1) a) Hoa tan 12,5 gam tinh the CuSO4. 5H2O trong nuoc thanh 200ml dd. Tinh nong do mol cac ion trong dd thu duoc
b) Hoa tan 8,08 gam Fe(NO3)3.9H2O trong nuoc thanh 500 ml dd. Tinh nong do mol cac ion trong dd thu duoc
DE CUONG ON TAP HK1 MON HOA HOC
1. hoa tan 0,54 gam nhom vao dd 120 gam dd h2so4 4,9% thoat ra V lit khi hidro (dktc)
a) viet pthh . tinh V ?
b) tinh nong do phan tram cua cac chat trong dd sau phan ung ?
2. hoa tan 15,5 gam na2o vao nuoc thanh 500 ml dung dich A
a) viet pthh xay ra
b) tinh nong do mol cua dd A
c) tinh the tich dd h2so4 20% ( D = 1,14g/ml ) can de trung hoa luong dd tren
1.
Theo đề bài ta có : \(\left\{{}\begin{matrix}nAl=\dfrac{0,54}{27}=0,02\left(mol\right)\\nH2SO4=\dfrac{120.4,9}{100.98}=0,06\left(mol\right)\end{matrix}\right.\)
PTHH :
\(2Al+3H2SO4->Al2\left(So4\right)3+3H2\uparrow\)
0,02mol...0,03mol.......0,01mol.............0,03mol
Theo PTHH ta có : nAl = \(\dfrac{0,02}{2}mol< nH2SO4=\dfrac{0,06}{2}mol=>nH2SO4\left(dư\right)\) ( tính theo nal)
=> VH2(đktc) = 0,03.22,4 = 6,72(l)
=> \(\left\{{}\begin{matrix}C\%ddH2SO4\left(dư\right)=\dfrac{\left(0,06-0,03\right).98}{0,54+120-0,03.2}.100\%\approx2,44\%\\C\%ddAl2\left(SO4\right)3=\dfrac{0,01.302}{0,54+120-0,03.2}.100\%\approx2,5\%\end{matrix}\right.\)
Theo đề bài ta có : nNa2O = \(\dfrac{15,5}{62}=0,25\left(mol\right)\)
a) PTHH :
\(Na2O+H2O->2NaOH\)
0,25mol....0,25mol.....0,5mol
b) Nồng độ mol dd A là :
CMddNaOH = 0,5/0,5 = 1(M)
c) PTHH :
\(2NaOH+H2SO4->Na2SO4+H2O\)
0,5mol.........0,25mol
=> mddH2SO4 = \(\dfrac{0,25.98}{20}.100=122,5\left(g\right)=>VddH2SO4=\dfrac{122,5}{1,14}\approx107,5\left(ml\right)\)
1) Hoa tan 20g NaOH vao 500ml nuoc thu duoc dung dich A
a) Tinh nong do cac ion trong dd A
b) Tinh the tich dung dich HCl 2M de trung hoa dd A
\(a.n_{NaOH}=\dfrac{20}{40}=0,5\left(mol\right)\\ \left[Na^+\right]=\left[OH^-\right]=\left[NaOH\right]=\dfrac{0,5}{0,5}=1\left(M\right)\\ b.HCl+NaOH\rightarrow NaCl+H_2O\\ n_{HCl}=n_{NaOH}=0,5\left(mol\right)\\ V_{ddHCl}=\dfrac{0,5}{2}=0,25\left(l\right)\)
1) Tron 150 ml dd NaOH 1M voi 100 ml dd KOH 0,5M thu duoc dung dich C
a) Tinh nong do cac ion trong dd C
b) Trung hoa dd C bang 200 ml dd H2SO4 co nong do mol la a mol/ lit. Tinh a
\(a.n_{NaOH}=1.0,15=0,15\left(mol\right)\\ n_{KOH}=0,5.0,1=0,05\left(mol\right)\\ \left[Na^+\right]=\left[NaOH\right]=\dfrac{0,15}{0,15+0,1}=0,6\left(M\right)\\ \left[K^+\right]=\left[KOH\right]=\dfrac{0,05}{0,1+0,15}=0,2\left(M\right)\\ \left[OH^-\right]=0,2+0,6=0,8\left(M\right)\\ b.2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\\ 2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\\ n_{H_2SO_4}=\dfrac{1}{2}.\left(n_{KOH}+n_{NaOH}\right)=\dfrac{0,15+0,05}{2}=0,1\left(mol\right)\\ a=C_{MddH_2SO_4}=\dfrac{0,1}{0,2}=0,5\left(M\right)\)
Trung hoa hoan toan v ml dd HNO3 1M can dung vua du 200ml dd NAOH 0,5M thu duoc dd X. Xac dinh gia tri cua V va tinh nong do mol cua cac ion trong dung dich X
\(n_{H^+}=n_{HNO_3}=V\)mol
\(n_{OH^-}=n_{NaOH}=0,5.0,2=0,1\) mol
\(H^++OH^-\rightarrow H_2O\)
0,1<--0,1
\(\Rightarrow n_{H^+}=V=0,1\)lít = 100 ml
\(NaOH+HNO_3\rightarrow NaNO_3+H_2O\)
0,1 -----> 0,1 ---------->0,1
\(NaNO_3\rightarrow Na^++NO_3^-\)
\(\Rightarrow\left[Na^+\right]=\left[NO_3^-\right]=\dfrac{0,1}{0,1+0,2}=0,33M\)
hoa tan 7,8g kali vao nuoc thu200ml dd A a) viet phuong trinh va tinh the tich khi thoat ra b) tinh nong do mol chat tan co trong dd A c) dan 8,96l CO2 vao dd A tinh khoi luong chat tan thu duoc
Hoà tan 4 gam Cuso4 vào một luong nuoc vua du duoc 250ml dung dich.
a) tinh nong do mol cua cac ion trong dung dich tren.
b) tinh the tich dung dich NaOH 0,25M du de lam ket tua het cation trong dung dich tren
1) Tron 100 ml dd HCl 1M voi 100 ml dd H2SO4 0,5M thu duoc dd D
a) Tinh nong do cac ion trong dd D
b) Cho dd D tac dung voi dd BaCl2 du thu duoc m gam ket tua. Tinh m
\(a.n_{HCl}=0,1.1=0,1\left(mol\right)\\ n_{H_2SO_4}=0,5.0,1=0,05\left(mol\right)\\ \left[HCl\right]=\dfrac{0,1}{0,1+0,1}=0,5\left(M\right)\\ \left[H_2SO_4\right]=\dfrac{0,05}{0,1+0,1}=0,25\left(M\right)\\ \left[H^+\right]=0,5+0,25.2=1\left(M\right)\\ \left[SO^{2-}_4\right]=\left[H_2SO_4\right]=0,25\left(M\right)\\ \left[Cl^-\right]=\left[HCl\right]=0,5\left(M\right)\)
\(b.BaCl_2+H_2SO_4\rightarrow BaSO_4\downarrow+2HCl\\ n_{BaSO_4}=n_{H_2SO_4}=0,05\left(mol\right)\\ m_{\downarrow}=m_{BaSO_4}=233.0,05=11,65\left(g\right)\)
Cau 1: hoa tan 4g NaOH vao 200ml nuoc. Tinh nong do mol/l cua dd thu duoc. Tinh nong do % cua dd thu dc. Tinh do pH cua dd thu dc. Cho 100ml dd thu dc o tren tac dung voi 100ml dd CuSO4 1M. Tinh k.luong ket tua thu dc
Cau2: dot chay 600g 1 mau than da chua tap chat khong chay thu dc 1met khoi khi CO2(dktc). Tinh % ve k.luong cacbon trong than
Cau3: de dieu che 500g TNT can dung bao nhieu gam toluen biet hieu suat phan ung la 90%
Cau4: cho 6g axit axetit tac dung 1 luong du ancol etilit co H2SO4 dac lm xuc tac. Tinh k.luong este thu dc biet hieu suat la 65%
Tron 200ml dung dich Ba(OH)2 0,05M voi 300ml dung dich HCl co pH=1, sau phan ung thu duoc A:
a. Tinh nong do mol/l cac ion trong dd A? tinh pH dd A?
b. them 250ml dd gom H2SO4 0,1M va Na2SO4 0,1M vao dd A sau phan ung thu duoc dd B va ket tua C . Tinh khoi luong ket tua va so mol cac ion trong dd B?
\(a)n_{Ba\left(OH\right)_2}=0,05\cdot0,2\cdot2=0,02mol\\ pH=1\Rightarrow\left[OH^-\right]=0,1M\Rightarrow n_{HCl}=0,1\cdot0,3=0,03mol\\ n_{Ba\left(OH\right)_2}+n_{HCl}=0,02+0,03=0,05mol\\ \Rightarrow C_M=\dfrac{0,05}{0,5}=0,1M\Rightarrow pH=1\)