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
pychu [463]
3 years ago
9

Calculate the enthalpy change, ∆H in kJ, for the reaction H2O(s) → H2(g) + 1/2O2(g). Use the following information: : +279.9 kJ

+291.9 kJ –279.9 k –291.9 kJ
Chemistry
1 answer:
Len [333]3 years ago
5 0

Answer:

+ 291.9 kJ

Solution:

The equation given is as;

H₂O ₍s₎ → H₂ ₍g₎ + 1/2 O₂ ₍g₎ ΔH = ?

First, as we know the heat of formation of H₂O ₍l₎ is,

H₂ ₍g₎ + 1/2 O₂ ₍g₎ → H₂O ₍l₎ ΔH = - 285.9 kJ

Now, reversing the equation will reverse the sign of heat as,

H₂O ₍l₎ → H₂ ₍g₎ + 1/2 O₂ ₍g₎ ΔH = + 285.9 kJ

Also, we know that,

H₂O ₍s₎ → H₂O ₍l) ΔH = + 6.0 kJ

Now, adding last two equations,

H₂O ₍l₎ → H₂ ₍g₎ + 1/2 O₂ ₍g₎ ΔH = + 285.9 kJ

H₂O ₍s₎ → H₂O ₍l) ΔH = + 6.0 kJ

-----------------------------------------------------------------------------

H₂O ₍s₎ → H₂ ₍g₎ + 1/2 O₂ ₍g₎ ΔH = + 291.9 kJ

You might be interested in
4 On a bright, sunny day, which time of day can
Marina CMI [18]
It has to be J. 12:00am cause at night that’s when everything
5 0
3 years ago
Drag each tile to the correct location on the image.
nikdorinn [45]

Answer:

[He]: 2s² 2p⁵.

[Ne]: 3s².

[Ar]: 4s² 3d¹⁰ 4p².

[Kr]: 5s² 4d¹⁰ 5p⁵.

[Xe]: 6s² 4f¹⁴ 5d¹⁰ 6p².

Explanation:

  • Noble elements are used as blocks in writing the electronic configuration of other elements as they are stable elements.

  • [He]:

He contains 2 electrons fill 1s (1s²).

So, [He] can be written before the electronic configuration of 2s² 2p⁵.

  • [Ne]:

Ne contains 10 electrons fill (1s² 2s² 2p⁶).

So, [Ne] can be written before the electronic configuration of 3s².

  • [Ar]:

Ar contains 18 electrons is configured as ([Ne] 3s² 3p⁶).

So, [Ar] can be written before the electronic configuration of 4s² 3d¹⁰ 4p².

  • [Kr]:

Kr contains 36 electrons is configured as ([Ar] 4s² 3d¹⁰ 4p⁶).

So, [Kr] can be written before the electronic configuration of 5s² 4d¹⁰ 5p⁵.

  • [Xe]:

Xe contains 54 electrons is configured as ([Kr] 5s² 4d¹⁰ 5p⁶).

So, [Xe] can be written before the electronic configuration of 6s² 4f¹⁴ 5d¹⁰ 6p².

3 0
3 years ago
Read 2 more answers
Give explanations for the large drops in melting point from C to Si and from Ge to Sn.
____ [38]

As we move down the group, the metallic bond becomes more stable and the formation of forming covalent bond decreases down the group due to the large size of elements.

Covalent and metallic bonding leads to higher melting points. Due to a decrease in attractive forces from carbon to lead there is a drop in melting point.

Carbon forms large covalent molecules than silicon and hence has a higher melting point than silicon.

Similarly, Ge also forms a large number of covalent bonds and has a smaller size as compared to that of Sn. Hence melting point decreases from Ge to Sn.

The order will be C>Si>Ge>Pb>Sn.

To learn more about the covalent bond, visit: brainly.com/question/10777799

#SPJ4

3 0
1 year ago
What causes the "heat island" effect?
Arada [10]
D all of the above answers are correct
6 0
3 years ago
For a fixed amount of gas at a fixed volume, what will happen if the absolute temperature is doubled?
Firlakuza [10]
The answer to this question is: The pressure will be increased two times

The gas law includes an interaction of pressure(p), volume(V) and temperature(T). In this case, the gas has same amount and volume but then the temperature is doubled. The calculation would be:

p1 * V1 / T1= p2*V2 /T2 
p1 * 1 / 1 = p2 * 1 / 2
p1 / (1/2)=p2
p2= 2* p1
8 0
3 years ago
Other questions:
  • Which shows the loudest sound?
    13·1 answer
  • Given that P-31 is the only natural isotope of phosphorus, what is the mass of one P atom and the mass of Avogadro's number of P
    8·2 answers
  • What is the energy of an electromagnetic wave with a electromagnetic wave with a frequency of 3 * 10 Hz ?
    12·1 answer
  • What is the mass of 0.59L of SO2 at STP?
    12·1 answer
  • As rocks erode from Earth's surface, they are replaced by the process ____of
    11·1 answer
  • Brainliest if CORRECT<br><br><br><br><br><br><br> 11
    14·2 answers
  • How many moles of aluminum are in this aluminum can? Answer: ____________ (25 pts) Calculate the number of aluminum atoms in thi
    12·1 answer
  • 4.
    13·1 answer
  • What kind of soap is the best?
    13·2 answers
  • A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive a
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!