Study Guide – 1st Semester Benchmark Exam 2016-17 Name: KEY – MRS SMITH
1. Characteristics of an Acid / 2. Characteristics of a BaseTastes sour
Turns blue litmus paper red
Reacts with metals – produces a gas
Reacts with carbonates- produces a gas / Tastes bitter and feels slippery
Turns red litmus paper blue
Does not react with metals or carbonates
3. What is an indicator? What indicators are used to identify acids and bases?
An indicator is a compound that changes color when it comes in contact with an acid or base.
Litmus paper is used to identify acids and bases. (shows us by color change)
pH paper is used to identify the exact pH of a substance.
4. What is the pH scale? How do scientists use the pH scale?
The pH scale is a numeric scale with values from 0-14. Scientists use it to identify strong and weak acids and bases and also to express the concentration of hydrogen ions in a solution.
5. A. Label the Acid side of the scale.B. Label the base side of the pH scale. C. Label Neutral
D. Add the following substances to the scale based on their pH.
i. Stomach acid (1)ii. Lemon juice (2)iii. Soda (4)iv. Saliva (6)v. Water (7)
vi. Baking soda (9)vii. Antacids (10)viii. Oven cleaner(13)
0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14Acids are getting __stronger___Bases are getting _stronger
6. What range of numbers on the pH scale identifies bases? 8-14
7. What range of numbers on the pH scale identifies acids? 0-6
8. Look at the scale above, which substance is an example of a strong acid? How do you know this?
Stomach acid is a strong acid because it registers a 1 on the pH scale.
9. Look at the scale above, which substance is an example of a strong base? How do you know this?
Oven cleaner is a strong base because it registers a 13 on the pH scale.
10. Complete the “Litmus Paper Poem”Complete the “pH scale poem.”
Acids turn blue litmus paper _redAcids are found on the __left
Bases turn red litmus paper blue Bases are found on the _right
Neutrals make the paper stay the _same Neutral is in the _middle
They show up on the pH scale too.The colors are really bright.
11. Label the anatomy of the chemical equation. – reactants, products, coefficient, subscripts, compounds, element.
ReactantsProductssubscript
2CuO + C 2Cu + CO2
Coefficientelementcompound
12. What does the law/principle of conservation of mass state?
The law of conservation of mass states that matter cannot be created nor destroyed. OR
The total mass of the products are the same as the mass of the reactants OR the amount of matter is the same at the beginning and the end of a reaction.
13. How does the law of conservation of mass apply to the above equation?
The law applies because the reactants can be found in the products. They are just in a different combination. Matter has not been lost. Cu, O and C are found in the products, just their combinations have changed.
When investigating changes to a war memorial statue, students saw the statue had rusted. The product of the reaction was Fe2O3.
14. Is the formation of rust a physical or chemical change? Why?Rust formation is a chemical change because a new substance is formed.
15. If Fe2O3 is the product, which of the following chemical equations explains the reaction?
a. 4Fe + 3O2Fe2O3b. 4Fe + CO2 Fe2O3 c. 4Fe + 2H2O 2Fe2O3
A is the correct answer because in b. there is a C for carbon, and in c. there is a H for hydrogen.
16. Is the formation of rust a synthesis or decomposition reaction? Justify your answer.
The formation of rust is a synthesis reaction because a new substance is produced. Also two simpler substances combine to form a more complex substance. A+B=AB
17. Classify the following equations and then justify your classification.
A. Na + Cl NaCl Synthesis – because the two reactants Na and Cl have combined to form a
more complex product, NaCl.
B. Fe + H2O --> Fe3O4 + H2 Single replacement – because the O has switched from the H to the Fe.
C. CaCO3 CaO + CO2 Decomposition – the reactant, CaCO3 has broken down to form two
simpler products, CaO and CO2.
D. Na2SO4 + CaCl2 -->NaCl + CaSO4 Double replacement – the Cl switches from the Ca
to the Na and the SO4 switches from the Na to the Ca.
18.Characteristics of a Physical Change / 19. Characteristics of a Chemical Change- Form or appearance changes
- Composition stays the same
- Can usually be reversed
- No new substance is formed
- Remember – boiling water is a physical change
- Evaporation, condensation and precipitation – changes in states of matter
New composition
New substances are formed
Not easily reversed
Signs that are evidence of a chemical change:
1. Color
2. Energy – temperature change and light
3. Odor
4. Gases or solids
20. Classify the following examples as physical or chemical changes and JUSTIFY your answer.
a. Melting snowphysicalb. Burning a match chemical
c. Rusting statue chemicald. Making a paper snowflake physical
21. a. Define elementb. Define compound
An element is matter in its simplestA compound forms when two or more
form – cannot be broken down anyelements are combined.
further.
22. Classify the following as elements –E or compounds –C. Write the correct letter next to the symbols.
a. HElementb. H2OCompoundc. NaClCompoundd. OElement
23. Classify the characteristics – M for metal or NM for nonmetal or B for Both.
a. Good conductor of heat and electricity. metal b. Will react or bond with nonmetals Both
c. Are found on the PTE.Bothd. Found to the right of the zigzag line.NM
e. Found to the left of the zig zag line. metalsf. Poor conductors of heat & electricity.NM
g. Most are solid at room temperature.metalsh. Includes all three states of matter. NM
i. Malleable and ductilemetalsj. Dull and brittleNM
24. Name 8 patterns found on the PTE. Attach your notes if you have them as well.
Metals are found on the left of the zigzag line, Nonmetals are found to the right of the zigzag line, Most reactive elements are on the left side, Valence electron pattern 1 to 8 then 1to 8, columns are called families, rows are called periods, families have similar characteristics based on valence electrons, colors used to classify the elements.
25. How is the modern PTE organized? By increasing Atomic Number
26. What can we learn from the PTE?How elements are classified and how they will react (bond) with other elements. The characteristics of different elements based on their placement on the PTE.
27. What is the significance/importance of a column on the PTE?The elements in the family share similar properties based on the number of valence electrons.
28. Why is hydrogen in family 1? Hydrogen is in family 1 even though it is a nonmetal because it has one valence electron so it “behaves” like the elements in family 1. –willing to bond.
29. a. How may periods?7b. How many families? _18 – also called groups
Rows or columns?_Rows__Rows or columns? _columns_
30. The atomic number tells us the number of _protons andelectrons in the atom of an element.
31. The valence electrons are responsible for reacting/bonding with other atoms.
32. The _protons and _electrons are found in the nucleus of an atom.
35. Look at the chemical formulas below. What type of bond has formed?
a. C6H12O6 - covalentb. NaBr- ionicc. H2O- covalentd. MgO - ionic
36. In the table define qualitative and quantitative data. Give two examples for each.
Characteristics of Quantitative Data / Characteristics of Qualitative DataData that shows “how many” - quantity
Measurement data - NUMBERS
How many plants grew in the ecosystem? 10 / Data collected that shows the “quality” of the results
Usually observations – L – LOOK – 0bserve/describe
Which tea tasted better? Rate each one – Excellent – Good – Terrible
37. Classify the following statements as qL or qN data statements.
QN There are 2 dogs in the yard _QLMy blue shirt is darker than her blue shirt
QN I picked up 20 rocks at the creek_QLSome rocks were larger than others
QL Papa Johns pizza is better than DominosQN I ate 4 pieces of pizza
38.
What is an inference? / What is a prediction? / What is an observation?An educated guess that requires using previous experiences/knowledge.
Inferences are usually made in response to an observation.
We see someone frown at us we infer they are unhappy with us. / A statement that tells what may happen in the future.
I predict that more seeds will germinate and live successfully in ecosystem A because plants need more room to grow, and so there will not be competition for resources. / A description using the senses.
We see the road is wet.
We hear loud noise.
Usually after an observation, we make an inference to explain what we saw or heard.
The road is wet, it must have rained.
39. Identify the following statements as Inferences (I), Predictions (P), or Observations (O).
O_A. Elephants have a long trunk and large ears.
P_B. Elephants will be extinct if hunters keep poaching them for their tusks.
I C. Elephants are one of the strongest animals in the world because they are so large.
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