Question

彬彬因身體不適去醫(yī)院看病，醫(yī)生在處方中給他開了三瓶生理鹽水（每瓶250mL）和相關(guān)藥劑．已知生理鹽水是溶質(zhì)質(zhì)量分?jǐn)?shù)約為0.9%、密度近似為1g/cm^-3的氯化鈉溶液，則三瓶生理鹽水中所含氯化鈉的質(zhì)量約是

1. A.
   2.25g
2. B.
   6.75g
3. C.
   7.5g
4. D.
   9g

Answer 1

B
分析：首先利用溶液的密度，計(jì)算750mL的生理鹽水的質(zhì)量；最后利用溶質(zhì)質(zhì)量=溶液質(zhì)量×溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)即可計(jì)算生理鹽水中溶質(zhì)氯化鈉的質(zhì)量．
解答：三瓶生理鹽水的質(zhì)量=250mL×3×1g/mL=750g；
則750g生理鹽水中NaCl的質(zhì)量=750g×0.9%=6.75g；
故選B．
點(diǎn)評(píng)：本題為根據(jù)溶液的溶質(zhì)質(zhì)量分?jǐn)?shù)計(jì)算的最基礎(chǔ)的計(jì)算，直接利用“溶質(zhì)質(zhì)量=溶液質(zhì)量×溶質(zhì)的質(zhì)量分?jǐn)?shù)”解決．