Chemistry By Jocelyn Ventura

25 Questions | Total Attempts: 371

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Chemistry Quizzes & Trivia

Multiple choice


Questions and Answers
  • 1. 
    A glowing match was dropped into a dry gas jar containing one gas only. The match (but not the gas) caught a light.     Which gas is most likely present in the jar?  
    • A. 

      A. oxygen

    • B. 

      B. hydrogen

    • C. 

      C. Carbon dioxide

    • D. 

      D. Carbon monoxide

  • 2. 
     Which statement does NOT correctly describe a salt?  
    • A. 

      A. It is a compound

    • B. 

      B. It is a pure substance

    • C. 

      C. It always contains oxygen

    • D. 

      D. It is a chemical combination of a metal and a non-metal

  • 3. 
     Which information gives the composition of a compound?
    • A. 

      A. kind of element present

    • B. 

      B. kind and amount of element present

    • C. 

      C. kind and volume of elements present

    • D. 

      D. amount and volume of the elements present

  • 4. 
     Which statement correctly distinguishes between an element and a compound?  
    • A. 

      A. An element is homogeneous while a compound is a heterogeneous.

    • B. 

      B. An element has a sharp melting point while a compound melts over a temperature range.

    • C. 

      C. An element gains mass when heated in the presence of air while a compound loses mass when heated in the presence of air.

    • D. 

      D. An element is a one phase system while a compound is a two phase system.

  • 5. 
     To which does the law of definite composition apply?  
    • A. 

      A. a sample of ice

    • B. 

      B. a pure sample of copper

    • C. 

      C. a solution of salt in water

    • D. 

      D. a mixture of oxygen gas and nitrogen gas

  • 6. 
     A clear, colorless liquid boils sharply at 80.1 ̊C. It is soluble in alcohol. It burns when ignited. Analysis shows it has a       definite composition: 92% carbon and 8% hydrogen by mass. Which properties of the liquid show it is a compound, NOT      a mixture?  
    • A. 

      A. It is a liquid and burns

    • B. 

      B. it is clear and colorless

    • C. 

      C. it is soluble in alcohol and burns

    • D. 

      D. It boils sharply and has a definite composition

  • 7. 
     Which property of water do you expect NOT to change when salt is added to it?
    • A. 

      A. its density

    • B. 

      B. its freezing point

    • C. 

      C. its boiling point

    • D. 

      D. its non flammability

  • 8. 
     . Calcium combines with sulfur in a mass ratio of 5:4. If 10g each of Calcium and Sulfur are mixed and heat is applied in a      closed vessel, what will remain unreacted after the reaction?  
    • A. 

      A. 6 g Sulfur

    • B. 

      B. 2 g Sulfur

    • C. 

      C. 2 g Calcium

    • D. 

      D. 6 g Calcium

  • 9. 
    Elements A and B reacted to form compound AB. The data obtained by four students are shown in the table. What       general statement INCORRECTLY describe the data given in the table? STUDENT MASS of A (g) MASS of B (g) MASS AB (g) 1 1.0 0.5 1.5 2 1.4 0.7 2.1 3 1.8 0.9 2.7 4 2.0 1.0 3.0
    • A. 

      A. AB has no definite composition.

    • B. 

      B. AB is made up of two parts of A and one part B by mass.

    • C. 

      C. The sum of the masses of A and B equals the mass of AB.

    • D. 

      D. The elements A and B combined in definite proportion by mass in forming AB.

  • 10. 
    Which of the following should you NOT do when preparing herbal medicines from plant leaves?  
    • A. 

      A. Use aluminium pots

    • B. 

      B. Use only fresh, clean leaves

    • C. 

      C. store in brown-colored bottles

    • D. 

      D. apply low heat for a longer period

  • 11. 
    Two substances were made to react in a cloud vessel. Which will remain the same before and after the reaction?  
    • A. 

      A. mass of the product

    • B. 

      B. mass of the reactants

    • C. 

      C. temperature of the vessel.

    • D. 

      D. total mass of reactants and products

  • 12. 
     Powdered copper when heated in an atmosphere of oxygen produces copper (II) oxide according to the chemical equation.             2Cu + O₂ ----------->   2 Cu O               What is the mass of copper (II) oxide that forms?  
    • A. 

      A. The same as the mass of copper.

    • B. 

      B. Twice the mass of oxygen that combined with copper

    • C. 

      C. The sum of the masses of copper and oxygen that combined.

    • D. 

      D. The sum of twice the mass of copper and the mass of oxygen that combined.

  • 13. 
     Given the chemical equation A + B  ---------->C + D. If the masses of A, B, and C are given, how do you determine the mass of D?
    • A. 

      A. Multiply the mass of C by 2

    • B. 

      B. Add the masses of A, B, and C.

    • C. 

      C. Add the masses of A and B, and subtract the mass of C

    • D. 

      D. Add the masses of A and B, and subtract from the mass of C.

  • 14. 
    A weighed amount of copper was heated in the presence of air. Its color was observed to turn reddish black. On cooling,       the material was weighed again. How does the mass after heating compare with the mass before heating?  
    • A. 

      A. It is greater than the mass before heating.

    • B. 

      B. it is less than the mass before heating

    • C. 

      C. It can not be predicted

    • D. 

      D. They are the same.

  • 15. 
    The law illustrated in item No.15 is __________________
    • A. 

      A. Dalton’s Law

    • B. 

      B. law of mass Conservation

    • C. 

      C. Law of Multiple Proportion

    • D. 

      D. law of Definite Composition

  • 16. 
    In the reaction: A + B--------> C, 10g of A reacted with B to produce 25 g of C. the mass of B that reacted is ____________.  
    • A. 

      A. 10 g

    • B. 

      B. 15 g

    • C. 

      C. 25 g

    • D. 

      D. 35 g

  • 17. 
     What is conserved in a chemical reaction?
    • A. 

      A. Number of molecules of reactants

    • B. 

      B. Chemical composition

    • C. 

      C. Volume

    • D. 

      D. mass

  • 18. 
    Analysis shows ammonia to contain 14 g of nitrogen for every 3.0 g of hydrogen. How many grams of nitrogen are       needed to react with 0.15 g hydrogen to produce ammonia?  
    • A. 

      A. 0.30 g

    • B. 

      B. 0.50 g

    • C. 

      C. 0.70 g

    • D. 

      D. 0.90 g

  • 19. 
    Why can’t you change the formula of  a compound in order to balance a reaction?  
    • A. 

      A. The elements that combine have definite composition and fixed proportion of elements by mass.

    • B. 

      B. The number of atoms in the left should be equal to the atoms on the right of the arrow.

    • C. 

      C. The elements have definite mass ratios.

    • D. 

      D. The molecules are indestructible.

  • 20. 
    Exactly 24 g of a silvery white substances was completely burned in an open vessel. A grey ash was formed. The ash      was found to be 40 g. What does this indicate?  
    • A. 

      A. The substance combined with another element to form a compound.

    • B. 

      B. The substance decomposed and became ash after burning.

    • C. 

      C. The substance is a compound.

    • D. 

      D. The substance is impure.

  • 21. 
    . Consider the following reactions:      a. White crystal --------->   black solid + colorless gas      b. Very dark violet crystal  ------------> violet gas  ------------> fine violet crystals      c. Red powder ----------> Silvery liquid + colorless gas            Which reactant is an element?  
    • A. 

      A. the white crystal

    • B. 

      B. the dark violet crystal

    • C. 

      C. the red powder

    • D. 

      D. white crystal and red powder

  • 22. 
     Which carries the current in an electrolytic conductor?
    • A. 

      A. molecules

    • B. 

      B. electrons

    • C. 

      C. atoms

    • D. 

      D. ions

  • 23. 
     Dalton’s Atomic Theory explains the laws of chemical changes. Which of Dalton’s assumptions explains the Law of        Conservation of Mass?  
    • A. 

      A. An atom is the smallest particle of an element.

    • B. 

      B. Atoms combine in ratios of small whole numbers.

    • C. 

      C. Atoms of a given element have the same properties of size, shape and mass.

    • D. 

      D. In an ordinary chemical reactions, no new atoms are created and no old ones are destroyed.

  • 24. 
    Calcium combines with sulfur in a mass ratio of 5:4. If 10 g each of Calcium and sulfur are mixed and heat is applied in        a closed vessel, a) What will remain unreacted after the reaction?   
    • A. 

      A. 2 g Sulfur

    • B. 

      B. 2 g Calcium

    • C. 

      C.6 g Sulfur

    • D. 

      D. 6 g Calcium

  • 25. 
    . Calcium combines with sulfur in a mass ratio of 5:4. If 10 g each of Calcium and sulfur are mixed and heat is applied in        a closed vessel.   What element all consumed during the chemical reaction? 
    • A. 

      A. Sulfur

    • B. 

      B. Calcium

    • C. 

      C. Sulfur and Calcium

    • D. 

      D. Calcium and Sulfide

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