Module 2 Chem 22 Knewton Alta

One year consists of 365 days. This is closest to how many seconds? (Remember the following conversion factors: kilo (10^3), mega (10^6), giga (10^9), and tera 10^12.)

31.5 mega seconds

What is 32.492 rounded to three significant figures?

32.5 The fourth digit is a 9, which means the 4 will round up to 5, giving 32.5 as our final value.

If we wish to convert a value in years into days, a conversion factor we could use would be:

365 days/1 year

Use dimensional analysis to convert 15.0 inches into centimeters. (1.00 in =2.54 cm) 2.54 cm 5.09 cm 38.1 cm 40.3 cm

38.1 cm To convert between inches and centimeters you use the conversion factor: 1.00 in = 2.54 cm. 15.0 in × 2.54 cm/1.00 in = 38.1 cm

An LCD TV was put in a box of size 12×24×24 inches. What is the volume of the box in cubic feet?

4 ft^3

The distance between two towns is 40,000 meters. Write this value in scientific notation

4.0 x 10^4 m Because the magnitude of this number is greater than 1, the exponent will be positive. Move the decimal point to the left until the number has a single digit in the ones place. In this case, the decimal point is moved 4 places to the left to get the number 4, and this means the exponent is 4. Therefore, 40,000=4×104

A student drops a 5.00 kg block into a tank containing 100.00 L of water. The block sinks to the bottom of the tank and the water level rises to 101.25 L. What is the density of the block? The density of the block is 0.05 kg/L. The density of the block is 4.00 kg/L. The density of the block is 0.049 kg/L. The density of the block is 20.25 kg/L

4.00 The water level rose from 100.00L to 101.25L. This means it displaced 1.25L water, an amount equal to the volume of the block. The mass is given as 5.00kg. With these two values, mass and volume, we can now use our density equation (see below) to calculate the density of the block. 5.00 kg/1.25 L= 4.00 kg/L

The density of titanium is 4506 kg per cubic meter. What is the density of titanium in grams per cubic centimeter? Do not include units in your answer.

4.506 g/cm^3

Complete this calculation to the correct number of significant figures: 2.33×18

42 When multiplying or dividing, round your answer so it has the same number of significant figures as the value with the least number of significant figures.

How many hours are there in exactly 180 days?

4320

A football field is supposed to be exactly 120 yd long, including the end zones. How many inches is this? (1 yd = 3 ft, 1 ft = 12 in.)

4320 in

A rectangular painting has an area of 2890 square centimeters. What is its area in square inches? Round to the nearest square inch. Do not include the units in your answer.

448

Why does a measurement of specific gravity not have a unit? Because it is not a true measurement Because the units cancel out in the calculation Because specific gravity is not a derived quantity Because you can easily look up the value on a table

Because the units cancel out in the calculation

Select which of the following is NOT a rule for rounding numbers when considering significant figures. For addition and subtraction, round the result to the same number of decimal places as the number with the least number of decimal places. For multiplication and division, round the result to the same number of digits as the number with the most number of significant figures. Round down if the digit to be dropped is less than Round up if the digit to be dropped is more than

For multiplication and division, round the result to the same number of digits as the number with the most number of significant figures. All of these are rules for rounding significant figures except for the second option. The result should be rounded to the same number of digits as the number with the LEAST number of significant figures.

Which of the following is NOT needed to calculate specific gravity?

Gravity

Which of the following best describes specific gravity? It is a derived quantity. It is a measured quantity. It is a comparative quantity. It is not a useful quantity.

It is a comparative quantity.

Which of the following is a rule of significant figures in calculations? Round the result to the same number of digits as the number with the most number of significant figures. Round up if the digit to be dropped is less than 5. Round down if the digit to be dropped is less than 5. None of the above

Round down if the digit to be dropped is less than 5 We round down if the digit to be dropped is less than 5. For example, to round the value 2.443 to three significant figures, we round down to 2.44 because the digit to be dropped (3) is less than five

Which of the following is a rule for determining significant figures in calculations involving addition and subtraction? Round the result to the same number of digits as the starting term with the most significant figures. Round up if the digit to be dropped is less than Round down if the digit to be dropped is more than Round the result to the same number of decimal places as the starting term with the lowest number of decimal places.

Round the result to the same number of decimal places as the starting term with the lowest number of decimal places. When performing addition and subtraction calculations, the starting term with the lowest number of decimal places indicates the number of decimal places to which the result should be rounded. In addition, the result should be rounded down if the digit to be dropped is less than 5 and rounded up if the digit to be dropped is 5 or greater.

The oil settles on the surface of the water after an oil spill because:

oil is less dense than water

Jordan measures a cube and finds that each side (length, width, height) of the cube is 3.0cm. She then uses a scale and finds the mass of the block is 243g. What is the density of the block? Of what substance is the block made? The density is about 1.0g/cm^3, and the block is oak (wood). The density is about 10.0g/cm^3, and the block is silver. The density is 9.0g/cm^3, and the block is copper. The density is about 9.0g/cm^3, and the block is iron.

The density is 9.0 g/cm^3, and the block is copper.

What does a specific gravity of 1 indicate? Select the correct answer below: The sample is very light The sample is less dense than the reference The sample is more dense than the reference The sample and the reference are the same density

The sample and the reference are the same density In order for the specific gravity to be equal to 1, the ratio of the density of the sample substance to the density of the reference substance must be 1 and therefore the sample and the reference must be the same density. In this case, the actual density of each substance is not important, as it is the ratio between the two substances that gives the dimensionless value of specific gravity.

What is the criteria for a substance to be used as a reference for determining specific gravity of a substance? The substance is a fluid substance The substance is a gaseous substance The substance has a density of 1.0 g/mL The substance is defined beforehand

The substance is defined beforehand

Saltwater covers approximately 361,900,000 square kilometers of the earth's surface. Write the number of square kilometers of saltwater in scientific notation.

3.619 × 108 square kilometers

Why is specific gravity a dimensionless quantity? It has no units. It is only used in special circumstances. It is a directional value. none of the above

it has no units

What is the volume in liters of 1.00 oz, given that 1 L=1.0567 qt and 1 qt=32 oz (exactly)? 0.9463 L 0.0333 L 0.0312 L 0.0296 L

0.0296 L First you have to convert ounces to quarts using the conversion factor 1 qt=32 oz. This yields the answer 0.03125 qt, the volume in quarts. 1.00 oz×1 qt32 oz=0.03125 qt Then you need to convert this volume to liters using the unit conversion 1 L=1.0567 qt. 0.03125 qt×1 L1.0567 qt≈0.029573 L Rounding to three significant figures, the result is 0.0296 L

What is 498 mm in m? Select the correct answer below: 498 m 49.8 m 4.98 m 0.498 m

0.498 m Multiplying the original value by the conversion factor 1 m/1000 mm gives us a value of 0.498 m.

What is the specific gravity of a substance that weighs 75 g and occupies a volume of 150 mL? 0.5 0.25 1 0.05

0.5

The temperature of a substance changes by 1K. This is equal to a temperature change of ________?

1 C

A chemical container measures 1 ft×1 ft×12 in. Calculate the volume of the container in cubic feet. 12 ft^3 3 ft^3 1 ft^3 144 ft^3

1 ft^3 First, convert the last dimension from inches to feet: 12 in. × 1 ft/12 in. = 1 ft Then, multiply to find the volume of the container: 1 ft × 1 ft × 1 ft = 1 ft^3

To convert cubic meters into cubic kilometers, one would multiply by __________. Select the correct answer below: (1km/1000m) (1000m/1km) (1km/1000m)3 (1000m/1km)3

(1km/1000m)3 We are converting from meters to kilometers, so meters must be in the denominator in our conversion factor, and because it's a cubic unit, the conversion factor must also be cubed.

The speed of light is around 6.706×10^8 miles per hour. What is the speed of light in units of miles per minute?

1.118 × 10^7 miles per minute To find the speed of light in units of miles per minute, we must use the fact that 60 min = 1 hr. 6.706 × 108 mi/hr× 1 hr/60 min = 1.118× 107 mi/min Therefore, we find that the speed of light is approximately 1.118 × 10^7 miles per minute

A light-year is a measure of distance rather than time; it is the distance that a ray of light will travel in a year in a vacuum. The distance between the earth and the sun is approximately 0.0000158 light-years. Write this number in scientific notation.

1.58 × 10^-5 To convert a number written in standard notation with a value less than 1 into scientific notation, move the decimal point to the right until the number has a single digit to the left of the decimal point. Then multiply the result by 10 raised to the negative power of the number of places that the decimal point was moved. In this case, the decimal point in 0.0000158 must be moved to the right 5 places to write the number as 1.58, so 1.58 is multiplied by 10−5. One way to think of this is that moving the decimal place to the right makes the number larger by a factor of 10 to the number of decimal places moved, so the number must be multiplied by a factor of 10 to the negative number of decimal places moved in order for it to retain the same value.

What is 50 °F in Celsius?

10 celsius To convert Fahrenheit into Celsius you need to use the equation: C = 5/9 (F − 32) Plug in the numbers given and you get: C = 5/9 (50−32) = 90/9 = 10

The engineer's model of a sugar factory has a floor area of 30 inches by 52 inches. The floor area of the model is __________ square feet Select the correct answer below: 13.74 10.8 130 1560

10.8 This can be calculated by multiplying the dimensions of the model in inches and then converting into square feet, being sure to square the inch-to-feet conversion factor. 30 in. × 52 in. × (1 ft12 in.)^2 = 10.8 ft^2

A speed limit in a U.S. city is 65.0 miles per hour. Canadian cities express speed limits in kilometers per hour. Express the value in km/hr. (1.609 km = 1 mile)

105 km/hr

A small snail makes a journey that takes him in a circle of area 0.750 square meters in one day. What is the area of the circle that the snail makes in square inches? Round to three significant figures. Do not give the units in your answer. Use the conversion factor 1 inch = 2.54 centimeters

1160 in^2 Convert square meters to square centimeters, and then to square inches. Use the squared conversion factor in each case. There are 100 centimeters in a meter and 2.54 centimeters in an inch. Multiply 0.750 m^2 by (100 cm/m)^2 and then by (1 in/2.54 cm)^2. Note that the conversion factors must be squared because square meters are converted to square centimeters and then square centimeters are converted to square inches. 0.750 m^2 × (100 cm/m)^2 × (1 in./2.54 cm)^2 = 1,160 in.^2

The bed of a large pickup truck has a carrying capacity of 2.5 cubic yards. How much is the capacity in cubic inches? Use the conversion factor 1 yard =36 inches

116640 To convert cubic yards to cubic inches, use the cubed conversion factor. There are 3 feet in a yard and 12 inches in a foot, so 1 yard = 36 inches. Multiply 2.5 yd^3 by (36 in./yd)^3. 2.5 yd^3 × (36 in./yd)^3 = 116,640 in.^3

Mercury has a density of 13.56 g per cubic centimeter. Convert the density to kilograms per cubic meter. Select the correct answer below: 13,560 kg/m3 135.6 kg/m3 1.356 kg/m3 0.01356 kg/m3

13,560 kg/m3 This problem requires using two different conversions: grams to kilograms and centimeters to meters. Since the starting units have grams in the numerator, use the conversion factor 1 kg/1000 g to obtain kilograms in the numerator. The starting units have cubic centimeters in the denominator, so use the cubed conversion factor (100 cm/1 m)^3 to obtain cubic meters in the denominator. 13.56 g/cm^3 × 1 kg/1000 g × (100 cm/1 m)^3 = 13560 kg/m3

The moon is 384,400 km from earth. Select the value that corresponds to this distance expressed in scientific notation. Select the correct answer below: 384,400 km 3844×100 km 384.400×103 km 3.844×105 km

3.844×105 km The magnitude of this number is greater than 1, so the exponent will be positive. Move the decimal point to the left until the number has a single digit in the ones place. In this case, the decimal point is moved 5 places to the left.

Two cubes sit side-by-side. The side length of the larger cube is 2.50 times the side length of the smaller cube. How many times larger is the volume of the larger cube than the volume of the smaller cube? Round to three significant figures.

15.6 times large The side length of the larger cube is 2.5 times that of the smaller. Since the volume of a cube is equal to the side length cubed, the volumes will be related by a factor of (2.5)3. (2.5)3= 15.625 which, rounded to three significant figures, is 15.6. The volume of the larger cube is about 15.6 times the volume of the smaller cube.

A rug has an area of 2,370 square inches. What is its area in square centimeters?

15300

A rectangular tank measures 12 in.×12 in.×24 in. Calculate the volume of the tank in cubic feet.

2 ft ^3

In the process of vision, the light-sensitive pigment rhodopsin undergoes cis-trans isomerism in response to light in about 2×10−10ms. How many seconds is this? Write the answer in scientific notation.

2 x 10^-13 s Note that the prefix m stands for "milli." A millisecond equals 1×10−3 second. Use this to write 2 × 10 − 10 ms in seconds. 2 × 10^−10 ms × 10^−3 s ms = 2 × 10^−13s 2×10^−10 ms equals 2×10^−13 seconds.

A tiny gas bubble in a carbonated beverage contains 2.69×1012 carbon dioxide molecules. Write the number of molecules in standard notation. 2,690,000,000,000 0.00000000000269 269,000,000,000,000 269,000,000,000

2,690,000,000,000 The exponent, 12, is positive, so move the decimal point to the right 12 times, adding 0s as needed to find the value. Therefore, 2.69×1012=2,690,000,000,000.

The label on a soft drink bottle gives the volume in two units: 2.0 L and 67.6 fl oz. Use this information to derive a conversion factor between the English and metric units. Select the correct answer below: 2.0 L67.6 fl. oz.=0.030 L1 fl. oz. 67.6 fl. oz.2.0 L=0.030 L1 fl. oz. 1 fl. oz.2.0 L=0.030 L1 fl. oz. 1 fl. oz.2.0 L=0.030 L67.6 fl. oz.

2.0 L67.6 fl. oz.=0.030 L1 fl. oz. For this question, we must set up a ratio to figure out the number of liters in one fluid ounce. We do this by noting that there are 2.0 L in 67.6 fl. oz.: we set this up as 2.0 L67.6 fl. oz.. To figure out the number of liters in one fluid ounce, we simply divide 2.0 L by 67.6 fl. oz. This gives us 0.030 L1 fl. oz.. Completing the ratio, we obtain 2.0 L67.6 fl. oz.= 0.030 L1 fl. oz.

A cube with a mass of 250.0 g has sides measuring 5.00 cm each. What is the density of this cube in grams per cubic centimeter?

2.00 g/cm^3

If 1 in.= 2.54 cm, calculate the number of inches in 75.0 cm

29.5 in

What is 0.29 km in mm? Select the correct answer below: 2.9 mm 290 mm 29,000 mm 290,000 mm

290,000 mm

Solve the following problem and report answers with appropriate number of significant digits: 1.31 cm×2.3 cm= _____ 3.0 cm .99 cm 3 cm 2.6 cm

3.0 cm

Complete the following calculation and report your answer using the correct number of significant figures: 5.4589−2.33

3.13 When adding and subtracting, round your answer so it has the same number of decimal places as the value with the least number of decimal places.

The wavelength of yellow light is approximately 0.000000580m. Convert this quantity from meters to nanometers.

5.80 x 10^2 nm The prefix "nano" means 10−9. To convert meters to nanometers, move the decimal point to the right 9 times, filling in zeros as needed, and then use a prefix symbol, n, to represent 10−9. 0.000000580m=580×10−9m=580nm Now, to write 580nm in scientific notation, move the decimal so that there is only one nonzero digit to the left of the decimal place. Therefore, the decimal should be moved two places to the left. The exponent on 10 will be equal to the number of places the decimal is moved. Therefore, the value written in scientific notation is as follows. 580nm=5.80×102nm Recall that if a trailing zero is on the right side of a decimal point, it is significant and should be included in the scientific notation.

A cylinder has a volume of 3 cubic feet. What is the volume in cubic inches?

5184 in^3

What is 198 g + 334.6 g, rounded to the proper number of significant figures?

533 g

A block of ice measures 2 ft×1 ft×2 in. Find the volume of the ice block in cubic inches 6912 in.^3 48 in.^3 576 in.^3 4 in.^3

576 in.^3

A meteorite was found to weigh 63,500 grams. How many kilograms is this?

63.5 kg The prefix "kilo" means 103, so 1kg = 1 × 103g. To convert grams to kilograms, move the decimal point to the left 3 places and then use the prefix symbol, k, to represent 103. 63,500g=63.5×103g =63.5kg

The density of a particular steel alloy is 8050 kg per cubic meter. Convert the density to grams per cubic centimeter.

8.050 g/cm^3 8050 kg/m^3 × 1000 g/1 kg ×(1 m/100 cm)^3 = 8.050 g/cm^3

How many significant figures does the number, 2098.00703 contain? 5 9 4 2

9 all zeroes are captured in between non zero digits

Which of the following must be true about a precise measurement? It typically contains many significant figures. It has very few significant figures. It is very close to the true value. It is far away from the true value.

It typically contains many significant figures. A precise measurement has a high degree of certainty, as indicated by having many significant figures.

In which temperature scale is the boiling point of water represented by the largest number? Celsius Fahrenheit Kelvin The number stays the same in all units.

Kelvin The boiling point of water is 100 Celsius, 212 Fahrenheit, and 373 Kelvin. Therefore the boiling point of water is represented by the largest number on the Kelvin scale.

What would happen to the block if it had a density of 0.500 kg/L and was placed in the same 100.0 L tank of water? It would sink. It would float. It would initially sink and then rest in the middle of the tank. There is not enough information to answer this question

it would float

In addition to the density of the object, what other measurement do you need to need to know to calculate the specific gravity of the object? density of a reference substance volume of the substance mass of the substance none of the above

density of a reference substance

Which would NOT be an appropriate unit for density?

g/s

If object A and object B have the same density, but object A has greater mass, then object A must have: greater volume smaller volume the same volume can't be determined

greater volume

The number of significant figures in a value is a display of the _________ of a measurement.

precision Accuracy is a measure of how close a measurement is to a true or accepted value, whereas precision is a measure of how well consecutive measures of the same quantity agree with one another. The number of significant figures in a value will provide information regarding the precision of the value. For example, 15.000mL is a more precise value than 15mL. Significant figures alone will not provide evidence to suggest that a measured value is close to the true or accepted value.

In dimensional analysis, what is a conversion factor?

ratios of physical quantities used to compare desired units

What is the reference substance used to calculate the specific gravity of most liquids? The mass of the liquid. The volume of the liquid. The density of water. The density of air.

the density of water

For a number written in scientific notation, 1.02×10−7, what does the exponent represent? the amount of zeros to add to the digit term how many times to multiply the digit term by itself the power of ten the digit term is multiplied by reliability of the digit term to the accepted value

the power of ten the digit term is multiplied by In scientific notation, the digit term (also known as the mantissa) is the number before the times symbol, and it gives the precise value of the number. The exponent (b) gives the order of magnitude of the number (power of 10) and can be used to count the number of decimal shifts from the mantissa to write the number in standard notation.

Which of the following temperatures are equivalent to absolute zero (0 K)? 74.93∘F −100∘C −273.15∘C −459.67∘F

−273.15∘C and −459.67∘F