a)
K + H2O → KOH + 1/2H2↑ (1)
BaO + H2O → Ba(OH)2 (2)
nH2 = 4,48 : 22,4 = 0,2 mol
Theo (1) => nK = 0,2.2 = 0,4 mol <=> mK = 0,4.39 = 15,6 gam
=> %mK = \(\dfrac{15,6}{29,3}\).100% = 53,24% <=> %mBaO = 100 - 53,24 = 46,76 %
b)
mBaO = 29,3 - 15,6 = 13,7 gam <=> nBaO = \(\dfrac{13,7}{153}\) mol
Từ (1) , (2) => mBazơ = mKOH + mBa(OH)2
<=> mBazơ = 0,4. 56 + \(\dfrac{13,7}{153}\).171 = 37,7 gam
hon hop 3 kim loai gom Fe,Al,Cu nang 17,4 g hoa tan bang 100g dung dich H2SO4 39,2% du thi thoat ra V lit khi H2 o dktc va 1 g chat ran khong tan . Tinh V va khoi luong moi kim loai ban dau
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
Tinh khoi luong cua hon hop gom
a. 0.5 mol O2 va 1.5 phan tu CO2
b.4.48 lit khi cacbonic va 33.6 lit khi hidro (cac the tich khi do o dieu kien tieu chuan)
dung khi H2 khu 31,2 gam hon hop CuO va Fe3O4 ta thu duoc 23,2 gam hon hop 2 kim loai .Thanh phan %cua 2 chat trong hon hop ban dau la
A, 30%CuO,70%FeO B, 40%CuOva 60%fe3O4
C, 20%CuoO va 80 %Fe3O4 D. 25,64%CuO va 74,36%Fe3O4
cho 24 g Mg tac dung vua du voi dd HCl co nong do 7,3%. Sau khi phan ung xay ra hoan toan, hay tinh
a, The tich khi thoat ra (DKTC)
b,Tinh khoi luong dd HCl da phan ung
cho 6,5g ke tac dung voi 7,3g axit clohdric . phan ung ket thuc thu dc muoi kem clorua va khi hidro theo ti le khoi luong la 68:1 . khoi luong cua muoi kem clorua va khi hidro lan luot la :
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 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
mot hop chat gom 2 nguyen tu nguyen to X lien ket voi 5 nguyen tu O va nang hon phan tu hidro 71 lan.
-tinh phan tu hoi cua hop chat
-tinh nguyen tu X, cho biet ten va ki hieu cua nguyen to
