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
Mamont248 [21]
3 years ago
9

During an investigation, a student burns magnesium to form magnesium oxide. The starting mass of magnesium is measured as 21.3 g

.
2Mg( s)+02( 8) - 2MgO( s)
If the student recovers 30.2 g of magnesium oxide, what is the percent yield? (atomic mass of magnesium = 24.3 amu)
Chemistry
1 answer:
enot [183]3 years ago
3 0

Answer:

Percentage yield = 85.2%

Explanation:

Given data:

Mass of Mg = 21.3 g

Actual yield of MgO = 30.2 g

Percentage yield = ?

Solution:

Chemical equation:

2Mg + O₂ → 2MgO

Number of moles of Mg = mass/molar mass

Number of moles of Mg = 21.3 g / 24.3 g/mol

Number of moles of Mg = 0.88 mol

Now we will compare the moles of MgO with Mg.

                 Mg           :               MgO

                 2               :               2

                0.88             :             0.88

Mass of MgO:           

Mass of MgO= moles × molar mass

Mass of MgO= 0.88 mol × 40.3g/mol

Mass of MgO =  35.46 g

Actual yield of MgO = 30.2 g

Percentage yield:

Percentage yield = Actual yield/theoretical yield × 100

Percentage yield = 30.2 g/ 35.46 g × 100

Percentage yield = 85.2%

You might be interested in
QUESTION 3 (a) Ammonium sulphate, (NH),50, is a soluble salt and it is used in agriculture as fertiliser. 5 g of ammonium sulpha
nataly862011 [7]

Answer:

The equation: (NH₄)₂SO₄ = 2NH4(+) + SO4(-2)

The number of moles = 5 g / 132.14 g/mol = 0.038 mol

The number of molecules = 0.038 X 6.022x10^23 = 2.29x10^23

the number of positive ions present in the ammonium sulphate solution:

2 positive ions for every 1 molecule of (NH₄)₂SO₄

so 2 x 2.29x10^23 = 4.58x10^23

the number of negative ions present in the ammonium sulphate solution

1 negative ion for every 1 molecule of (NH₄)₂SO₄

so 1 x 2.29x10^23 = 2.29x10^23

the total number of ions present in the ammonium sulphate solution​

4.58x10^23 + 2.29x10^23 = 6.87x10^23

4 0
3 years ago
A gas sample occupies 350.0 mL at 546 mm Hg. What volume does the gas occupy at 652 mm Hg?​
leva [86]

Answer:

293.1 mL.

Explanation:

  • Boyle's law states that: at a constant temperature the pressure of a given mass of an ideal gas is inversely proportional to its volume.
  • It can be expressed as: <em>P₁V₁ = P₂V₂,</em>

P₁ = 546.0 mm Hg, V₁ = 350.0 mL.

P₂ = 652.0 mm Hg, V₂ = ??? mL.

<em>∴ V₂ = (P₁V₁)/(P₂)</em> = (546.0 mm Hg)(350.0 mL) / (652.0 mm Hg) = <em>293.1 mL.</em>

8 0
3 years ago
With circulation, the heart provides your body with:
Ivanshal [37]
<h3>Answer:  D) all of the above</h3>

Explanation:

The lungs pump oxygen in and carbon dioxide out, which goes through the blood stream to help with the cell's energy needs.

Nutrients pass through the blood stream as well. The nutrients start with the digestive system (mouth, esophagus, stomach, small intestine) before going into the blood stream. The nutrients are building blocks to help make new cells when old ones die off.

When those cells die off, the body sheds them like dead skin, but internal dead cells are passed off as waste. This waste and other byproducts the body doesn't need passes through the blood stream as well.

In short, the blood stream is basically the highway to help get desired materials (eg: oxygen and nutrients) and get rid of waste (eg: carbon dioxide and other unwanted byproducts or dead cell material)

So that's why the answer includes A, B and C.

8 0
3 years ago
A/an _______ is the smallest unit of matter that has the characteristics of a chemical element.
julsineya [31]

Answer:

The answer is atom.

Explanation:

7 0
2 years ago
Read 2 more answers
Is carbon dioxide a compound, element,or a mixture? wat about air wat is it
sveta [45]
Carbon dioxide is a compound. Oxygen is an element. A compound is 2 or more elements chemically combined. An element is a pure substance. A mixture is combining two or more different compounds/elements.
6 0
2 years ago
Other questions:
  • Consider the following equilibrium:H2CO3(aq) + H2O(l) H3O+(aq) + HCO3-1(aq).What is the correct equilibrium expression?
    14·1 answer
  • Carbonates react with acids in order to form salt,water, snd carbon dioxide gas. When 50.0 grams of calcium carbonate are reacte
    13·1 answer
  • Rosalinda wants to calculate the mass of Earth using Kepler’s laws or Newton’s universal law of gravitation.Which data would all
    12·2 answers
  • The enzyme amylase will affect the breakdown of carbohydrates, but it will not affect the breakdown of proteins. The ability of
    10·1 answer
  • Plz help me.....im new here
    14·2 answers
  • Differentiate between homogenous and heterogeneous catalysis​
    13·1 answer
  • Sorry for asking for too much but me needs helppppp
    12·2 answers
  • If a negatively charged ion is more concentrated outside the cell, the forces required to balance the chemical gradient would be
    8·1 answer
  • 1. Except for special cases such as peroxides, oxygen has an oxidation number of _______ in compounds. A. +2 B. –1 C. +1 D. –2
    6·1 answer
  • How many grams are in 4 5 moles of sodium fluoride naf
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!