Download IJSO Question Paper 2008 (MCQ) PDF

TitleIJSO Question Paper 2008 (MCQ)
TagsAcid Mole (Unit) Acid Dissociation Constant Phase (Matter) Titration
File Size506.7 KB
Total Pages17
Document Text Contents
Page 8

a. Light rays travel straight.

b. Sunlight rays falling on the Earth are parallel to each other.

c. Earth has a spherical shape.


Test Competition, 5th IJSO, Gyeongnam, Korea, December 9, 2008

9. The most abundant element in the atmosphere of Jupiter is hydrogen. The Earth’s atmosphere has

a very small amount of hydrogen. Choose an answer which includes all the correct statements. The

hydrogen amount is different because -

a. the temperature of a planet’s atmosphere is lower as the planet is farther away from the sun.

b. the mass of Jupiter is significantly larger than the mass of Earth.

c. hydrogen has escaped out of the Earth’s atmosphere.

d. most of the hydrogen is contained inside Earth in the form of chemical compounds.
(A) a (B) a, b (C) a, b, c (D) a, b, c, d

10. In 3rd century BC, Eratosthenes observed the shadows of objects in Alexandria and in Syene at

noon of the summer solstice. He observed that the sunlight inclined 7.2° from the vertical in

Alexandria, while 0° from the vertical in Syene. He calculated the radius of Earth from this result.

Which of the following is the correct combination of assumptions that he used?

(A) a and b only (B) a and c only (C) b and c only (D) all of the above

11. How much current is needed to produce 10000 kg/day of Fe metal from molten Fe2O3? The

atomic weights of Fe and O are 55.85 and 16.00, respectively. A mole of electrons has a charge of

96500 Coulomb (Faraday’s constant).

(A) 6 x 102 A

(B) 6 x 103 A

(C) 6 x 104 A

(D) 6 x 105 A

12. An element X is the second most abundant in the Earth’s crust by mass. Quartz is one of its

oxide forms. What is this element?

(A) silicon (B) carbon (C) aluminum (D) magnesium

13. A phase diagram shows pressure and temperature conditions at which stable phases can occur.

The figure below is the phase diagram of CO2. Which of the following is an incorrect statement,

based on this diagram? (1 atm =1.01325 x 105 Pa, 1 atm = 1.01325 bar)

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Page 9

Test Competition, 5th IJSO, Gyeongnam, Korea, December 9, 2008

(A) X is the triple point of CO2, where three different phases coexist.

(B) C is the critical point of CO2, where liquid and gaseous phases become indistinguishable.

(C) Under the atmospheric pressure, gaseous CO2 can be liquid when the temperature is reduced.

(D) At room temperature (25 C), gaseous CO2 can be liquid when the pressure increases.

14. Gaseous ammonia (NH3) can be decomposed to gaseous N2 and gaseous H2. What are the

volumes of gaseous N2 and H2 when 17.0 mL of gaseous NH3 is completely decomposed? Assume

that the pressure and temperature of the reaction flask are kept constant. Gases are assumed to be

ideal gases. (mL = milliliter)

Volume of N2 Volume of H2

(A) 8.50 mL 25.5 mL

(B) 17.0 mL 34.0 mL

(C) 25.5 mL 51.0 mL

(D) 17.0 mL 51.0 mL

15. The first ionization energy (IE1) of an element is defined by the minimum energy needed to

remove an outermost valence electron from its atomic ground state in gas phase. Which of the

following elements has the largest IE1? The ground state electron configuration of each element is

shown in the parenthesis.

(A) B ( 1s22s22p1 ) (B) C ( 1s22s22p2 ) (C) N ( 1s22s22p3 ) (D) O ( 1s22s22p4 )

16. The reaction between calcium carbonate (CaCO3, molar mass 100) and gaseous hydrogen

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