chemi

· Here are four sketches of pure substances. Each sketch is drawn as if a sample of the substance were under a microscope so powerful that individual atoms could be seen.

· Decide whether each sketch shows a pure sample of an  element or a pure sample of a  compound.

Substance A Substance B element element compound compound Substance C Substance D element element compound compound

·

· The safe dosage of the IV antibiotic ceftriaxone for children weighing more than 

· 2.0kg

·  is 

· 60.mg

·  per kilogram of body weight. Suppose a pediatric nurse has available 

· 1.5L

·  of a ceftriaxone solution with a concentration of 

· 0.040/gmL

· . How can she calculate the volume of this solution that she should administer to a child weighing 

· 39.kg

· ?

· Set the math up. But don't  do any of it. Just leave your answer as a math expression.

· Also, be sure your answer includes all the correct unit symbols.

solution=needed · Substance A: Compound (different types of atoms bonded together) · Substance B: Element (only one type of atom) · Substance C: Compound (different types of atoms bonded together) · Substance D: Element (only one type of atom)

Decide whether each proposed addition or subtraction of measurements is possible. If it  is possible, write the result in the last column of the table. Be sure every answer you enter has the correct unit symbol.

Rewrite this measurement with a simpler unit, if possible.

4.3·gcm·cm2cm2

Note: If you can simplify the unit at all, it may be possible to make more than one simplification. Be sure your final answer uses the simplest possible unit.

Decide whether each proposed multiplication or division of measurements is possible. If it  is possible, write the result in the last column of the table.

Take a look at this sketch, and then answer the questions below about the mass, volume and density of Objects  B and  C.

A chemist working as a safety inspector finds an unmarked bottle in a lab cabinet. A note on the door of the cabinet says the cabinet is used to store bottles of tetrahydrofuran, dimethyl sulfoxide, methyl acetate, ethanolamine, and acetone.

The chemist plans to try to identify the unknown liquid by measuring the density and comparing to known densities. First, from her collection of Material Safety Data Sheets (MSDS), the chemist finds the following information:

Next, the chemist measures the volume of the unknown liquid as 1982.cm3

and the mass of the unknown liquid as 1.57kg.

A chemistry student needs 90.0g of diethylamine for an experiment. By consulting the  CRC Handbook of Chemistry and Physics, the student discovers that the density of diethylamine is 

·0.706gcm−3. Calculate the volume of diethylamine the student should pour out.

Be sure your answer has the correct number of significant digits. ______________mL.

Experiments were done on a certain pure substance  X to determine some of its properties. There's a description of each experiment in the table below.

In each case, decide whether the property measured was a chemical or physical property of  X, if you can. If you don't have enough information to decide, choose  can't decide in the third column.

Green Dragon Orchards makes and sells fancy apple cider in different size bottles. Decide whether each property of their apple cider bottles listed in the table below is extensive or intensive, if you can. If there's not enough information to decide, check the  can't decide box.

There are four sketches below. The first sketch shows a sample of Substance X. The three sketches underneath it show three different changes to the sample. You must decide whether each of these changes is possible. If a change is possible, you must also decide whether it is a physical change or a chemical change.

Each sketch is drawn as if the sample were under a microscope so powerful that individual atoms could be seen. Also, you should assume that you can see the entire sample, and that  the sample is in a sealed box, so that no matter can enter or leave.

Write −7.354 in scientific notation.

A chemist needs to know the mass of a sample of MgCl2 to 2 significant digits. She puts the sample on a digital scale. This is what the scale shows:

Add or subtract the following measurements. Be sure each answer you enter contains the correct number of significant digits.

Multiply or divide the following measurements. Be sure each answer you enter contains the correct number of significant digits.

A chemical engineer must report the average volume of a certain pollutant produced by the plants under her supervision. Here are the data she has been given by each plant:

What average volume should the chemical engineer report? Be sure your answer has the correct number of significant digits.

A chemistry student must write down in her lab notebook the concentration of a solution of potassium chloride. The concentration of a solution equals the mass of what's dissolved divided by the total volume of the solution.

Here's how the student prepared the solution:

· The label on the graduated cylinder says:

empty weight:  8.50g

· She put some solid potassium chloride into the graduated cylinder and weighed it. With the potassium chloride added, the cylinder weighed 15.989g.

· She added water to the graduated cylinder and dissolved the potassium chloride completely. Then she read the total volume of the solution from the markings on the graduated cylinder. The total volume of the solution was 179.1mL.

What concentration should the student write down in her lab notebook? Be sure your answer has the correct number of significant digits.

What is the voltage this voltmeter is measuring?

Be sure your answer has a reasonable number of decimal places.

Four research teams measured the half-life of a radioactive isotope, and what each team wrote in its team notebook is shown in the table below.

Suppose a later and more reliable measurement gives 0.480 s for the half-life of the same isotope. Decide which of the earlier measurements was the most accurate, and which was the most precise.

A student sets up the following equation to convert a measurement.

(The ? stands for a number the student is going to calculate.)

Fill in the missing part of this equation.

A student sets up the following equation to convert a measurement.

(The ? stands for a number the student is going to calculate.)

Fill in the missing part of this equation.

A student sets up the following equation to convert a measurement.

(The ? stands for a number the student is going to calculate.)

Fill in the missing part of this equation.

A student sets up the following equation to convert a measurement.

(The ? stands for a number the student is going to calculate.)

Fill in the missing part of this equation.

Note: your answer should be in the form of one or more fractions multiplied together.

Suppose you need 9.5m of Grade 70 tow chain, which has a diameter of /38" and weighs 

2.16/kgm, to tow a car. How would you calculate the mass of this much chain?

Set the math up. But don't  do any of it. Just leave your answer as a math expression.

Also, be sure your answer includes all the correct unit symbols.

The safe dosage of the IV antibiotic ceftriaxone for children weighing more than 2.0kg is 

60.mg per kilogram of body weight. Suppose a pediatric nurse has available 1.5L

 of a ceftriaxone solution with a concentration of 0.040/gmL. How can she calculate the volume of this solution that she should administer to a child weighing 39.kg?

Set the math up. But don't  do any of it. Just leave your answer as a math expression.

Also, be sure your answer includes all the correct unit symbols.

solution=needed

Cobb, C. (2015).  The project manager's guide to mastering agile. Hoboken, NJ: John Wiley & Sons, Inc.

Rubin, K. S. (2013).  Essential Scrum: A practical guide to the most popular Agile process. Addison-Wesley.

Schwaber, K., & Sutherland, J. (2017).  The Scrum Guide. Scrum.org.