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
gizmo_the_mogwai [7]
3 years ago
8

Determine the heat given off to the surroundings when 9.0 g of aluminum (fm = 26.98) reacts according to the equation 2al + fe2o

3 → al2o3 + 2fe, δh°rxn= –849 kj/mol
Chemistry
1 answer:
Akimi4 [234]3 years ago
8 0

Hey there!:

Number of moles:

Molar Mass Al = 26.98 g/mol

n = mass / molar mass

n = 9.0 / 26.98

n = 0.3336 moles of Al

Given the reaction :

2 Al + Fe2O3 = Al2O3 + 2 Fe

From the equation, 2 moles of Al give off 849 kJ of heat :

Actual heat given off :

0.3336 / 2 * 849 =

0.3336 / 1698 = 1.4*10² Kj


Hope that helps!


You might be interested in
A chemical equation is balanced when the number of atoms of each type of _____ is the same on both sides of the equation.
vovikov84 [41]

Answer:

hi i think it's element .

7 0
2 years ago
A toothpaste contains sodium fluoride (NaF) What percentage of Fluoride is present.(4cs)
MariettaO [177]

Answer:

45.2%

Explanation:

To calculate the percent of an element in a compound we divide the molar mass of the element by the compound and multiply that by 100

First lets find the molar mass of Fluoride

Looking at the periodic table Fluoride has a molecular mass of 18.998 g

Now we need to find the molecular mass of NaF

Looking at a periodic table, Sodium (Na) has a molecular mass of 22.990g and Fluoride has a molecular mass of 18.998 so NaF has a molecular mass of 22.990(1) + 18.998(1) = 41.988g

Now we divide the mass of fluoride by the mass of sodium fluoride and multiply that by 100 to find the percentage of fluoride that is present in NaF

Mass of Fluoride = 18.998g

Mass of Sodium Fluoride = 41.988g

Percentage of fluoride present in NaF = (18.998g / 41.988g) * 100 = 45.2%

7 0
3 years ago
What are the coinage elements ?
kupik [55]

The elements of a coin.

7 0
3 years ago
Why is atmospheric pressure much lower on the top of a mountain than it is as sea level?
Vika [28.1K]
Because the gravity levels decrese and so does the oxygen levels

3 0
3 years ago
Read 2 more answers
Which of the following is unchanged at the end of the CNO cycle?
Musya8 [376]

Answer:

The correct option is: A. carbon-12

Explanation:

The CNO cycle, the abbreviation for the carbon-nitrogen-oxygen cycle, is a catalytic cycle by which the stars produce helium from elemental hydrogen, via a series of nuclear fusion reactions.

This cycle involves the fusion of four protons with carbon (_{6}^{12}\textrm{C}), nitrogen isotope (_{7}^{13}\textrm{N}), and oxygen isotope (_{8}^{15}\textrm{O}), to give an alpha particle and two electron neutrinos and positrons.

The reaction involves the regeneration of carbon (_{6}^{12}\textrm{C}) nucleus in the last step.

_{6}^{12}\textrm{C} → _{7}^{13}\textrm{N} → _{6}^{13}\textrm{C} → _{7}^{14}\textrm{N} → _{8}^{15}\textrm{O} → _{7}^{15}\textrm{N} → _{6}^{12}\textrm{C}

3 0
3 years ago
Other questions:
  • How do I do question C?! Mass to moles
    12·1 answer
  • The isotope of an atom containing 31 protons and 39 neutrons suddenly has two neutrons added to it. what isotope is created? loo
    5·2 answers
  • A 3.00 g sample of unknown hydrocarbon is prepared for combustion analysis. after the hydrocarbon undergoes complete combustion,
    13·1 answer
  • How are science and technology related?
    11·2 answers
  • !!!!HELP ASAP 10 points!!!Which of the following families contains liquids, solids, and gases?
    12·2 answers
  • PLEASE HELP ME WITH THESE TWO QUESTIONS!!MY CHEMISTRY QUIZ IS DUE AT MIDNIGHT:(
    13·1 answer
  • A gas is initially at a pressure of 0.43 atm, and a volume of 11.7 liters. Then the pressure is raised to 3.61 atm and the volum
    12·2 answers
  • Given the density of iron (Fe) is 7.87 g/cm3, determine the mass of iron (in grams) in a rectangle block with the dimensions of
    12·1 answer
  • Which two factors are leading to an increased use of natural resources?
    12·1 answer
  • Negative radical in the periodic table<br>​
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!