a. PTHH: CuO + H₂SO₄ ---> CuSO₄ + H₂O

b. Ta có: \(n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right)\)

Theo PT: \(n_{H_2SO_4}=n_{CuO}=0,1\left(mol\right)\)

=> \(m_{H_2SO_4}=0,1.98=9,8\left(g\right)\)

Ta có: \(C_{\%_{H_2SO_4}}=\dfrac{9,8}{m_{dd_{H_2SO_4}}}.100\%=4,9\%\)

=> \(m_{dd_{H_2SO_4}}=200\left(g\right)\)

c. Ta có: \(m_{dd_{CuSO_4}}=200+8=208\left(g\right)\)

Theo PT: \(n_{CuSO_4}=n_{CuO}=0,1\left(mol\right)\)

=> \(m_{CuSO_4}=0,1.160=16\left(g\right)\)

=> \(C_{\%_{CuSO_4}}=\dfrac{16}{208}.100\%=7,69\%\)

Ta có: \(\sqrt{\dfrac{1}{x^2}+\dfrac{1}{y^2}+\dfrac{1}{z^2}}\)

\(=\sqrt{\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)^2-2\cdot\left(\dfrac{1}{xy}+\dfrac{1}{yz}+\dfrac{1}{xz}\right)}\)

\(=\sqrt{\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)^2-2\cdot\dfrac{x+y+z}{xyz}}\)

\(=\sqrt{\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)^2}\)

\(=\left|\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right|\)

1 Who have the custom of making....?

2 What do people in the Central Highlands believe?

3 What would they do if the dead weren't buried in beautiful graves

4 What do they make funeral houses and cutting wooden statues for?

5 How many tools do people in the central highlands use to make statues

6 What are the topics for funeral statues aken from?

a) \(n_{CO_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

PTHH: CO₂ + CaO → CaCO₃

Mol:      0,1                      0,1

b) \(m_{CaCO_3}=0,1.100=10\left(g\right)\)

a sai vì 4 ko phải số nguyên tố

b sai lun vì 2x3 =6 trong đó 2 và 3 đều là số nguyên tố mà tích là 6 là số chẵn

13.A

14.B

15.A

13, A
14, C
15, A

13. A

14. B

15. A

2. D

3. A