giúp mk vs ạ
Giúp mk vs ạ😢😢
giúp mk vs ạ 😢
A song was sung by her.
Was the letter sent by him?
The bus was stopped.
My car was stolen by a thief.
He was not let go.
The prize wasn't won by her.
Their beds weren't made.
They were not told by me.
Were they told by you?
I was hit by him.
The letter was lost by my mother yesterday.
They key was found by her at home.
Mistakes were made.
That woman was loved by Peter 3 years ago.
The rooms were cleaned.
giúp mk vs ạ 😢
Câu 1 :
Gọi $m_{dd} = a(gam)$
$n_{NaOH} = \dfrac{a.20\%}{40} = 0,005a(mol)$
$n_{Ba(OH)_2} = \dfrac{a.8,55\%}{171} = 0,0005a(mol)$
$n_{HNO_3} = \dfrac{224}{1,1.1000}.4,5 = 0,9(mol)$
$NaOH + HNO_3 \to NaNO_3 + H_2O$
$Ba(OH)_2 + 2HNO_3 \to Ba(NO_3)_2 + 2H_2O$
Theo PTHH :
$0,005a + 0,0005a.2 = 0,9 \Rightarrow a = 150(gam)$
Câu 2 :
Gọi thể tích dung dịch cần tìm là V(lít)
$n_{H_2SO_4} = 1,1V(mol) ; n_{HCl} = 1,98V(mol)$
$\Rightarrow n_H = 1,1V.2 + 1,98V = 4,18V(mol)$
$n_{NaOH} = 0,19.3 = 0,57(mol) ; n_{Ba(OH)_2} = 0,19.4 = 0,76(mol)$
$\Rightarrow n_{OH} = 0,57 + 0,76.2 = 2,09(mol)$
$H + OH \to H_2O$
$\Rightarrow 4,18V = 2,09 \Rightarrow V = 0,5(lít)$
Câu 3 :
$n_{ZnO} = \dfrac{48,6}{81} = 0,6(mol) ; n_{HNO_3} = \dfrac{800.6,3\%}{63}= 0,8(mol)$
ZnO + 2HNO3 → Zn(NO3)2 + H2O
0,4.......0,8...............0,4........................(mol)
Sau phản ứng :
$m_{dd} = 0,4.81 +800 = 832,4(gam)$
$C\%_{Zn(NO_3)_2} = \dfrac{0,4.189}{832,4}.100\% = 9,1\%$
Mn giúp em vs ạ😢
1 A
2 C
3 C
4 D
5 B
6 A
7 B
8 D
9 C
10 C
11 B
12 D
13 B
14 C
15 B
Giúp e vs ạ😢🐰
a,NTK của Y là:1,5.16=24 (g/mol)
NTK của X là: \(\dfrac{1}{2}.24=12\left(g/mol\right)\)
b,KHHH của X là C
của Y là Mg
của Z là O
Mn giúp em vs ạ 😢
Giúp mik vs ạ🥺😢🤧
1. She usually wears a red uniform.
2. There was a concert yesterday.
1. She usually wears a red uniform
2. There was a concert yesterday
1. She usually wears a red uniform.
2. There was a concert yesterday.
Giúp mik vs ạ🤧🥺😢
We went to the dinosaur museum
A farmer found Son Doong Cave in 1991
This is hers jacket
1. We went to the dinosaur museum
2.A farmer found Son Doong Cave in 1991
3.This jacket is hers
3. We went to the dinasour museum.
4. A farmer found Son Dong Cave in 1991.
5. This jacket is hers.
Cân bằng PTHH giúp mình vs ạ😢
8. Cu(OH)2+H2SO4=>CuSO4+2H2O
9, FeO+2HCl2=>FeCl2+H2O
10, Fe2O3+3H2SO4=>Fe2(SO4)3+3H2O
11, Cu(NO3)2+2NaOH=>Cu(OH)2+2NaNO3
Giúp vs, cần gấp lắm rùi ạ😢