Coverage: 1st Summative
1. Which description best fits an acid?
A. a substance that produces hydroxide ions in water and usually has pH greater than 7
B. a substance that produces hydrogen ions in water and usually has pH lower than 7
C. an apparatus used to measure the mass of a solution
D. a number placed in front of a formula in a chemical equation
2. Which description best fits a base?
A. a substance that always has pH lower than 7
B. a substance that is always a neutral salt solution
C. a symbol that means produces in a chemical equation
D. a substance that produces hydroxide ions in water and usually has pH greater than 7
3. Which common substance is an example of an acid?
A. vinegar | C. sodium hydroxide solution |
B. soap solution | D. saline solution |
4. Which common substance is an example of a base?
A. vinegar | C. soap solution |
B. calamansi juice | D. table salt dissolved in water |
5. A sample has pH
3. Which classification is most appropriate?
A. basic | C. balanced equation |
B. neutral | D. acidic |
6. A sample has pH
10. Which classification is most appropriate?
A. acidic | C. neutral |
B. basic | D. salt formula |
7. What is the main use of an indicator such as litmus paper or turmeric extract?
A. to change subscripts in a formula
B. to count the atoms in a chemical equation
C. to provide evidence whether a solution is acidic, basic, or neutral
D. to turn every salt into an acid
8. A learner has four clear household solutions. Why should the learner not classify them only by appearance?
A. Different acids, bases, and salts may look similar, so indicator or pH evidence is needed.
B. Clear solutions are always acids.
C. Clear solutions are never chemicals.
D. Appearance automatically gives the exact pH.
9. In a chemical equation, what are reactants?
A. the substances formed on the right side of the arrow
B. the numbers written after element symbols
C. the paper strips used as indicators
D. the starting substances found on the left side of the arrow
10. In a chemical equation, what are products?
A. the starting substances on the left side
B. the new substances formed and written on the right side of the arrow
C. the pH values of acids
D. the colors of litmus paper only
11. What does the arrow (->) mean in a chemical equation?
A. yields or produces | C. is divided by |
B. is less than | D. is the pH scale |
12. Which word equation correctly describes iron reacting with oxygen to form iron(III) oxide?
A. iron(III) oxide -> iron + oxygen | C. iron + oxygen -> iron(III) oxide |
B. iron + pH -> oxygen | D. indicator + iron -> base |
13. Which statement correctly describes a skeleton equation?
A. It uses only pictures and no chemical formulas.
B. It uses chemical formulas but may not yet show the correct proportions of reactants and products.
C. It is always fully balanced.
D. It is a pH scale for acids and bases.
14. In 2H2O, what is the coefficient?
A. 2 after H | C. H |
B. O | D. 2 before H2O |
15. In H2O, what does the subscript 2 show?
A. There are two hydrogen atoms in one water molecule.
B. There are two oxygen atoms in one water molecule.
C. The formula is automatically balanced.
D. The pH of water is 2.
16. Why do scientists use chemical equations?
A. to replace laboratory safety rules
B. to identify acids by taste
C. to describe chemical reactions concisely using names, symbols, or formulas
D. to remove products from reactions
17. Which is the first useful step in balancing a chemical equation?
A. change the subscripts immediately
B. erase the products
C. classify the solution by smell
D. count the atoms of each element on the reactant and product sides
18. Which number should be changed when balancing an equation?
A. coefficient | C. element symbol |
B. subscript | D. pH meter |
19. Why should subscripts not be changed when balancing a chemical equation?
A. Subscripts are the same as pH values.
B. Subscripts are only laboratory tools.
C. Changing a subscript changes the chemical formula and the substance represented.
D. Changing a subscript always makes a salt.
20. Which equation is the balanced form of H2 + O2 -> H2O?
A. H2 + O2 -> 2H2O | C. H2 + 2O2 -> H2O |
B. 2H2 + O2 -> 2H2O | D. 2H2 + 2O2 -> H2O |
21. Which equation is the balanced form of Na + O2 -> Na2O?
A. 4Na + O2 -> 2Na2O | C. Na + O2 -> Na2O |
B. 2Na + O2 -> Na2O | D. Na + 2O2 -> 2Na2O |
22. In CH4 + 2O2 -> CO2 + 2H2O, how many oxygen atoms are on the product side?
A. 2 | C. 6 |
B. 3 | D. 4 |
23. What does a balanced chemical equation show?
A. Reactants disappear completely.
B. The same number of each type of atom is present on both sides of the equation.
C. Products have no atoms.
D. Mass is created after the arrow.
24. In a reaction, methane and oxygen form carbon dioxide and water. Which statement best explains what happens to the atoms?
A. The atoms disappear after reacting.
B. The atoms become pH meters.
C. The atoms split and recombine into new substances without being created or destroyed.
D. The atoms turn into unrelated elements not shown in the equation.
25. Which equation is balanced?
A. AgNO3 + KCl -> AgCl + KNO3 | C. Na + O2 -> Na2O |
B. H2 + O2 -> H2O | D. Al + O2 -> Al2O3 |
1ST SUMMATIVE TEST IN SCIENCE GRADE 10
SET A
Key to Correction
1. B | 6. B | 11. A | 16. C | 21. A |
2. D | 7. C | 12. C | 17. D | 22. D |
3. A | 8. A | 13. B | 18. A | 23. B |
4. C | 9. D | 14. D | 19. C | 24. C |
5. D | 10. B | 15. A | 20. B | 25. A |