Chemistry midterm

You go out to dinner and the bill comes to $ 47.05. How much should you tip if you want the tip to be 15.0 % of the bill? Express the dollar amount to the nearest cent.

$7.06

In a laboratory, you determine that the density of a certain solid is 5.23×10−6kg/mm3. Convert this density into kilograms per cubic meters. Notice that the units you are trying to eliminate are now in the denominator. The same principle from the previous parts applies: Pick the conversion factor so that the units cancel. The only change is that now the units you wish to cancel must appear in the numerator of the conversion factor. Express your answer in kilograms per cubic meter.

5230 kg/m3

Compute 6.28×1013+6.30×1011. Express your answer to three significant figures

6.34×1013

Compute (4.29×1015)⋅(1.64×10−4). Express your answer to three significant figures.

7.04×1011

Suppose that a certain fortunate person has a net worth of $76.0 billion ($7.60×1010). If her stock has a good year and gains $3.20 billion (3.20×109) in value, what is her new net worth? Express your answer to three significant figures.

7.92×1010 dollars

You have 125 g of a certain seasoning and are told that it contains 98.0 g of salt. What is the percentage of salt by mass in this seasoning? Express the percentage numerically. Do not round.

78.4% salt by mass

Below are two expressions, the only difference being the presence or absence of parentheses. expression 1:expression 2:5+2×(3+5)×(4−2)5+2×3+5×4−2 Calculate the difference between the two expressions; that is, evaluate both expressions then subtract one value from the other value. Express your answer numerically.

8

Calculate the result of the following set of operations: 2×1+32−6÷2 Express your answer numerically.

8

Type the number 8.75×10−4 in standard notation. Express your answer using standard notation.

8.75×10−4

Suppose that this individual now decides to give one-eighth of a percent (0.125 %) of her new net worth to charity. How many dollars are given to charity? Express your answer to three significant figures.

9.90×107 dollars

Calculate the value of 3/8÷13/12 Enter the numerator followed by the denominator, separated by a comma.

9/26

In a college of exactly 2980 students, exactly 45 % are male. What is the number of female students? Express your answer as an integer.

0 + 1i female students

Suppose that you measure a pen to be 10.5 cm long. Convert this to meters. Express your answer in meters.

0.105 m

Now, find the value of (3/16⋅2/5)/(7/4⋅3/2) Finding this value consists of simply multiplying twice and then dividing once, tasks that are no more difficult than what you've done before. Enter the numerator followed by the denominator, separated by a comma.

1,35

If you have a quarter of a pie and you cut it in half, what fraction of a pie would each slice represent? Enter the numerator followed by the denominator, separated by a comma.

1,8

Type the number 1340000 in scientific notation. Express your answer using scientific notation.

1.34×106

Suppose that you find in a reference book that the volume of all the oceans is 1.4×109km3. To find the mass, you can use the density of water, also found in this reference book, but first you must convert the volume to cubic meters. What is this volume in cubic meters? Express your answer in cubic meters.

1.40×1018 m3

Suppose that, from measurements in a microscope, you determine that a certain bacterium covers an area of 1.50μm2. Convert this to square meters. Express your answer in square meters.

1.50×10−12 m2

Consider the following equivalent expressions: 3/8÷13/12 and 3/8⋅a/b What are the values of a and b? Enter the value of a followed by the value of b, separated by a comma.

12,13

How many loads of laundry can you wash if you work 3 shifts? Express your answer numerically as an integer.

15 loads

Consider the following two expressions, the only difference being the presence or absence of parentheses. expression 1:expression 2:3x2(3x)2 Calculate the difference between the two expressions when x = 5; that is, evaluate both expressions then subtract one value from the other. Express your answer numerically.

150

Determine the number of significant figures in the measurement 0.0030 s. Express your answer numerically as an integer.

2

How many shifts must you work if you wish to wash 10 loads of laundry? Express your answer numerically as an integer.

2 shifts

Round the value 23.731 g to three significant figures. Express your answer numerically using three significant figures.

23.7 g

How many loads of laundry will each shift pay for if the cost per load rises to 8 quarters? Express your answer numerically as an integer.

3 loads

Type the number 0.000354 in scientific notation. Express your answer using scientific notation.

3.54×10−4

Type the number 3.14×103 in standard notation. Express your answer using standard notation.

3140

Find the value of 17/15⋅2/11 Though these numbers aren't quite as nice as the ones from the example or the previous part, the procedure is the same, so this is really no more difficult. Enter the numerator followed by the denominator, separated by a comma.

34,165

Determine the number of significant figures in the measurement 77.09 m. Express your answer numerically as an integer.

4