1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
masya89 [10]
3 years ago
14

Denise owns a car that runs on a mixture of gasoline and ethanol. She can buy fuels that have 85% ethanol or 25% ethanol. How mu

ch of each type of fuel should she buy if she wants to fill her 20-gallon tank with a mixture of fuel that contains 50% ethanol?
Chemistry
1 answer:
Hunter-Best [27]3 years ago
5 0
<span>85% ethanol | 25% ethanol | 50% ethanol
x | y | 20 gal

use x and y because you don;t know how much she needs.

0.85x | 0.25y | 20(0.5)

85% is 85/100 or 0.85, and you need that much of x, same goes for the 25% and 50% mixtures so now you can make up 2 equations
1) x + y = 20 2) 0.85x + 0.25y= 10 (you get 10 when you multiply 20 by 0.5) now you can solve for x or y using substitution.
first rewrite 1) in terms of x or y: x+ y= 20 ----> y= 20 - x now you can substitute 20- x for y in the second equation.. 0.85x + 0.25y= 10 0.85x + 0.25(20-x)= 10 distribute here..(0.25 * 20 and 0.25 * (-x) ) 0.85x + 5 - 0.25x = 10 combine like terms 0.6x +5 = 10 move the 5 over to the other side 0.6x= 10 -5 0.6x = 5 divide both sides by 0.6 x= 25/3 or 8.3 now you know the amount of x so you can substitue this back into the first equation to find y. 0.85x + 0.25y= 10 0.85(25/3) +0.25y= 10 85/12 + 0.25y= 10 0.25y = 10- 85/12 0.25y= 35/12 y= 35/3 or 11.6 you can check by putting these values into the euations: 1) x+ y= 20 25/3 + 35/3 =20 20= 20 good so far 2) 0.85x + 0.25y= 10 0.85(25/3) + 0.25(35/3)=10 10 = 10

so our values for x and y work
x= 25/3 and y= 35/3</span>
You might be interested in
in a mixture of 1.90 mol of gas, 0.85 mol are nitrogen (n2) molecules. what is the mole fraction of n2 in this mixture?
Nostrana [21]

0.447 is the mole fraction of Nitrogen in this mixture.

mole fraction of nitrogen= moles of nitrogen/total moles

mole fraction of nitrogen=0.85/1.90

mole fraction of nitrogen=0.447

The product of the moles of a component and the total moles of the solution yields a mole fraction, which is a unit of concentration measurement. Because it is a ratio, mole fraction is a unitless statement. The sum of the components of the mole fraction of a solution is one. In a mixture of 1 mol benzene, 2 mol carbon tetrachloride, and 7 mol acetone, the mole fraction of the acetone is 0.7. This is computed by dividing the sum of the moles of acetone in the solution by the total number of moles of the solution's constituents:

To know more about mole fraction visit : brainly.com/question/8076655

#SPJ4

4 0
1 year ago
What protects the plant embryo?
Pani-rosa [81]
How do seed plants protect their embryos?
Reptilian embryos are protected from desiccation by a leathery shell. Similarly, sporophytes of both gymnosperms and angiosperms protect embryos within, and they also protect male gametophytes against desiccation using .....
5 0
3 years ago
The usual units of density are : <br> cm3/ g<br> cm2/g<br> g/cm<br> Nm
Ad libitum [116K]
The usual units of density are g/cm.

You may have also seen g/mL used for density. Keep in mind that 1 cm = 1 mL.
3 0
3 years ago
Read 2 more answers
What are the substances making up a mixture called
dimulka [17.4K]

  • The substance that made up of a particular mixture can be regarded as Solute and solvent

  • A  mixture can be regarded as material which is made up of  more than one  different Chemical substance or substances , whereby they  are not chemically combined.

  • Substance could be any matter such as <em>salt, rice, and or compounds</em>

  • A mixture can be regarded as physical combination involving two or more substances whereby each entities identities are retained, then mixed in the form such as ;
  1. <em>solutions</em>
  2. <em> suspensions </em>
  3. <em> colloids</em>.

  • A mixture could be  in this form <em>(Solute + solvent = solution)</em>

Therefore, the substance that made up of a particular mixture can be regarded as <em>Solute and solvent</em>

Learn more at: brainly.com/question/18569341

7 0
3 years ago
At 40 mph, how long does it take to travel 64 miles
gogolik [260]
1.5 hours
explanation: don’t have one just trust me
6 0
2 years ago
Other questions:
  • How does a change in temperature affect the kinetic energy of the particles in a reaction?
    8·1 answer
  • What is it called when an atom has the same number of protons but a different number of neutrons?
    10·2 answers
  • A species that is isoelectronic with the nitrate ion and hence would have the same shape is [1] [2] [3] [4] [5] sulphur trioxide
    6·1 answer
  • A app181.studyisland.com
    8·1 answer
  • C3H8+5O2 →3CO2+4H20,
    12·1 answer
  • Describe the composition of a molecular compound. What are two major characteristics of molecular compounds?
    7·1 answer
  • How many centimeters are in 5 miles? Hint: 1 miles = 5280 feet
    13·1 answer
  • A gas has a volume of 240.0mL at 25.0 oC and 0.79 atm. Calculate its volume at STP (1 atm and 0 oC).
    14·1 answer
  • Characteristics of a substance that can be measured or observed by changing the identity of the material is a
    14·1 answer
  • Board cases involving eligibility or disciplinary issues that are resolved through a board agreed order
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!