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
iragen [17]
3 years ago
6

Q15. Natural gas burns in air to form carbon dioxide and water to releasing heat. CHA(g) O2 (g) CO2 g) H20 (g) AH 802.3 kJ What

minimum mass of CH4 is required to heat 55 g of water by 25 °C? (Assume 100% heating efficiency. c) 115 g a) 0.115 g b) 2.25 x 103 g d) 8.70 g
Chemistry
1 answer:
mestny [16]3 years ago
6 0

Answer:

a) 0.115 g

Explanation:

The balanced reaction is:

CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g)

To heat 55g of water, the energy in form of heat necessary can be calculated by:

Q = mcΔT

where Q is the heat, m is the mass, c is the specific heat (for water, c = 4.18 J/gºC), and ΔT is the variation of the temperature, which is 25ºC, so:

Q = 55x4.18x25

Q = 5747.5 J = 5.7475 kJ

So, for the reaction, 1 mol of CH₄ releases 802.3 kJ, so to release 5.7475 kJ will be necessary:

1 mol ---------------- 802.3 kJ

x ---------------- 5.7475 kJ

By a simple direct three rule:

802.3x = 5.7475

x = 7.164x10⁻³mol

The molar mass of CH₄ is : 12 (of C) + 4x1 (of H) = 16 g/mol

The mass is equal to the number of moles multiplied by molar mass, the:

m = 7.164x10⁻³x16

m = 0.115 g

You might be interested in
A solution is prepared by dissolving 20.1 g of MgCl2 with the addition of 157.0 mL of water (density of water is 1.00g/cm3). The
Nezavi [6.7K]

Answer:

1.3 M.

Explanation:

  • We need to calculate the mass of the solution:

mass of the solution = mass of MgCl₂ + mass of water

mass of MgCl₂ = 20.1 g.

mass of water = d.V = (157.0 mL)(1.0 g/cm³) = 157.0 g.

∴ mass of the solution = mass of MgCl₂ + mass of water = 20.1 g + 157.0 g = 177.1 g.

  • Now, we can get the volume of the solution:

V of the solution = (mass of the solution)/(density of the solution) = (177.1 g)/(1.089 g/cm³) = 162.62 mL = 0.163 L.

Molarity is the no. of moles of solute dissolved in a 1.0 L of the solution.

M = (no. of moles of MgCl₂) / (Volume of the solution (L)).

<em>∴ M = (mass/molar mass)of MgCl₂ / (Volume of the solution (L)) =</em> (20.1 g/95.211 g/mol) / (0.163 L) = <em>1.29 M ≅ 1.3 M.</em>

6 0
3 years ago
Which of the following is a scientific question? O A. How can I make a peach cobbler? O B. What chemicals cause most plants to b
igor_vitrenko [27]
The answer is B. Because think about it, it’s not a scientific fact that brown dogs are better pets, and the best color for your room isn’t it because the answer would be an opinion of someone not a fact. I hope this might help you.
5 0
3 years ago
Enter the molecular equation representing aqueous nitric acid and aqueous ammonia reacting. express your answer as a balanced mo
PtichkaEL [24]
Aqueous nitric acid and aqueous ammonia reacts to form ammonium nitrate 
 HNO₃(aq)+NH₃(aq) = NH₄NO₃(aq)
 HNO₃ +NH3 = NH₄ (+) + NO₃ (-)
Therefore the net ionic equation will be;
 H⁺(aq) + NH₃ = NH₄⁺ (aq)

4 0
3 years ago
Read 2 more answers
How can you use chemistry to enhance ground transportation vehicles and reduce pollution?
Svetradugi [14.3K]

Answer:

Ride a bike or walk. If you are only going a short distance, consider riding a bike or walking instead of driving. ...

Take public transit. ...

Carpool. ...

Avoid idling. ...

Use alternative fuels.

3 0
2 years ago
Which of the following organisms would NOT be in the first trophic level of an energy pyramid?
faust18 [17]
dog!

this is because the first energy comes from plants bc they can make their own food— therefore, energy :)
7 0
3 years ago
Read 2 more answers
Other questions:
  • Which of the following statements is not correct?
    6·1 answer
  • What is the most effective way to maintain good indoor air quality?
    14·1 answer
  • True or false that La Niña creates cooler temperatures than El Niño.
    12·1 answer
  • In another experiment, if 80 xo3 molecules react with 104 brz3 molecules how many br2 molecules will be produced which reactant
    8·1 answer
  • Which best describes the law of conservation of mass? The coefficients in front of the chemicals in the reactants should be base
    15·2 answers
  • A 28.5 gram piece of iron is added to a graduated cylinder containing 45.5 mL of water. The water in the cylinder rises to the 4
    15·1 answer
  • What are the reactants in photosynthesis?
    8·2 answers
  • What does the Coriolis effect describe
    12·1 answer
  • 1. What makes a plant vacuole different from an animal vacuole? |
    14·1 answer
  • Which of the following subatomic particles are found surrounding the nucleus and have a negative charge?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!