ncucmonster

2 năm trước

Cho 400ml dung dịch Na2CO3 0,75M tác dụng vừa đủ với 150gam dung dịch axit HCl. Dẫn toàn bộ chất khí thu được sau phản ứng vào bình đựng dung dịch Ca(OH)2 dư người ta thu được một chất kết tủa. a) Viết phương trình hóa học. b) Tính nồng độ phần trăm của dung dịch axit HCl đã dùng. c)Tìm khối lượng chất kết tủa thu được. Bài

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Trang Luong Nguyen

2 năm trước

Đáp án:

C%HCl=14,6%

mCaCO3= 30g

Giải thích các bước giải:

PTHH:

Na2CO3+ 2HCl→ 2NaCl+ CO2+H2O

CO2+ Ca(OH)2→ CaCO3+ H2O

nNa2CO3=0,4. 0,75= 0,3 mol

C%HCl=$\frac{0,3.2.36,5}{150}$ .100%=14,6 %

nCaCO3= nCO2= 0,3 mol

⇒ mCaCO3= 0,3.100= 30 g

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