mCaCO3 = 1,5 × 96,5% = 1,4475 tấn CaCO3 → CaO + CO2 100 → 56 mCaO lý thuyết = 1,4475 × 56 / 100 = 0,8106 tấn m thực tế = 0,8106 × 85% ≈ 0,689 tấn

Hiện tượng: Na phản ứng với nước, tạo khí H2, dung dịch có kết tủa xanh lam Cu(OH)2.

PTHH:

2Na + 2H2O → 2NaOH + H2

CuSO4 + 2NaOH → Cu(OH)2↓ + Na2SO4

Mạng tinh thể kim loại: các ion dương nằm ở nút mạng, xung quanh là electron tự do.

Liên kết kim loại: lực hút giữa ion dương kim loại và electron tự do.

Bài 3: m chất tan = 91,8 g m dung dịch = 91,8 + 100 = 191,8 g C% = (91,8 / 191,8) × 100% ≈ 47,9%

2: (1) Mg + 2HCl → MgCl2 + H2 (2) MgCl2 + 2NaOH → Mg(OH)2 + 2NaCl (3) Mg(OH)2 → MgO + H2O (4) MgO + H2SO4 → MgSO4 + H2O

Nhiệt luyện: Fe2O3 + 3CO → 2Fe + 3CO2 Điện phân: 2NaCl → 2Na + Cl2 Thủy luyện: CuSO4 + Fe → FeSO4 + Cu

In recent years, the increasing celebration of festivals such as Christmas and Halloween among young Vietnamese people has sparked a debate on cultural influence. While some view this trend as harmless, others express concern about the potential erosion of traditional values. 

In my opinion, celebrating these festivals can be beneficial for several reasons. Firstly, it promotes cultural exchange and broadens horizons. Embracing different traditions allows young people to become more open-minded and globally aware. This can foster a more inclusive society where diversity is appreciated rather than feared. 

Secondly, these celebrations provide opportunities for socializing and community building. Festivals like Christmas and Halloween bring people together, creating joyful and memorable experiences. They offer a break from routine and can enhance the sense of belonging among young people, especially in urban areas where traditional community ties might be weaker.

However, it is crucial to balance this with the preservation of Vietnamese traditions. Promoting traditional festivals and cultural education can ensure that young people remain connected to their roots while enjoying the benefits of global cultural exposure. In conclusion, the celebration of foreign festivals should be seen as an enriching addition to, rather than a replacement for, Vietnamese culture.