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]
2 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]2 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
What is the noble gas electron configuration of bismuth (Bi)? A. [Kr] 6s2 6p3 B. [Xe] 6s2 6p3 C. [Xe] 4f14 5d10 6s2 6p3 D. [Kr]
OlgaM077 [116]

The answer is C) Xe 4f14 5d10 6s2 6p3

4 0
3 years ago
Read 2 more answers
Whenever a continuous bell alarm sounds in the Chemistry building:
deff fn [24]

Answer:

C

Explanation:

This is essentially one of the several safety measures in the chemical laboratory. This particular approach is one used in the case of fire eventualities.

A is wrong

This is because in the advent of a fire incident, it is necessary to evacuate the building as a whole. Meeting in the hallway is still within the building which is not the right thing to do when there’s a fire outbreak. Occupants are expected to leave the building immediately

B. Is also wrong. Taking time to pack your belongings might make you be caught in the inferno. It is expected that you leave the building at once

4 0
3 years ago
A rock that has a mass if 180 grams dropped in a graduated cylinder that was originally filled to 52ml; it now reads 62ml. What
Vlad [161]

Answer:

<h2>18 g/mL</h2>

Explanation:

The density of a substance can be found by using the formula

density =  \frac{mass}{volume} \\

volume = final volume of water - initial volume of water

volume = 62 - 52 = 10 mL

From the question we have

density =  \frac{180}{10}  \\

We have the final answer as

<h3>18 g/mL</h3>

Hope this helps you

5 0
3 years ago
What is a solubility?
kogti [31]

Answer:the ability to be dissolved, especially in water.

Explanation:

6 0
3 years ago
What is the mass of a 5.00 cm^3 piece of copper having a density of 8.96 g/cm^3
erik [133]

Answer:

44.8 g

Explanation:

Density = mass / Volume

Mass = density x Volume = 8.96x 5 = 44.8 g

5 0
3 years ago
Other questions:
  • Which part of the electromagnetic spectrum has the lowest radiant energy?
    5·2 answers
  • Which of the following is the CORRECT path taken by sperm from site of production to site of ejection? A. epididymis, seminifero
    12·1 answer
  • Digestion is the process of breaking down food into substances that the can use. Which of the following is a physical change tha
    12·2 answers
  • In bowen's discontinuous reaction series, the first mineral to crystallize out of a mafic melt is __________ .
    9·1 answer
  • While driving your rental car on your vacation in Europe, you find that you are getting 8.8 km/L of gasoline. What does this val
    14·1 answer
  • Can someone please help me?
    8·1 answer
  • Explain what makes a cirrus cloud.
    7·1 answer
  • Determine the atomic number, atomic mass and element name of the following:
    13·1 answer
  • Write the balanced equation for the spontaneous cell reaction that occurs in a cell with these reduction half-reactions.
    6·1 answer
  • If you have 85.0 grams of CO₂, calculate how many moles of CO₂ would you have?
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!