1. Which amount of the following compounds contains the least number of ions?

A. 2 mol of NaOH

B. 1 mol of NH4Cl

C. 2 mol of CaCl2

D. 1 mol of Al2O3

2. What is the approximate molar mass, in g mol–1, of MgSO· 7H2O?

A. 120

B. 130

C. 138

D. 246

3. Which is both an empirical and a molecular formula?

A. C5H12

B. C5H10

C. C4H8

D. C4H10

4. 12 molecules of hydrogen gas, H2(g), and 5 molecules of oxygen gas, O2(g), were mixed together under conditions which allowed the reaction to go to completion, according to the following equation.

2H2(g) + O2(g) → 2H2O(g) 

The following diagram represents the mixture of reactants.

Which diagram represents the reaction mixture when the reaction was complete?

5. Which of the following is an isotope of 2412 Mg ?

A. 2412 Mg2+

B. 1226 Mg

C. 1342 Mg

D. 1326 Mg

6. Which describes the visible emission spectrum of hydrogen?

A. A series of lines converging at longer wavelength

B. A series of regularly spaced lines

C. A series of lines converging at lower energy

D. A series of lines converging at higher frequency

7. Which statements about the periodic table are correct?

  • I. Elements in period 3 have similar chemical properties.
  • II. Elements in group 7 show a gradual change in physical properties.
  • III. The position of an element in period 3 is related to the number of electrons in the highest occupied energy level.

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

8. Which statements about period 3 are correct?

  • I. The electronegativity of the elements increases across period 3.
  • II. The atomic radii of the elements decreases across period 3.
  • III. The oxides of the elements change from acidic to basic across period 3.

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

9. Which is the best description of the bonding present in the ammonium ion, NH4+?

A. Sharing of electrons between atoms

B. Electrostatic attraction between ions

C. Electrostatic attraction between positive ions and delocalized electrons

D. Sharing of electrons between atoms and electrostatic attraction between ions

10. The formula of cerium(III) sulfate is Ce2(SO4)3. What is the correct formula of cerium(III) phosphate?

A. CeP

B. Ce2(PO4)3

C. Ce3(PO4)2

D. CePO4




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