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
Anna71 [15]
2 years ago
12

When oxygen reacts with hydrogen, it has the capacity to release 29 kilojoules of energy. Inside a fuel cell, oxygen reacts with

hydrogen to produce 23 kilojoules of useful energy. The rest of the energy is lost as heat. What’s the efficiency percentage of the fuel cell?
: 25 points
Chemistry
1 answer:
Pachacha [2.7K]2 years ago
6 0

Answer:

Explanation:

<h2>help mo soon</h2>
You might be interested in
Can someone explain this please?<br> What are sound waves?
In-s [12.5K]

Answer:

sound waves is what causes you and thing with be able to hears sounds and things

5 0
3 years ago
Read 2 more answers
Why parafin oil use in melting
MatroZZZ [7]

Answer:

Paraffin oil is used for determination of boiling point and melting point for the following reasons: It has a very high boiling point and so it can be used to maintain high temperatures in the boiling and melting point apparatus without loss of the substance.

4 0
2 years ago
An experiment applies heat to a substance and produces a gas that is a new and different substance. Choose the true statement.
sergejj [24]
Im a bit torn here, lets look at the definitions of physical and chemical changes:
physical change changes only the phase/state of a substance, but not what the substance is
chemical change is a chemical reaction where a new substance is formed and energy is given off or absorbed.
(it just started raining and it smells really nice out my window)

clearly, this cannot be just a physical reaction. i think i would be inclined to pick B. but C. could have merit as an answer too. sorry for the ambiguity x
7 0
3 years ago
Which of the following gases would diffuse the fastest? <br> CH 4<br> CCl 4 <br> O 2<br> H 2
Sholpan [36]
H2 <span>because the smaller the gas molecule, the faster the diffusion. (the lightest molecule will diffuse the quickest)</span>
8 0
3 years ago
What volume (in liters) of a solution contains 0.14 mol of KCl?
oksano4ka [1.4K]

Answer:

\boxed {\boxed {\sf 0.078 \ L }}

Explanation:

We are asked to find the volume of a solution given the moles of solute and molarity.

Molarity is a measure of concentration in moles per liter. It is calculated using the following formula:

molarity= \frac{moles \ of \ solute}{liters \ of \ solution}

We know there are 0.14 moles of potassium chloride (KCl), which is the solute. The molarity of the solution is 1.8 molar or 1.8 moles of potassium chloride per liter.

  • moles of solute = 0.14 mol KCl
  • molarity= 1.8 mol KCl/ L
  • liters of solution=x

Substitute these values/variables into the formula.

1.8 \ mol \ KCl/ L = \frac { 0.14 \ mol \ KCl}{x}

We are solving for x, so we must isolate the variable. First, cross multiply. Multiply the first numerator and second denominator, then the first denominator and second numerator.

\frac {1.8 \ mol \ KCl/L}{1} = \frac{0.14 \ mol \ KCl}{x}

1.8 \ mol \ KCl/ L *x = 1*0.14 \ mol \ KCl

1.8 \ mol \ KCl/ L *x = 0.14 \ mol \ KCl

Now x is being multiplied by 1.8 moles of potassium chloride per liter. The inverse operation of multiplication is division, so we divide both sides by 1.8 mol KCl/L.

\frac {1.8 \ mol \ KCl/ L *x}{1.8 \ mol \ KCl/L} = \frac{0.14 \ mol \ KCl}{1.8 \ mol \ KCl/L}

x= \frac{0.14 \ mol \ KCl}{1.8 \ mol \ KCl/L}

The units of moles of potassium chloride cancel.

x= \frac{0.14 }{1.8 L}

x=0.07777777778 \ L

The original measurements of moles and molarity have 2 significant figures, so our answer must have the same. For the number we found, that is the thousandth place. The 7 in the ten-thousandth place tells us to round the 7 up to a 8.

x \approx 0.078 \ L

There are approximately <u>0.078 liters of solution.</u>

5 0
3 years ago
Other questions:
  • What will be the volume of a balloon at 98 kPa if its volume is 9.65 L at 235 kPa?
    7·1 answer
  • Which component is missing from the process of cellular respiration? Glucose + Oxygen → Carbon Dioxide + ________ + Energy
    13·2 answers
  • A The Haber process is typically carried out at a temperature of approximately 500∘C. What would happen to the rate of the forwa
    13·1 answer
  • What mechanical weathering process is used when water turns to ice?
    13·2 answers
  • PlzzzHelp help help plz
    7·2 answers
  • Que representa en la reacción química <br> Na2SO4(s)+H2O(1)=
    15·1 answer
  • If you start with 30.0 grams of sodium fluoride, how many grams of magnesium fluoride will be produced?
    15·1 answer
  • _______ is a physical property
    10·2 answers
  • CO2 + H2O + C6H12O6 +02
    7·1 answer
  • What Group is this element in?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!