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
Gnom [1K]
3 years ago
10

What quantity, in moles, of oxygen is consumed when 717.4 kJ of energy is evolved from the combustion of a mixture of H2(g) and

O2(g)? H2(g) + O2(g) → H2O(l); ΔH° = –285.8 kJ
Chemistry
1 answer:
mars1129 [50]3 years ago
6 0

Answer: 2.51 moles of oxygen is consumed

Explanation:

Exothermic reaction : It is a type of chemical reaction where the energy is released into the surrounding. In the exothermic reaction, the energy of reactant are more than the energy of product.

In exothermic reaction, the change in enthalpy is, negative

The balanced chemical reaction is:

2H_2(g)+O_2(g)\rightarrow 2H_2O(l) \Delta H=-285.8kJ

According to stoichiometry:

When 1 mole of oxygen is consumed , energy released = 285.8 kJ

285.8 kJ of energy is evolved when oxygen consumed = 1 mol

Thus whn 717.4 kJ of energy is evolved when oxygen consumed = \frac{1}{285.8}\times 717.4=2.51 moles

2.51 moles of oxygen is consumed

You might be interested in
A sample of gas with an initial volume of 12.5 L at a pressure of 784 torr and a temperature of 295 K is compressed to a volume
Kipish [7]

Answer:

Final pressure in (atm) (P1) = 6.642 atm

Explanation:

Given:

Initial volume of gas (V) = 12.5 L

Pressure (P) = 784 torr

Temperature (T) = 295 K

Final volume (V1) = 2.04 L

Final temperature (T1) = 310 K

Find:

Final pressure in (atm) (P1) = ?

Computation:

According to combine gas law method:

\frac{PV}{T} =\frac{P1V1}{T1} \\\\\frac{(784)(12.5)}{295} =\frac{(P1)(2.04)}{310}\\\\33.22 = \frac{(P1)(2.04)}{310}\\\\P1=5,048.18877

⇒ Final pressure (P1) = 5,048.18877 torr

⇒ Final pressure in (atm) (P1) = 5,048.18877 torr / 760

⇒ Final pressure in (atm) (P1) = 6.642 atm

3 0
3 years ago
What is the name of an element that have a atomic number of 82 and the atomic number of 207
balandron [24]
This element is Lead (Pb).
5 0
3 years ago
14. A piece of titanium at 100.0°C was dropped into 50.0 g of water at 20.0°C. The final temperature of the system was 22.6°C. W
Gemiola [76]

Answer:

m_{Ti}=13.0g

Explanation:

Hello,

In this case, based on the given, we can infer that as titanium is hot and water cold, it cools down whereas the water is heated up, therefore, in terms of heat, we have that the heat lost by the titanium is gained by the water:

-Q_{Ti}=Q_{H_2O}

That in terms of mass, specific heat and temperatures is:

-m_{Ti}Cp_{Ti}(T_2-T_{Ti})=m_{H_2O}Cp_{H_2O}(T_2-T_{H_2O})

In such a way, for computing the mass of titanium, considering the heat capacity of water 4.18 J/g°C, we have:

m_{Ti}=\frac{m_{H_2O}Cp_{H_2O}(T_2-T_{H_2O})}{-Cp_{Ti}(T_2-T_{Ti})} \\\\m_{Ti}=\frac{50.0g*4.18\frac{J}{g\°C}(22.6-20.0)\°C}{-0.54\frac{J}{g\°C}*(22.6-100.0)\°C} \\\\m_{Ti}=13.0g

Regards.

8 0
3 years ago
Why is helium considered as a noble gas
dolphi86 [110]
Noble gases are known for having a full outer shell of electrons which helium has as it has two electrons its first electron shell is completely filled

7 0
3 years ago
Read 2 more answers
A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO3)2 with 50.0 mL of 0.50 M Co(NO3)2. Sodium hydroxide is added to the mi
vekshin1

Answer:

Cu(OH)₂ will precipitate first, with [OH⁻] = 2.97x10⁻¹⁰ M

Explanation:

The equilibriums that take place are:

Cu⁺² + 2OH⁻ ↔ Cu(OH)₂(s)   ksp = 2.2x10⁻²⁰ = [Cu⁺²]*[OH⁻]²

Co⁺² + 2OH⁻ ↔ Co(OH)₂(s)   ksp = 1.3x10⁻¹⁵ = [Co⁺²]*[OH⁻]²

Keep in mind that <em>the concentration of each ion is halved </em>because of the dilution when mixing the solutions.

For Cu⁺²:

2.2x10⁻²⁰ = [Cu⁺²]*[OH⁻]²

2.2x10⁻²⁰ = 0.25 M*[OH⁻]²

[OH⁻] = 2.97x10⁻¹⁰ M

For Co⁺²:

1.3x10⁻¹⁵ = [Co⁺²]*[OH⁻]²

1.3x10⁻¹⁵ = 0.25 M*[OH⁻]²

[OH⁻] = 7.21x10⁻⁸ M

<u>Because Copper requires less concentration of OH⁻ than Cobalt</u>, Cu(OH)₂ will precipitate first, with [OH⁻] = 2.97x10⁻¹⁰ M

3 0
3 years ago
Other questions:
  • The question is what does it regulate. PLEASE HELP. 1 sentence for each will help
    9·2 answers
  • You need 4.0 ounces of a steroid ointment. if there are 16 oz in 1 lb, how many grams of ointment does the pharmacist need to pr
    10·1 answer
  • How many moles of water are in 1.23x10^18 water molecules
    10·2 answers
  • Using off-road vehicles does not contribute to the process of erosion. true or false
    12·2 answers
  • What is the density of a block of marble that occupies 287cm3 and has a mass of 869g?
    5·1 answer
  • FORENSIC SCIENCE HELP
    7·1 answer
  • How many grams of Ca metal are produced by the electrolysis of molten CaBr2 using a current of 30.0 amp for
    11·1 answer
  • Erika is asked to create a model showing a negatively charged Carbon ion. Which model should she create?
    6·1 answer
  • 3. How many atoms in 3.91 moles of sodium?
    7·1 answer
  • For the following equation to be bal
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!