1.Dễ
Trong dung dịch muối, muối được gọi là gì?
- AChất tan
- BChất xúc tác
- CDung môi
- DKết tủa
2.Dễ
What is the formula of sulfuric acid?
- AH₂SO₃
- BH₂SO₄
- CHCl
- DHNO₃
3.Dễ
What does the octet rule state?
- AAn atom can form a maximum of 8 covalent bonds
- BEvery stable atom has exactly 8 protons in its nucleus
- CAtoms tend to gain, lose or share electrons to get 8 outer electrons
- DEvery stable molecule contains exactly 8 atoms
4.Trung bình
Which statement describes a saturated fat?
- AIt contains no carbon atoms
- BIt is always liquid at room temperature
- CIts fatty acid chains have no carbon–carbon double bonds
- DIts fatty acid chains have many carbon–carbon double bonds
5.Trung bình
How is 0,00045 written in scientific notation?
- A4,5 × 10⁻⁴
- B4,5 × 10⁴
- C4,5 × 10⁻³
- D4,5 × 10⁻⁵
6.Trung bình
Hòa tan 2 mol glucose trong nước để được 4 lít dung dịch. Nồng độ mol là bao nhiêu?
- A2 M
- B4 M
- C8 M
- D0,5 M
7.Khó
Starch and cellulose are both made entirely of glucose units, yet humans can digest starch but not cellulose. Why?
- AThe glucose units are linked differently, and humans lack an enzyme to break cellulose's links
- BStarch contains nitrogen, which makes it easier to digest
- CCellulose dissolves in water, so it is lost from the gut
- DCellulose is really made of amino acids, not glucose, so stomach acid cannot break it
8.Khó
Trong 2H₂ + O₂ → 2H₂O, 4 g hydrogen (khối lượng mol 2 g/mol) phản ứng với lượng oxygen dư thừa. Khối lượng nước tạo thành là bao nhiêu (khối lượng mol 18 g/mol)?
- A18 g
- B72 g
- C4 g
- D36 g
Đáp án
- 1. A · Chất tan
- 2. B · H₂SO₄
- 3. C · Atoms tend to gain, lose or share electrons to get 8 outer electrons
- 4. C · Its fatty acid chains have no carbon–carbon double bonds
- 5. A · 4,5 × 10⁻⁴
- 6. D · 0,5 M
- 7. A · The glucose units are linked differently, and humans lack an enzyme to break cellulose's links
- 8. D · 36 g
Lời giải đầy đủ từng bước: hãy luyện chủ đề này trên examproblems.com.