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Computing quantities from measurement results and known mathematical relations

While being driven from Philadelphia to Atlanta, a distance of about 1250 km, a 2014 Lamborghini Aventador Roadster uses 213 L gasoline.

(a) What (average) fuel economy, in miles per gallon, did the Roadster get during this trip?

(b) If gasoline costs $3.80 per gallon, what was the fuel cost for this trip?


(a) We first convert distance from kilometers to miles:

1250 km × 0.62137 mi 1 km = 777 mi

and then convert volume from liters to gallons:

213 L × 1.0567 qt 1 L × 1 gal 4 qt = 56.3 gal


(average) mileage = 777 mi 56.3 gal = 13.8 miles/gallon = 13.8 mpg

Alternatively, the calculation could be set up in a way that uses all the conversion factors sequentially, as follows:

1250 km 213 L × 0.62137 mi 1 km × 1 L 1.0567 qt × 4 qt 1 gal = 13.8 mpg

(b) Using the previously calculated volume in gallons, we find:

56.3 gal × $3.80 1 gal = $214

Check your learning

A Toyota Prius Hybrid uses 59.7 L gasoline to drive from San Francisco to Seattle, a distance of 1300 km (two significant digits).

(a) What (average) fuel economy, in miles per gallon, did the Prius get during this trip?

(b) If gasoline costs $3.90 per gallon, what was the fuel cost for this trip?


(a) 51 mpg; (b) $62

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Conversion of temperature units

We use the word temperature to refer to the hotness or coldness of a substance. One way we measure a change in temperature is to use the fact that most substances expand when their temperature increases and contract when their temperature decreases. The mercury or alcohol in a common glass thermometer changes its volume as the temperature changes. Because the volume of the liquid changes more than the volume of the glass, we can see the liquid expand when it gets warmer and contract when it gets cooler.

To mark a scale on a thermometer, we need a set of reference values: Two of the most commonly used are the freezing and boiling temperatures of water at a specified atmospheric pressure. On the Celsius scale, 0 °C is defined as the freezing temperature of water and 100 °C as the boiling temperature of water. The space between the two temperatures is divided into 100 equal intervals, which we call degrees. On the Fahrenheit    scale, the freezing point of water is defined as 32 °F and the boiling temperature as 212 °F. The space between these two points on a Fahrenheit thermometer is divided into 180 equal parts (degrees).

Defining the Celsius and Fahrenheit temperature scales as described in the previous paragraph results in a slightly more complex relationship between temperature values on these two scales than for different units of measure for other properties. Most measurement units for a given property are directly proportional to one another (y = mx). Using familiar length units as one example:

length in feet = ( 1 ft 12 in. ) × length in inches

where y = length in feet, x = length in inches, and the proportionality constant, m, is the conversion factor. The Celsius and Fahrenheit temperature scales, however, do not share a common zero point, and so the relationship between these two scales is a linear one rather than a proportional one (y = mx + b). Consequently, converting a temperature from one of these scales into the other requires more than simple multiplication by a conversion factor, m, it also must take into account differences in the scales’ zero points (b).

Questions & Answers

the first fifty elements
Joy Reply
how to complete and balance ionic equation?
what is molar mass?
Wendy Reply
Molar mass is defined as the mass of a sample of a compound divided by the amount of substance of that sample.
or M=m\n mathematically.
atom is the smallest indivisible part of an element that takes place in chemical reaction
Obinna Reply
An atom is the smallest indivisible part of an element
what is periodic table
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what is an atom?
is the study of matter and the changes it under goes.
under goes through three state they are solid liquid and gas
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please what is hydroxyl group
Gold Reply
the hydroxyl group is a functional group consisting of a hydrogen atom covalently bonded to an oxygen atom.
Names are of homologous series
Josiah Reply
what's an hydroxyl group?
A hydroxy or hydroxyl group is the entity with the formula OH. It contains oxygen bonded to hydrogen. In organic chemistry, alcohols and carboxylic acids contain hydroxy groups. The anion [OH⁻], called hydroxide, consists of a hydroxyl group. 
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what's organic chemistry?
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please what is maa
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Because it's mass it very very small compare with mass of atom
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consider the rxn of butadiene .Butadiene is prepared by the gas phase catalytic dehydrogenation of 1-butene , at 900K and 1 bar. c4H8 (g)_ C4H6 (g) + H2 (g) (a) In order to suppress side reactions , the butane is diluted with steam before it passes into the reactor.Estimate the conversion
Estimate the conversion of 1-butene for a feed consisting of 10 moles of steam per mole of 1-butene. (b) find the conversion if the inerts were absent and side reactions are ignored .
help me please I have tried
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for now chemistry is the study of matter and it properties, why and how element combined to form other substances
Chemistry is a group that identifies properties of matter and many more
Wow and chemistry also is the systematic study of nature
chemistry is the study of the structure, properties of matter and the effect of addition or removal of heat from substances.
calculate the relative molecular Mass of the following 1 ZnCl2 2 NaNo3 3 HNO3 4 CaO
Reuben Reply
2) 23+14+(16×3)= 3)1+14+(16×3)= 4) 40+16= 1) Zn+71= that's how they do it but for Zn I don't know its mass number
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What is radioactivity
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radioactivity is the spontaneous disintegration of the nucleus of an atom of an element to emmit radiation
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Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
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