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EXPERIMENT XX Solutions
$10.00EXPERIMENT XX
Measurements
Materials and Equipment: Digital balance (0.01g precision); thermometer; 150mL and 250mL beakers; Teaspoon; 1 Cup Measuring Cup; Coffee Mug; 10mL and 100mL graduated cylinders; watch glass; marble.
Introduction
In this experiment we will become familiar with several instruments. Every instrument has some level of uncertainty, in other words, no measuring devise is perfect or exact. The smaller the increments of the measuring device, that is, the smaller the spaces between the actual markings (lines, tick marks) on the device, the closer the observer is able to determine the quantity being measured to its true value. The procedure used to report non-digital instrument readings is as follows: 1. Determine the size of the increments (spaces) on the measuring device (For example, 0.1cm, or 1mL). 2. Record your reading as a numerical value including one decimal place further to the right of the incremental value (For example, if the increment is 0.1cm, a one-tenth increment, you must record your reading as a numerical value that includes a digit or zero in the hundredths place). Examples of how to read non-digital volumetric, temperature, and length measuring instruments are provided below. For a digital measurement, record all the digits and zeros displayed. The number of significant figures in your measurement is based off of the accuracy of the instrument. The more significant figures, the more accurate the measurement is.
Mass (weight) measurements in this lab are recorded to the 0.01g (hundredth of a gram) or 0.001g (thousandth of a gram), depending on the precision of the digital balance used.
Volumetric measurements in this lab are made in graduated cylinders. Most of liquids we use are water (aqueous) solutions. The curved surface (curve “pointing” downward) that you observe when reading the volume contained in a graduated cylinder is called the meniscus. Observe the meniscus at eye level to read the volume correctly. In the 10mL graduated cylinder, the increments (spaces) are 0.1mL. In the 100mL graduated cylinder, the increments are 1mL. An example reading technique is shown in Figure 2-1.
Figure 2-1
Temperature measurements in this lab are recorded using a thermometer with increments of 1oC. Example temperature readings are shown in Figure 2-2.
Figure 2-2
Length measurements in this lab are recorded using printed metric rulers (below) with different size increments. On Ruler A, (Figure 2-3) the increments are 1cm. On Ruler B, (Figure 2-3) the increments are 0.1cm. On Ruler A, an example length might be estimated as 12.5cm. However, on Ruler B, the same example length might be estimated as 12.55cm because Ruler B has smaller increments.
Figure 2-3
Density
One distinguishing physical property of matter is density. Each pure substance has its own density. Therefore, density can be used to help identify the substance. In words, density is the ratio of a substance’s mass to the volume occupied by that mass. Mathematically, with density, d, mass, m, and volume, V,
d = _m_
V
In this lab, you will measure mass in grams, g, and volume in milliliters, mL. Therefore, the units of density will be, in words, grams per milliliter, or in symbols, g/mL or _g_ .
mL
Liquid volumes are easily measured by means of graduated cylinders. However, solids, unless precisely machined, for example, have volumes that are difficult to determine by direct measurement with a ruler or other similar instrument. The volume of irregularly shaped solids that do not dissolve (for example, rocks, pieces of metal) may be measured by the volume of a liquid that the solid displaces when the solid is completely submerged. If a graduated cylinder is partially filled with water and an insoluble solid is carefully submerged in the water, the water level will rise. The volume of the solid is the difference between the water levels before and after the solid is added.
In this lab, you will determine the density of water and the density of a metal slug.
Procedure
Part A: Measuring Length
- Measure the diameter of a watch glass using Ruler A (Figure 2-3).
- Record the measurement on your report.
- Measure the diameter of the same watch glass using
- Ruler B (Figure 2-3). Record the measurement on your report.
Part B: Measuring Mass
Digital balances are sensitive. Proceed carefully. Be sure the balance is energized. The display should read “0.00 g.” If it does not, press the “TARE” key (the one with T/0) and wait a few seconds. Place the item to be weighed on the balance pan and read the digital display. The digital display represents the mass of the item in grams. Remember that all the decimal places shown on the display are to be recorded.
- Use a digital balance to determine the mass of a 100mL beaker.
- Record the mass.
- Using a 100mL graduated cylinder, pour about 20mL of tap water into the same beaker. (See NOTE at the end of this paragraph.)
- Determine the combined mass of the beaker and water.
- Record the combined mass.
- Calculate the mass of the water. Record the result.
**(NOTE: When you read an instruction about a volume that states “about” or “approximately,” there is no need to go through the careful procedure described in the introduction to this lab. Unless your instructor tells you otherwise, use the “plus or minus 10%” rule. For example, for “about 20mL of tap water,” obtain between 18mL and 22mL of tap water.)
Part C: Measuring Volume
- Pour 1 Teaspoon of water in the 10 mL graduated cylinder.
- Record the volume of the water in the 10 mL cylinder.
- Pour 1/3 cup of water in the 100 mL graduated cylinder.
- Record the volume of the water in the 100 mL cylinder.
Part D: Measuring Temperature
- Fill a 250mL beaker about halfway with tap water.
- Use a thermometer to record the temperature.
- Using a microwave proof glass (such as a coffee mug), heat 1 cup of water to boiling.
- Carefully remove the water from the microwave and use a thermometer to record the temperature of the water.
Part E: Measuring the Density of a Liquid
- Dry a 10mL graduated cylinder, weigh it, and record its mass.
- Put about 9mL of deionized water into the cylinder and carefully record the volume of the water. (Refer to the introduction.)
- Weigh the cylinder with the water and record the combined mass.
- Calculate the mass of the water.
- Calculate the density of the water.
Part F: Measuring the Density of a Solid
- Weigh the marble and record its mass.
- Fill a 100mL graduated cylinder about halfway with tap water.
- Read and record this initial volume of water following the rules.
- Tilting the graduated cylinder at an angle without spilling the water, carefully slide the marble down the cylinder without splashing water up along the sides.
- Read and record this final volume of water.
- Calculate the volume of the marble and its density and record both values on your report.
Name__________________________
Section_______Date______________
Report for Experiment 2 Instructor_______________________
Measurements
Part A: Measuring Length
Diameter of watch glass using Ruler A __________________________
Diameter of watch glass using Ruler B __________________________
Part B: Measuring Mass
Mass of 100mL beaker __________________________
Mass of 100mL beaker with water __________________________
Mass of water __________________________
(show calculation)
Part C: Measuring Volume
Volume of water in 10mL cylinder __________________________
Volume of water in 100mL cylinder __________________________
Part D: Measuring Temperature
Temperature of cold water __________________________
Temperature of boiling water __________________________
Part E: Measuring the Density of a Liquid
Mass of cylinder __________________________
Mass of cylinder with water __________________________
Mass of water __________________________
(show calculation)
Volume of water __________________________
Density of water __________________________
(show calculation)
Part F: Measuring the Density of a Solid
Mass of marble _________________________
Initial volume of water __________________________
Final volume of water __________________________
Volume of marble __________________________
(show calculation)
Density of marble __________________________
(show calculation)
POST LAB QUESTIONS
- Determine the number of significant figures in each of the following measurements:
- 35s ___________ 1.05cm __________
- 89g ___________ f. 10.5mL __________
- 012g ___________ g. 10.00mL __________
- 0cm ___________ h. -40.0oC __________
- Perform the following calculations; apply sig. fig. and round off rules:
- 6g + 50.05g + 50.432g =
- 77mL – 23.4mL =
- (41.5cm)(0.4cm) =
- 8 mm3 / 25.4 mm =
- Convert 37.6oC to Fahrenheit. (Remember: In the formula for converting between Fahrenheit and Celsius, the “32” and “1.8” are exact numbers.)
- Convert 112oF to Celsius.
- What is the mass of a liquid that has a volume of 50.0mL and a density of 2.40g/mL?
- Calculate the volume, in milliliters, of a solid that has a density of 7.142g/cm3 and a mass of 232.51g. (HINT: 1cm3 = 1mL exactly)
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Genes of Genesis Solution
$10.00Week 1 | Discussion – The Origin of Life
Respond And Discuss
One of the theories of how life originated is that organic molecules came together in the ocean and life was created. There is a fascinating article regarding this on the website amazingdiscoveries.org(opens in a new window). Please download Genes of Genesis [DOWNLOAD] and read from “Molecules that Begin Life” through “Enzymes and Nucleic Acid Formation” and respond to the following prompts:
- Explore this topic in more detail and summarize how specifically a living molecule was supposed to have formed from an organic substance.
- According to the Bible, life started when God spoke it into existence. What flaws do you see with the theory that life came from organic compounds?
- The article cites several different types of organic molecules that were to have formed in early earth. Pick one molecule and describe how scientists theorize it formed. What are the inaccuracies with their method?
- With respect to the article, what evidence is there to support creationism? Find an outside source other than Wikipedia that will support this evidence.
Post your answers below and respond to at least two classmates’ posts with substantive responses.
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Cabbage Juice pH Indicator Solutions
$23.00Acids and Bases: Cabbage Juice pH Indicator
Introduction:
Liquids all around us have either acidic or basic (alkaline) properties. For example, acids taste sour; while, bases taste bitter and feel slippery. However, both strong acids and strong bases can be very dangerous and burn your skin, so it is important to be very careful when using such chemicals. In order to measure how acidic or basic a liquid is one must use the pH scale as illustrated below:
http://www.pullouttheplug.co.uk/…/ ph-scale.gif
In this lab, students will use the juice from red cabbage as a pH indicator to test common household liquids and determine their pH levels. You will mix cabbage juice with different household liquids and see a color change produced by a pigment called flavin (an anthocyanin) in red cabbage. Through this color change, you will be able to successfully identify the approximate pH of common household liquids using the table below:
Strength increases at extremes of this scale.
Cutting the cabbage:
- Cut ¼ of a cabbage into thin strips like shown below:
- Place the cut cabbage into a Ziploc bag. Note: Keep the red cabbage refrigerated.
Materials:
- Pre-cut cabbage
- Blender
- Strainer
- Large container
- 1liter beaker
- 7 plastic cups
- 7 plastic spoons
- Lemon soda
- White vinegar
- Apple juice
- Baking soda
- Shampoo (preferably clear)
- Conditioner (preferably clear)
- Hand sanitizer
Pre-Lab Questions
Look at each of the liquids being tested. Predict whether each of the substances is acidic, neutral or basic. Circle one. (Think about the properties of acids and bases.)
Part 1: Preparing the Cabbage Juice
Preparing the Cabbage Juice:
- Put the red cabbage leaves into the blender with 800mL of water.
- Close the top and let it blend at high power for 30 seconds.
- Once it is blended, filter out the leaves inside the mixture with the strainer and pour the mixture into a large container.
*This should provide you with 600-800 ml of cabbage juice.
Part 2: Mixing the Cabbage Juice
- Label each cup with each of the liquids. (Example: vinegar, apple juice, etc.)
- Pour 100 ml of each individual liquid into its respective cup (except for baking soda).
- For baking soda, add 3 tablespoons of baking soda into 100 ml water.
Example:
- Pour 50 ml of cabbage juice into each of the cups. Do this one at a time and record the color change below:
Now look up the actual pH of each of the substances and see how accurate the cabbage juice indicator was!
How did your reasoning for your predictions change after seeing the approximate pH level?
Does the color intensity of the liquid change? If so, how and why do you think this is?
Concept Questions:
- Does the addition of water (baking soda + water) alter the pH of weak acids/bases? How does it change the pH of strong acids/bases? Why or why not?
- How does a difference in 1 pH unit change in terms of H+ concentration? Example: How does a pH of 3 differ from pH of 4? Which one is stronger or weaker? Why?
- Look at the ingredients for each liquid you tested. Which ingredients contribute to each of the liquid’s pH level?
Real Life Applications:
- Neutralization: Whenever you mix an acid with a base, they neutralize each other. If this is the case, why is Alka-Seltzer used to treat stomach aches? (Note: excess stomach acids cause stomach aches)
- What is acid rain and how does it negatively impact oceans, rivers, lakes, and other natural environments?
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Nursing and the budget
$5.00Assignment 1: Discussion Assignment
All health care organizations have complicated budgeting policies and procedures. The more the nurse understands the process, the more effectively they can participate in the process. The budget process usually starts with an interdisciplinary approach.
Describe the potential members of the interdisciplinary team for budget development and the role of each individual.
What are the specific responsibilities of nursing in the development of the budget?
Are the responsibilities for budget specific only to the leadership of the nursing department or are they found throughout the organization? -
Most health problems
$5.00Assignment 1: Discussion Assignment
The discussion assignment provides a forum for discussing relevant topics for this week based on the course competencies covered.
Health Problems
Which area, rural or urban, has the most health problems? Why? Justify your response based on the readings or articles from the South University Online Library.To support your work, use your course and text readings and also use the South University Online Library. As in all assignments, cite your sources in your work and provide references for the citations in APA format.
Start reviewing and responding to the postings of your classmates as early in the week as possible. Respond to at least two of your classmates. Participate in the discussion by asking a question, providing a statement of clarification, providing a point of view with a rationale, challenging an aspect of the discussion, or indicating a relationship between two or more lines of reasoning in the discussion. Cite sources in your responses to other classmates. -
U.S. government obligations to its citizens
$5.00Prepare: Prior to beginning work on this discussion, read chapters 8, 9, and 10 in American Government and review Week Four Instructor Guidance.
Write Icon
Write: In your initial post, explain what obligations the U.S. government has towards its citizens and how can these obligations impact individual and group rights? Provide real-world examples to support your explanation. Fully respond to all parts of the prompt and write your response in your own words.Fully respond to all parts of the prompt and write your response in your own words. Your initial must be at least 300 words. Support your position with at least two of the assigned resources required for this discussion, and/or peer reviewed scholarly sources obtained through the AU Library databases. Include APA in-text citations (Links to an external site.)Links to an external site. in the body of your post and full references on the references list (Links to an external site.)Links to an external site. at the end. Support your position with information from two or more of the assigned resources required for this discussion. Please be sure that you demonstrate understanding of these resources, integrate them into your argument, and cite them properly.
Reflect Icon
Reflect: Our political system is characterized by certain fundamental features to include a system of laws, rights, and liberties. The laws, created and supported by the Constitutional framework, are designed to protect and secure the rights and liberties of individuals and groups throughout the U.S. However, the government also has an obligation to provide for the security of its citizens from serious internal and external threats that could cause grave or severe damage to our country. Think about how the need for homeland and national security can create a dilemma where conflicts emerge between these security needs and the demands for civil rights and liberties.Discuss Icon
Respond to Peers: By Day 7, respond to at least two of your classmates’ initial posts. Your peer responses should be substantive and at least 100 words each. As your reply to your classmates, attempt to take the conversation further by examining their claims or arguments in more depth or responding to the posts that they make to you. Keep the discussion on target and try to analyze things in as much detail as you can. For instance, you might consider if your classmate’s arguments are well supported with valid sources and logically argued. -
Advocacy strategies to create change in workplace
$5.00Advocacy strategies to create change in workplace
Identify advocacy strategies that you can use to create change in your current workplace.
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Educational preparation of the clinical nurse leader (CNL)
$5.00Educational preparation of the clinical nurse leader (CNL)
Identify the educational preparation and role(s) of the clinical nurse leader (CNL) designation. Give an example of how the CNL influences direct patient care whether in a hospital or out in the community.
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Aggregate Description
$15.00Assignment 2: Dropbox Assignment
Capstone Project: Phase 2: Describing the AggregateIn Phase 2 of the project, research and describe the demographics and statistics of your aggregate. Include information about the basic vital statistics of the aggregate such as the crude birth rate, infant mortality rate, life expectancy, the leading causes of death, and any other relevant statistical information related to the health of the aggregate. In addition, explain how the local clinic meets, supports, and advocates for evidence-based practice (EBP). As a part of this assignment, you will need to create a questionnaire and interview at least one healthcare provider who is familiar with your selected aggregate.
Tips
One of the most effective ways to obtain this information is to interview people who are familiar with and have worked with the selected aggregate, such as biostatisticians or other social and healthcare providers of the aggregate.
A well-planned questionnaire with carefully developed questions can help you elicit adequate and relevant information from the interviewees.
Your response should be in the form of a 2- to 3-page Microsoft Word document. Use relevant charts and graphs to support the information you collected. Identify the sources of your information and describe how you went about collecting the information.
Cite all sources in APA format.Assignment 2 Grading Criteria
Maximum Points
Selected and described an aggregate.
12
Utilized and explained MAP-IT in the assessment process.
8
Explained how the local clinic meets, supports, and advocates for EBP.
8
Included demographic and statistical information of the selected aggregate.
12
Presented information obtained from interview of people who are familiar with the selected aggregate.
8
Developed a well-planned questionnaire for obtaining information from interviewee pertaining to the aggregate.
8
Cited at least two journal articles as references for ideas in your work.
4
Written components.
20
Total:
80