Kimyo-7 Savolnoma 1-chorak 1-nazorat ishi uchun Kimyo fani nimani o’rganadi? 2

KIMIYO – 7. II – chorak. 4 – nazorat ishi. 2- variant
1. SiO₂ ning tarkibida necha foiz kislorod borligini hisoblang. A) 25% B) 50% C) 53% D) 66%
2. 18 g suvning parchalanishidan hosil bo’ladigan vodorodning massasini hisoblang.
A) 2 g B) 8 g C) 16 g D) 18g
3. Tarkibi 50% S va 50% O dan iborat bo’lgan moddaning kimyoviy formulasini aniqlang.
A) SO B) SO₂ C) SO₃ D) S₂O₂
4. Ozondan kislorod hosil bo’lish reaksiyasi 3O₂ = 2O₃ – 289 kJ tarzida ifodalanadi. Shunga ko’ra 1 mol ozon hosil bo’lishi uchun qancha issiqlik yutilishini hisoblang.
A) 144,5 kJ B) 289 kJ C) 578 kJ D) 2890 kJ
5. Vazni 60 kg bo’lgan insonning tanasidagi kislorod miqdori necha kg ni tashkil etishini hisoblang.
A) 39 kg B) 52 kg C) 55 kg D) 63 kg