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
Roman55 [17]
3 years ago
12

What is a observation ?

Chemistry
1 answer:
SOVA2 [1]3 years ago
6 0
An active skill of information from a primary source
You might be interested in
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
Hunter-Best [27]
<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>
5 0
3 years ago
Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the
Aleks04 [339]

Answer:

A = True

B = False

C = True.

I think this is the answer

8 0
3 years ago
If an equilibrium system contains gaseous reactants and/or products, a change in volume will cause a change in concentration and
mihalych1998 [28]

Answer:

Less

More

Explanation:

When a constraint is imposed on a reaction system in equilibrium, the equilibrium position will shift in such a way as to annul the constraint.

When the volume of a reaction system in equilibrium is decreased, the equilibrium position will shift in the direction having less total number of moles.

Similarly, when the volume is increased, the equilibrium position shifts to the direction having a greater total number of moles.

6 0
3 years ago
In a chemical equation, the sum of the masses ______.
Readme [11.4K]
C. Of the products is equal to the reactants.

Good luck out there! :)
5 0
3 years ago
Read 2 more answers
Why potassium by sulphite or KHSO4 donot preserve meat
Debora [2.8K]

Answer:

Postassium bisulphate - KHSO4 - can be used as an food preservative to protect the food from micro-organisms.

4 0
3 years ago
Other questions:
  • How many valence electrons are needed for a 'complete set' of electrons?
    5·1 answer
  • Indicate the number of significant figures in the measured number 5.80
    7·1 answer
  • Identify atoms that are isotopes in each of the following sets of four atoms.
    12·2 answers
  • Which of these is a physical property?
    11·2 answers
  • A particular reaction, A- products, has a rate that slows down as the reaction proceeds. The half-life of the reaction is found
    12·1 answer
  • A extensive property of a pot of boiling water would be its
    15·2 answers
  • Choose any electromagnetic wave we have discussed and write ONE PARAGRAPH telling me about the uses/benefits of that electromagn
    7·2 answers
  • The substance krypton has the following properties: normal melting point:
    5·1 answer
  • What happens to weather patterns when a cold front approaches? Answer in complete sentences. Its timed!! YOU WILL GET BRAINLIEST
    15·1 answer
  • 1. What did Henri Becquerel discover about<br> radiation emitted from uranium salts?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!