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
VMariaS [17]
3 years ago
13

14.7 grams of magnesium reacts completely with 9.7 grams of oxygen to form magnesium oxide (MgO). What is the percent compositio

n of the magnesium oxide?
Chemistry
1 answer:
swat323 years ago
5 0
The answer is 60.3% magnesium, 39.7% oxygen.
Solution:
The chemical equation for the reaction is 2 Mg + O2 → 2 MgO.
Since magnesium reacts completely with oxygen, it is the limiting reactant in the reaction. Hence, we can use the number of moles of magnesium to get the mass of MgO produced:
     moles of magnesium = 14.7g / 24.305g mol-1
                                       = 0.6048 mol

     mass of MgO = 0.6048mol Mg(2 mol MgO/2mol Mg)(40.3044g MgO/1 mol MgO) 
                           = 24.376g MgO

We can now solve for the percentage of magnesium:
     % Mg = (14.7g Mg / 24.376g MgO)*100% = 60.3%

We also use the number of moles of magnesium to get the mass of oxygen consumed in the reaction:
     mass of O2 =  0.6048 mol Mg (1mol O2 / 2mol Mg) (31.998g / 1mol O2) 
                        = 9.676g

The percentage of oxygen is therefore
     % O2 = (9.676g O2 / 24.376g MgO)*100%
               = 39.7%
Notice that we can just subtract the magnesium's percentage from 100% to get 
     % O2 = 100% - 60.3% = 39.7%
You might be interested in
2) Show the calculation of Kc for the following reaction if an initial reaction mixture of 0.800 mole of CO and 2.40 mole of H2
nadezda [96]

Answer:

Kc = 3.90

Explanation:

CO reacts with H_2 to form CH_4 and H_2O. balanced reaction is:

CO(g) + 3H_2 (g) \leftrightharpoons CH_4(g)  +  H_2O(g)

No. of moles of CO = 0.800 mol

No. of moles of H_2 = 2.40 mol

Volume = 8.00 L

Concentration = \frac{Moles}{Volume\ in\ L}

Concentration of CO = \frac{0.800}{8.00} = 0.100\ mol/L

Concentration of H_2 = \frac{2.40}{8.00} = 0.300\ mol/L

                 CO(g) + 3H_2 (g) \leftrightharpoons CH_4(g)  +  H_2O(g)

Initial            0.100      0.300             0   0

equi.            0.100 -x    0.300 - 3x     x    x

It is given that,

at equilibrium H_2O (x) = 0.309/8.00 = 0.0386 M

So, at equilibrium CO = 0.100 - 0.0386 = 0.0614 M

At equilibrium H_2 = 0.300 - 0.0386 × 3 = 0.184 M

At equilibrium CH_4 = 0.0386 M

Kc=\frac{[H_2O][CH_4]}{[CO][H_2]^3}

Kc=\frac{0.0386 \times 0.0386}{(0.184)^3 \times 0.0614} =3.90

8 0
3 years ago
In 1803, John Dalton proposed an atomic theory. Three critical pieces of this theory included the following:
ValentinkaMS [17]
D. Proton, electron, neutron.
6 0
2 years ago
Which description best characterizes the motion of particles in a solid
bixtya [17]
<span>The movement of particles within a solid is extremely slow when compared to that of a gas. It is also significantly slower in movement than that of the movement found within the particles of liquid. The more movement present and the faster the movement of the particles the more space will be present between each particle. This causes the material to spread out as they become less densely packed within a solid material.</span>
8 0
3 years ago
Read 2 more answers
When one form of energy is transformed into another no energy is destroyed in the process?
katrin2010 [14]
Yes that is true, when energy is transformed energy is not destroyed.
8 0
2 years ago
The destructive force of waves is not felt while they are out at sea, in the open ocean, but it is felt when they do what?
PIT_PIT [208]

Answer: Come Onshore

Explanation:

Sea waves are harmless when present at Sea. However, it becomes DESTRUCTIVE as it travels to the land surface.

Its effects include the sweeping off (erosion) of features, BENEFICIAL soil organisms and the transport of sand and sediment along coastal areas which might include farms, residential houses etc.

Thus, the effects of Sea waves ONSHORE affects the following: agricultural activities

Domestic activities

Environmental balance etc.

6 0
3 years ago
Read 2 more answers
Other questions:
  • In each row check off the boxes that apply to the highlighted reactant. reaction The highlighted reactant acts as a... (check al
    15·1 answer
  • What is a necessary reactant for glycolytic, or anaerobic, catabolism to proceed?
    14·1 answer
  • Seasonal variation on earth is due to the
    7·1 answer
  • if the mole fractio of NaCl in an aqueous solution is 0.0927, what is the wt/wt% (percent by mass) of NaCl
    12·1 answer
  • What is the maximum mass of s8 that can be produced by combining 89.0 g of each reactant?
    11·1 answer
  • How many electrons would be transferred in either a voltaic or electrolytic cell that uses the following half reactions
    13·1 answer
  • How many moles of ammonium carbonate are needed to decompose in order to produce 6.52g of carbon dioxide? Ammonium oxide is the
    14·1 answer
  • What particles flow through the circuit attached to a battery
    5·2 answers
  • Which example is a mixture of a gas dissolved in a liquid?
    7·2 answers
  • Which of the following is an
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!