\(n_{Na} = \dfrac{23}{23} = 1(mol)\\ 2Na + 2H_2O \to 2NaOH + H_2\\ n_{H_2} = \dfrac{1}{2}n_{Na} = 0,5(mol)\\ m_{dd\ sau\ pư} = m_{Na} + m_{H_2O} - m_{H_2} = 23 + 228 - 0,5.2 = 250(gam)\\ n_{NaOH} = n_{Na} = 1(mol)\\ V_{dd\ sau\ pư} = \dfrac{250}{1,05} = 238(ml)\)
Suy ra :
\(C\%_{NaOH} =\dfrac{1.40}{250}.100\% = 16\%\\ C_{M_{NaOH}} = \dfrac{1}{0,238} = 4,2M\)
Tron 250 ml dung dich hon hop gom HCL 0.08M va H2SO4 0.01M voi 250 ml dung dich Ba(OH)2 a mol l, thu duoc m gam ket tua va dung dich sau phan ung co the tich 500 ml va co pH=12. Tinh m va a
hoa tan 93gam NaOH 20%vao 527 ml H2O (D H2O=1g/ml).tinh nong do %cua dung dich thu duoc
tron 120 gam dung dich NaOH 20%voi 180 gam dung dich NaOH 15%. Dung dich duoc sau khi tron co C%la bao nhieu
co 1,6 mol NaCl tan trong nuoc tao thanh 800ml dung dich , phai them bao nhieu ml nuoc vao dung dich do de duoc dung dich NaCl co nong do 1,6M
hoa tan x gam Fe tan vua het 200 gam dung dich HCL .14,6 %. Hay tinh
a, Gia tri cua x
b, the tich khi H2 thoat ra o dktc
c, C%cua dung dich thu duoc sau phan ung
o nhiet do phong thi nhiem (20do C), 10 gam nuoc hoa tan toi da duoc 3,6gam muoi an . Vay de co 200 gam dung dich muoi an bao hoa can luong muoi an va nuoc la bao nhieu
hoa tan hoan toan 8,4 gam kim loai X trong dung dich HCL 20%thu duoc 3,36lit H2(o dktc). Xac dinh kim loai X va khoi luong dung dich axit can dung
them 15.3g BaO vao 134.7g nuoc duoc dung dich X.Tinh C% chat tan trong dung dich
cho 6 5 gam kem tac dung vua du voi dung dich hydrochloric acid HCL thi thu duoc dung dich zinc chloride ZnCl2 va khi hydrogen thoat ra A viet PTHH B tinh khoi luong hydrochloric acid HCL tham gia phan ung C tinh khoi luong zinc chloride ZnCl2 tao thanh D tinh the tich khi hydrogen thoat ra o dieu kien chuan 25 do C 1 bar
Cho Zn=65 H=1 Cl= 35.5
