Grade 8----Chapter 7 Acids, Bases And pH
50 points.
Questions and Answers
- 1.
Step 1: After you have completed the test, you may try to do some extra credit (1/2 point for each correct problem) on Balancing Equations. Here is the website: http://chemistry.about.com/od/chemicalequations/l/blbalancequiz.htm?lastQuestion=3&answers=3&submit=Next+Question+%3E%3E&ccount=1You can also access the website labeled Ch 6 Balancing Equations on my Chemistry page of the Z- Web Network. Step 2: Work on your Final Exam Study Guide
- 2.
In this test you will not be able to navigate back and forth between questions. All of your work will be saved as you move forward in the test. However, please take your time in reviewing your answer before selecting it. You can not go backwards on the test. I will be coming around for the Binder Check and to check your pH lab. Please do not talk during the test. Thank you and Good Luck! Z
- 3.
Which one of the following is an acid?
- A.
Lemon Juice
- B.
Salt Solution
- C.
Bleach
- D.
Water
Correct Answer
A. Lemon JuiceExplanation
Lemon juice is an acid because it contains citric acid, which gives it a sour taste. Acids are substances that release hydrogen ions when dissolved in water, and lemon juice is acidic due to the presence of citric acid.Rate this question:
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- 4.
Acids and alkalis can cause some dyes to change color. These dyes are called...
- A.
Solutions
- B.
Mixtures
- C.
Indicators
- D.
Solvents
Correct Answer
C. IndicatorsExplanation
Acids and alkalis can cause dyes to change color, and the dyes that are specifically designed to undergo this color change are called indicators. Indicators are substances that change color depending on the pH of the solution they are in. They are commonly used in chemistry to determine whether a solution is acidic or alkaline. Therefore, indicators are the correct answer in this context.Rate this question:
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- 5.
What color does Universal indicator (the cabbage solution) turn in strong acid?
- A.
Orange
- B.
Green
- C.
Blue
- D.
Red
Correct Answer
D. RedExplanation
Universal indicator is a pH indicator that changes color depending on the acidity or alkalinity of a solution. In the presence of a strong acid, the cabbage solution, which is used as a universal indicator, turns red. This indicates a low pH level, as strong acids have a high concentration of hydrogen ions. Therefore, the correct answer is red.Rate this question:
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- 6.
Some acids should be treated very carefully. This is because....
- A.
They are red.
- B.
They are corrosive.
- C.
They taste sour.
- D.
None of these.
Correct Answer
B. They are corrosive.Explanation
Some acids should be treated very carefully because they are corrosive. This means that they have the ability to cause damage or destruction to materials they come into contact with. Corrosive acids can cause chemical burns, damage to skin and eyes, and can even be harmful if inhaled or ingested. Therefore, it is important to handle them with caution, wear protective gear, and follow proper safety protocols to avoid any accidents or injuries.Rate this question:
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- 7.
Which piece of safety equipment should always be worn when handling acids and alkalis?
- A.
Tongs
- B.
Tripod
- C.
Gauze
- D.
Safety Goggles
Correct Answer
D. Safety GogglesExplanation
When handling acids and alkalis, it is crucial to wear safety goggles. This is because acids and alkalis can be extremely corrosive and can cause severe damage to the eyes if they come into contact. Safety goggles provide a protective barrier that shields the eyes from any splashes or spills that may occur during the handling process. Wearing safety goggles ensures the safety and well-being of the individual by minimizing the risk of eye injuries.Rate this question:
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- 8.
A bee sting is acidic. To neutralize the pain, which of these substances could you put onto it?
- A.
Vinegar
- B.
Baking Soda
- C.
Lemon Juice
- D.
Water
Correct Answer
B. Baking SodaExplanation
Baking soda is a basic substance, also known as sodium bicarbonate. When applied to a bee sting, it can help neutralize the acidic venom and provide relief from the pain. This is because baking soda has alkaline properties that can counteract the acidity of the sting.Rate this question:
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- 9.
One substance that can be used to make an indicator is:
- A.
Vinegar
- B.
Orange Juice
- C.
Red Cabbage
- D.
Soap
Correct Answer
C. Red CabbageExplanation
Red cabbage can be used to make an indicator because it contains a pigment called anthocyanin, which can change color depending on the pH of the solution it is in. When the cabbage juice is added to an acidic solution, it turns pink or red, while in a basic solution it turns green or blue. This property makes red cabbage a suitable substance for creating an indicator to test the acidity or alkalinity of other substances.Rate this question:
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- 10.
Which of the following substances would corrode metal the most?
- A.
Sulfuric Acid
- B.
Salt Solution
- C.
Lemon Juice
- D.
Vinegar
Correct Answer
A. Sulfuric AcidExplanation
Sulfuric acid is a highly corrosive substance that can react with metals, causing them to corrode. It is a strong acid that can easily break down the protective oxide layer on the surface of metals, exposing them to further oxidation and corrosion. In comparison, salt solution, lemon juice, and vinegar are relatively less corrosive and would not cause as much damage to metals.Rate this question:
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- 11.
Alkalis can be dangerous as acids. Which of the following substances is the strongest alkali?
- A.
Hydrochloric Acid
- B.
Soap
- C.
Sodium Hydroxide/Bleach
- D.
Toothpaste
Correct Answer
C. Sodium Hydroxide/BleachExplanation
Sodium hydroxide/bleach is the strongest alkali among the given substances. Alkalis are substances that can neutralize acids, and sodium hydroxide is a strong alkali that is commonly used in cleaning products like bleach. It has a high pH level and can cause severe burns and damage to the skin and eyes if not handled properly. Hydrochloric acid is an acid, not an alkali, and is not as strong as sodium hydroxide. Soap and toothpaste may have some alkaline properties, but they are not as strong as sodium hydroxide.Rate this question:
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- 12.
The pH scale measures:
- A.
The strength of an acid.
- B.
The strength of hydrogen ions.
- C.
The concentration of hydrogen ions.
- D.
The concentration of an acid.
Correct Answer
C. The concentration of hydrogen ions.Explanation
The pH scale measures the concentration of hydrogen ions in a solution. It indicates the level of acidity or alkalinity of a substance. A lower pH value indicates a higher concentration of hydrogen ions, making the substance more acidic. Conversely, a higher pH value indicates a lower concentration of hydrogen ions, making the substance more alkaline. Therefore, the correct answer is the concentration of hydrogen ions.Rate this question:
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- 13.
You can find the pH of a substance by using...
- A.
Plain paper
- B.
A thermometer
- C.
Litmus indicator
- D.
A conductivity tester
Correct Answer
C. Litmus indicatorExplanation
A litmus indicator can be used to determine the pH of a substance because it is a pH indicator. Litmus paper changes color depending on the acidity or alkalinity of a solution. When the litmus paper turns red, it indicates that the substance is acidic, while a blue color indicates alkalinity. By observing the color change of the litmus paper after it comes into contact with a substance, one can determine its pH level.Rate this question:
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- 14.
Which is a characteristic property of acids?
- A.
They turn blue litmus paper red.
- B.
They turn red litmus paper blue.
- C.
They taste bitter.
- D.
They do not react with metals.
Correct Answer
A. They turn blue litmus paper red.Explanation
Acids are known to turn blue litmus paper red. This is because acids release hydrogen ions (H+) when dissolved in water, which react with the blue litmus paper and cause it to change color from blue to red. This is a characteristic property of acids and can be used to identify their presence.Rate this question:
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- 15.
Which is a likely use for a base?
- A.
As a vitamin in your food.
- B.
Making foods taste sour.
- C.
Etching metals for printing.
- D.
Making soaps and detergents.
Correct Answer
D. Making soaps and detergents.Explanation
A base is commonly used in the production of soaps and detergents. Bases, also known as alkaline substances, are used in these products to help remove dirt and grease. They react with fats and oils to form soap molecules, which can then be used for cleaning purposes. The other options listed, such as being a vitamin in food or making foods taste sour, do not typically involve the use of bases. Etching metals for printing may involve the use of acids, rather than bases.Rate this question:
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- 16.
In a water solution, how do acids differ from bases?
- A.
Acids form hydrogen ions (H+), while bases form hydroxide ions(OH-).
- B.
Acids turn litmus blue, while bases turn litmus red.
- C.
Acids form salts, but bases do not.
- D.
Hydrogen ions (H+) remain dissolved, but hydroxide ions (OH-) do not.
Correct Answer
A. Acids form hydrogen ions (H+), while bases form hydroxide ions(OH-). -
- 17.
In water, bases form
- A.
Hydroxide ions
- B.
Hydrogen ions
- C.
Hydrogen gas
- D.
Oxide ions
Correct Answer
A. Hydroxide ionsExplanation
In water, bases form hydroxide ions. When a base is dissolved in water, it dissociates to release hydroxide ions (OH-) into the solution. These hydroxide ions can accept a hydrogen ion (H+) from an acid, forming water (H2O) and neutralizing the acidic solution. This process is known as neutralization. Therefore, the correct answer is hydroxide ions.Rate this question:
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- 18.
Neutralization is a reaction between a(n)...
- A.
Acid and a base
- B.
Acid and a metal
- C.
Base and salt
- D.
Salt and water.
Correct Answer
A. Acid and a baseExplanation
Neutralization is a reaction between an acid and a base. In this reaction, the acid donates a proton (H+) to the base, forming water and a salt. The acid loses its acidic properties by losing a proton, while the base loses its basic properties by accepting the proton. This reaction results in the formation of a neutral solution, where the pH is close to 7.Rate this question:
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- 19.
Acids are described as "corrosive" because they....
- A.
Turn litmus blue
- B.
Taste bitter
- C.
"eat away" at other materials
- D.
Feel slippery.
Correct Answer
C. "eat away" at other materialsExplanation
Acids are described as "corrosive" because they have the ability to chemically react with and degrade other materials. This process is commonly referred to as "eating away" at other materials. Acids can cause damage and destruction to substances they come into contact with, making them highly corrosive.Rate this question:
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- 20.
Which does NOT belong:
- A.
Coke
- B.
Lemon
- C.
Baking Soda
- D.
Vinegar
Correct Answer
C. Baking SodaExplanation
The given options include Coke, Lemon, Baking Soda, and Vinegar. Coke, Lemon, and Vinegar are all acidic substances commonly used in cooking or cleaning. Baking soda, on the other hand, is a basic substance often used as a leavening agent in baking. Therefore, Baking Soda does not belong in this group of acidic substances.Rate this question:
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- 21.
Which does NOT belong:
- A.
Apple Juice pH 5
- B.
Ammonia pH 8
- C.
Tums/Rolaids pH 9
- D.
Shampoo/conditioner pH 7.5
Correct Answer
A. Apple Juice pH 5Explanation
The given options consist of different substances and their corresponding pH levels. Apple Juice with a pH of 5 is the correct answer because it is the only acidic substance among the options. Ammonia has a pH of 8, Tums/Rolaids has a pH of 9, and Shampoo/conditioner has a pH of 7.5, all of which are either neutral or alkaline.Rate this question:
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- 22.
What is the pH of a neutral substance?
- A.
5
- B.
6
- C.
7
- D.
8
Correct Answer
C. 7Explanation
The pH scale is a measure of the acidity or alkalinity of a solution. It ranges from 0 to 14, where 0 is highly acidic, 7 is neutral, and 14 is highly alkaline. A neutral substance has a pH of 7, which means it is neither acidic nor alkaline. Therefore, the correct answer is 7.Rate this question:
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Mar 14, 2023Quiz Edited by
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Jan 14, 2015Quiz Created by
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