1. Combustion of ethanol takes place according to the following unbalanced equation.

___ C2H5OH (l) + ___ O2 (g) → ___ CO2 (g) + ___ H2O (l)

What is the mole ratio of ethanol to oxygen in the balanced equation?

A. 1:1

B. 2:1

C. 1:3

D. 2:7

2. Which sample contains the largest amount, in mol, of oxygen atoms?

A. 0.20 mol P2O5

B. 0.30 mol O3

C. 0.40 mol CH3COOH

D. 0.80 mol H2O

3. Which compound has the highest percentage of carbon by mass?

A. CH4

B. C2H4

C. C4H10

D. C6H6

4. Which solution contains the biggest amount, in mol, of chloride ions?

A. 20 cm3 of 0.50 mol dm−3 NH4Cl

B. 60 cm3 of 0.20 mol dm−3 MgCl2

C. 70 cm3 of 0.30 mol dm−3 NaCl

D. 100 cm3 of 0.30 mol dm−3 ClCH2COOH

5. Which statement about the isotopes of nitrogen is correct?

6. Ultraviolet radiation has a shorter wavelength than infrared radiation. How does the frequency and energy of ultraviolet radiation compare with infrared radiation?

7. What is the total number of valence electrons in CH3COO?

A. 16

B. 22

C. 23

D. 24

8. What is the definition of the term first ionization energy?

A. The energy released when one mole of electrons is removed from one mole of gaseous atoms.

B. The energy required to remove one mole of electrons from one mole of gaseous atoms.

C. The energy released when one mole of gaseous atoms gains one mole of electrons.

D. The energy required to add one mole of electrons to one mole of gaseous atoms

9. What describes the structure of silicon and silicon dioxide?

10. Which molecules react to form a dative covalent (coordinate) bond?

A. CH4 and NH3

B. C2H2 and Cl2

C. NH3 and HF

D. Cl2 and HF




您的电子邮箱地址不会被公开。 必填项已用*标注