Answer:
Percent yield = 99.6%
Theoretical yield = 25.5 g
Explanation:
Given data:
Mass of copper = 12.5 g
Mass of copper(II) chloride produced = 25.4 g
Theoretical yield = ?
Percent yield = ?
Solution:
Chemical equation:
Cu + Cl₂ → CuCl₂
Number of moles of copper:
Number of moles = mass/molar mass
Number of moles = 12.5 g / 63.5 g/mol
Number of moles = 0.19 mol
Now we will compare the moles of copper and copper chloride.
Cu : CuCl₂
1 : 1
0.19 : 0.19
Mass of CuCl₂: Theoretical yield
Mass = number of moles × molar mass
Mass = 0.19 mol × 134.45 g/mol
Mass = 25.5 g
Percent yield:
Percent yield = (actual yield / theoretical yield )×100
Percent yield = ( 25.4 g/ 25.5 g) ×100
Percent yield = 99.6%
Applying a force for a longer time increases the change in
(select all that apply)
Weight
Gravity
Velocity
Mass
Momentum
Answer:
velocity and momentum
Explanation:
as you exert force, the object accelerates, hence, its velocity increases.
since momentum is mass times velocity, the momentum increases too
Please be reminded, this answer may not be 100% correct
When the force should be applied for a long time so it increases the change in velocity and momentum
What is velocity and momentum?The momentum of the object should be equivalent to the object mass times with the object velocity
Here
p = mv
Here p means momentum
m means mass
v means velocity
Here the momentum should be directly proportional to the mass of the object and for the velocity of the object also.
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23) What is the volume of 2.454 x 1024 atoms of nitrogen gas at STP?
[a] 1.096 x 1023 L
[b] 6.595 x 1048 L
[c] 2.241 x 1026 L
[d] 91.31L
Answer:
d) V = 91.3 L
Explanation:
Given data:
Volume of nitrogen = ?
Temperature = standard = 273.15 K
Pressure = standard = 1 atm
Number of atoms of nitrogen = 2.454×10²⁴ atoms
Solution:
First of all we will calculate the number of moles of nitrogen by using Avogadro number.
1 mole = 6.022×10²³ atoms
2.454×10²⁴ atoms × 1 mol / 6.022×10²³ atoms
0.407×10¹ mol
4.07 mol
Volume of nitrogen:
PV = nRT
1 atm × V = 4.07 mol ×0.0821 atm.L /mol.K ×273.15 K
V = 91.3 atm.L /1 atm
V = 91.3 L
Which of the following correctly shows the relationship, in terms of number of particles, of the three substances?
A. 1 mole of water < 1 mole of helium < 1 mole of aluminum
B. 1 mole of aluminum = 1 mole of helium = 1 mole of water
C. 1 mole of aluminum < 1 mole of helium < 1 mole of water
D. 1 mole of helium < 1 mole of aluminum < 1 mole of water
The correct option which shows the relation between particles of the three substances is 1 mole of aluminum = 1 mole of helium = 1 mole of water.
What is a particle?
A particle is a small part of matter.
The term refers to particles of all sizes, ranging from subatomic particles like electrons to visible particles like dust particles floating in sunlight.
The relationship of a number of particles of the substance can be calculated by Avogadro's law
Thus, the correct option is B. 1 mole of aluminum = 1 mole of helium = 1 mole of water
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Methane is a gas that easily catches fire. This statement is describing a _____.
Answer:
I believe the answer would be chemical reaction.
can someone show me the work on 3-8?
3. 426 g
4. 413.4 g
5. 1328.4 g
6. 192.4 g
7. 106.4 g
8. 0.617 mol
Further explanationGiven
moles and mass
Required
Conversion mole to gram
Solution
General formula :
mole (n) = mass : MW
3. 6 moles Cl₂(MW = 71 g/mol) :
= 6 moles x 71 g/mol
= 426 g
4. 5.3 moles CaF₂(MW=78 g/mol)
= 5.3 mol x 78 g/mol
= 413.4 g
5. 8.2 moles FeCl₃(MW=162 g/mol)
= 8.2 mol x 162
= 1328.4 g
6. 2.6 moles Li₂CO₃(MW=74 g/mol)
= 2.6 mol x 74 g/mol
= 192.4 g
7. 3.8 moles N₂(MW=28 g/mol)
= 3.8 mol x 28 g/mol
= 106.4 g
8. 100 g FeCl₃(MW=162 g/mol)
= 100 g : 162 g/mol
= 0.617 mol
1) A chemist was deciding what chemical to use in a handwarmer. She studies 2 compounds. One is a nonpolar covalent compound that is safe and nontoxic. The other is an ionic compound. It is poisonous if ingested. What tests could she do to tell them apart? Give two possible observations or tests she can run to verify the substance. Which substance would you use to make the handwarmer and why?
Answer: Water dissolves nonpolar covalent substances.
The Nonpolar substance which is nontoxic is better material to be used in making the hand warmers.
A hand warmer is a little substance which can be put in between the hands in order to heat them up. This is particularly of necessity in the cold weather when the hands are cold.
The chemist can distinguish the polar substance from the nonpolar substance by dissolving each substance in water. The polar substance will dissolve in water while the non polar substance will not dissolve in water.
Secondly, the two substances can be heated and the melting temperatures are observed. The ionic substance will melt at a much higher temperature than the nonpolar substance. The Nonpolar substance which is nontoxic is a better material to be used in making the hand warmers.
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Which process is an example of a chemical change?
a. cooking a steak
b. chopping a tree
c. heating a cup of tea
d. drying clothes in the dryer
Answer:
A is the closest thing. You change the composition of the steak. You don't in any of the others.
Explanation:
Usually when you cook something, you are doing something to the composition of the object being cooked. A steak might not be obvious, but boiling an egg should be.
Chopping a tree is something physical. You are removing mass in such a way that the tree will fall. There's nothing chemical about that.
Heating a cup of tea looks like it might be chemical. After all steam is sometimes given off which looks like it is chemical. It's not. The water in the tea is just changing phase.
Drying clothes in a dryer. Again, this looks like something might have changed. After all the mass of the clothes just became less. But all you are doing is separating two masses (leaving one of them behind).
Which of the following reactions would have a decrease in entropy?
A. 2H20(g) → 2H2(g) + O2(9)
B. 2503(9) ► 2502(g) + O2(g)
C. 2NH3(9) ► N2(g) + 3H2(9)
D. 2NO2(g) → N204(9)
Answer:
D. 2NO2(g) → N204(9)
Explanation:
A p e x
2NO[tex]_2[/tex](g) → N[tex]_2[/tex]O[tex]_4[/tex](g) reactions would have a decrease in entropy. Therefore, the correct option is option D.
What is entropy?Entropy is a measureable physical characteristic and a scientific notion that is frequently connected to a condition of disorder, unpredictability, or uncertainty. From classical thermodynamic, where it was originally recognized, towards the microscopic explanation of nature within statistical physics, the name and concept are employed in a variety of disciplines.
It has numerous applications in physics and chemistry, biological systems and how they relate to life, cosmology, economics, society, weather science, and information systems, especially the exchange of information. 2NO[tex]_2[/tex](g) → N[tex]_2[/tex]O[tex]_4[/tex](g) reactions would have a decrease in entropy.
Therefore, the correct option is option D.
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how many moles are represented by 3.01x10^23 helium atoms
a. 1 mole
b. 0.50 moles
c. 0.75 moles
d. 5 moles
Answer:
b. 0.50 moles
Explanation:
To solve this problem we use Avogadro's number (6.023x10²³ atoms/mol).
By dividing the number of atoms (or molecules) by that number, we can calculate how many moles they represent.
3.01x10²³ atoms ÷ 6.023x10²³ atoms/mol = 0.50 molesSo the answer is option b. 0.50 moles.
What kind of cell has a nonspontaneous voltage?
An electrolytic cell
A dry cell
A wet cell
A voltaic cell
Answer:
dry cell
Explanation:
because it stops when salt distribution becomes equal as bridge is not added
Answer:
a
Explanation:
a p e x :)
LOTS OF POINTS WILL GIVE BRAINLIEST!!
Plot a graph of relative atomic mass against boiling point for the
elements in Group 0.
Answer:
I found this, hope it works
Explanation:
As the mass of the noble elements increases the boiling point gradually decreases and the graph of the two parameters is a straight line graph with downward slope.
What is an element?It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
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Is your breath becoming visible on a cold day a physical change
Answer:
no
Explanation:
it is condensation not physical change
Which of the following is a monoatomic molecule? *
Phosphorus
Sulphur
Neon
chlorine
phosphorus
Explanation:
other are diatomic
Cl2
S2
Ne2
HELLLPPPPPPPPPP
Match each substance with either acid or base.
Lemon juice:
Baking soda:
Ammonia:
Vinegar:
PLZ DON'T GUESS THE ANSWER
Answer:
Lemon Juice - Acid
Baking Soda - Base
Ammonia - Base
Vinegar - Acid
What coefficient should be placed before 02?
2S+ __02 → 2S03
Explanation:
[tex]\tt{2S+6O_2\implies{2SO_3} }[/tex]
Please help me 14 points!
Answer:
2
Explanation:
how many atoms are in 2.45 moles of hydrogen
Answer:
There are 1.4754246675000002e+24 atoms of Hydrogen within the measurement of 2.45 moles of hydrogen!
Explanation:
Most polyatomic ions are cations.
TRUE
FALSE
The answer is False.
How do you measure density?
Density over mass
Mass over volume
Volume over density
Mass over density
Answer:
Mass over Volume........
*
Why does the mass of a substance remain the same after a chemical reaction?
What is the molar mass of MgI2
Answer:
278.1g/mol
Explanation:
To find the molar mass of the given compound, we must know the atomic mass of the elements within the compound.
Atomic mass of Mg = 24.3g/mol
Atomic mass of I = 126.9g/mol
So;
Molar mass = 24.3 + 2(126.9) = 278.1g/mol
The molar mass of the compound is 278.1g/mol
why is hardness important in identifying minerals
how do you find out which molecule out of two is more polar
Answer:
Check the electronegativities of the atoms involved in each bond. The greatest difference in electronegativity will correspond to the most polar bond.
This biome has extremely cold winters and short, mild summers. It has no trees, only low-growing plants with short root systems because of its frozen soil
called the permafrost. It is covered by snow for most of the year. Animals that live here must have wide paws or hooves to walk through the frozen mushy.
soil. This biome is known as the_________
A. Tropical rainforest
B. Taiga
C. Deciduous Forest
D. Desert
E. Grassland
F. Tundra
Making Sense
1. School bus drivers are extra careful when they cross railroad tracks. They stop before they cross railroad tracks to be sure that there is no
train coming. Yet, trains typically move more slowly through towns than cars do. If trains usually move more slowly than cars, why can
they do more damage if they hit something in their path?
=
2
11
B
1
GO
III
un
III
X2
Saved January 15, 2021 07:35:00 PM
Answer: I think that trains move faster then cars! Buttt, The trains are much stronger and bigger, then cars or trucks. Even if they move slowly they can still crush something smaller then them.
Explanation: ( didnt really understand the question, but i tried)
you can't change or add________!you can only put number in front of the elements or compound.
If you mix aqueous solutions of potassium nitrate and iron(II)sulfate what will be the precipitate, if there is one at all?
Answer:
No one will precipitated because these all are soluble in water
Explanation:
2KNO3 + FeSO4 -----> K2SO4 + Fe(NO3)2
How many moles and atoms are there in 60 grams of Calcium?
Answer:
The moles present in 60 g of calcium are 1.5 moles.
Answer:
In 60 grams there are 1,5 mols
Explanation:
Describe the relationship between frequency and wavelength in your own words
how many moles of oxygen atoms are in one mole of the molecule Ca5(PO4)3OH?
Answer:
13
Explanation:
There are 13 moles O in a mole of Ca5(PO4)3OH because there are 13 oxygen atoms in every molecule of Ca5(PO4)3OH. Convert moles oxygen to number of atoms of oxygen. One mole is 6.022*10^23, so your conversion factor would be 6.022*10^23 atoms O/mol O.