)量=_的質(zhì)量_的質(zhì)量。,濃溶液,濃,大,大,溶質(zhì),溶質(zhì),濃溶液質(zhì)量,稀溶液溶質(zhì)的質(zhì)量分?jǐn)?shù),稀溶液,課堂演練,新知一溶質(zhì)的質(zhì)量分?jǐn)?shù)典例精練【例1】把20g蔗糖放到80g水中,完全溶解所得溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為()A.10%B.20%C.25%D.30%,B,【例2】下列關(guān)于“10%的硝酸鉀溶液”含義的說(shuō)法錯(cuò)誤的是()A.100g水中溶解了10g硝酸鉀B.100g硝酸鉀溶液中有10g硝酸鉀C.將10g硝酸鉀溶于90g水中所得的溶液D.將硝酸鉀與水按19的質(zhì)量比配制的溶液,A,模擬演練1.某溫度時(shí),把50gA物質(zhì)放入50g水中充分溶解后,剩余20g固體,則該溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為()50%B.20%C.37.5%D.41.5%2.某氯化鈉溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為16%,它表示()A100g水中溶解了16g氯化鈉B100mL氯化鈉溶液中氯化鈉占16gC100mL溶液中氯化鈉占16mLD100g氯化鈉溶液中含氯化鈉16g,C,D,新知二溶液的稀釋或濃縮典例精練【例3】500g90的硫酸溶液加水稀釋成30的稀溶液,稀釋后稀硫酸的質(zhì)量為()A.1000gB.1500gC.200gD.300g【例4】向50g某硫酸溶液中加入100g20%的硫酸溶液,混合液中硫酸的質(zhì)量分?jǐn)?shù)變?yōu)?0%,則原硫酸溶液中硫酸的質(zhì)量分?jǐn)?shù)為()A20%B50%C30%D40%,B,B,模擬演練3.將50g20%的硝酸鉀溶液稀釋到200g,稀釋后所得的溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)是()A.20%B.10%C.5%D.1%4.欲使50g10%的硝酸鈉溶液的質(zhì)量分?jǐn)?shù)增大一倍,可采取的方法是()A再加5g硝酸鈉B蒸發(fā)掉一半的溶劑C加入50g10%的硝酸鈉溶液D蒸發(fā)掉25g水,C,D,課后作業(yè),夯實(shí)基礎(chǔ),知識(shí)點(diǎn)1溶質(zhì)的質(zhì)量分?jǐn)?shù)1.在t時(shí),把A物質(zhì)5g放入97g水中充分?jǐn)嚢瑁玫?00g溶液。則溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)約為()A.3%B.5%C.5.15%D.49%2.現(xiàn)有溶質(zhì)質(zhì)量分?jǐn)?shù)為20%的氯化鈉溶液100g,倒出50g后,溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)為()A.10%B.20%C.30%D.40%,A,B,知識(shí)點(diǎn)2溶液的稀釋或濃縮3.80g質(zhì)量分?jǐn)?shù)為20%的濃鹽酸加水稀釋成10%的稀鹽酸,需加水的質(zhì)量為()A.80gB.100gC.280gD.200g4.有100g10%的鹽酸溶液,要使其溶質(zhì)質(zhì)量分?jǐn)?shù)增大一倍,應(yīng)采取的方法是()A.把溶液的量倒掉一半B.溶質(zhì)的質(zhì)量增大一倍C.將100g10%的鹽酸與200g25%的鹽酸混合D.蒸發(fā)掉溶劑的質(zhì)量是原溶劑質(zhì)量的一半,A,C,5.有一定質(zhì)量的質(zhì)量分?jǐn)?shù)為12%的KCl溶液,當(dāng)蒸發(fā)掉120g水后,溶質(zhì)的質(zhì)量分?jǐn)?shù)變?yōu)?4%,則原溶液中溶質(zhì)的質(zhì)量為()A.12gB.14.4gC.24gD.28.8g,D,能力提升6.向一定質(zhì)量分?jǐn)?shù)的KNO3溶液中逐漸加水稀釋?zhuān)铝袌D象中符合此溶液中溶質(zhì)質(zhì)量變化規(guī)律的是(),D,7.如圖9-3-1是甲、乙兩種固體物質(zhì)在水中的溶解度曲線。(1)t1時(shí),甲的溶解度_(填“”“”或“=”)乙的溶解度;,(2)將t2時(shí)甲、乙的飽和溶液分別升溫至t3,甲溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)將_(填“增大”“減小”或“不變”,下同),乙溶液中溶質(zhì)的質(zhì)量分?jǐn)?shù)將_;(3)t2時(shí),甲的飽和溶液中溶質(zhì)的質(zhì)量m甲與乙的飽和溶液中溶質(zhì)的質(zhì)量m乙相比較,兩者的大小關(guān)系是_(填序號(hào))。A.m甲m乙B.m甲m乙C.m甲=m乙D.不確定,D,不變,減小,8.食醋是常用的調(diào)味品。小李同學(xué)用食醋(含有4%的醋酸)配制5瓶(每瓶盛500g)含溶質(zhì)質(zhì)量分?jǐn)?shù)為2%的醋酸溶液。求:(1)配制出的5瓶醋酸溶液的總質(zhì)量;(2)配制過(guò)程中需要加蒸餾水的質(zhì)量。,解:(1)配制出的5瓶醋酸的總質(zhì)量是5500g=2500g(2)設(shè)需要加蒸餾水的質(zhì)量為x,根據(jù)溶液稀釋前后溶質(zhì)質(zhì)量不變得(2500g-x)4%=2500g2%x=1250g答:(1)配制出的5瓶醋酸溶液的總質(zhì)量是2500g;(2)配制過(guò)程中需要加蒸餾水的質(zhì)量是1250g。,