Target: 10 Questions in 10 minutes

An IB Chemistry data booklet is helpful
1. Which of the following statements about mixtures is true?
  • A.   Mixtures have a fixed composition
  • B.   Differences in physical properties are used to separate components of a mixture
  • C.   The components in a mixture are chemically combined
  • D.   Mixtures can be represented by a chemical formula
2. Which of the following is NOT a homogeneous mixture?
  • A.   oil and water
  • B.   stainless steel
  • C.   ethanol and water
  • D.   unpolluted air
3. Select an appropriate method for obtaining crystals of potassium chloride from its aqueous solution:
  • A. simple distillation
  • B. filtration
  • C. paper chromatography
  • D. solvation
4. Thin layer chromatography can be used to analyse amino acids in the pharmaceutical industry. Which of the following amino acids has an Rf value of 0.5?

amino acid chromatography

  
  • A. amino acid A
  • B. amino acid B
  • C. amino acid C
  • D. amino acid D
5. Which statement describes a compound?
  • A.   a compound consists of atoms of the same element.
  • B.   in a compound, the elements are physically bonded together.
  • C.   in a compound, the elements are present in a fixed ratio.
  • D.   the elements in a compound can be separated by physical methods.
6. Bromine has a melting point of -7.05oC and a boiling point of 58.8oC . At which temperature is bromine a liquid?
  • A.   200 K
  • B.   250 K
  • C.   300 K
  • D.   350 K

 
7. What is the name given to the change of state represented by the following equation?

   CO2(g) ⇌ CO2(s)

  • A.   condensation
  • B.   deposition
  • C.   freezing
  • D.   sublimation

8. Which of the following occur as steam condenses to water?

I. The kinetic energy of the particles increases
II. The distance between the particles increases
III. The temperature remains constant
 
  • A.   I and II only
  • B.   I and III only
  • C.   II and III only
  • D.   III only

9. Which of the following graphs best represents the cooling curve when a pure substance with a melting point of 50°C is cooled from 75°C to room temperature?

cooling curve graphs x4
10. Which of these changes of state is endothermic?
  • A.   H2O(g)  →  H2O(l)
  • B.   I2(s) → I2(g)
  • C.   Na(l)  →  Na(s)
  • D.   2C6H6(l) + 15O2(g) →   12CO2(g) + 6H2O(l)