The equation is balanced. There are 4 aluminium atoms and 6 oxygen atoms on each side.
How many moles are in 3.4 x 10-7 grams of Silicon dioxide, SiO2?
Answer:
Number of moles = 0.057 × 10⁻⁷ mol
Explanation:
Given data:
Mass of SiO₂ = 3.4 × 10⁻⁷ g
Number of moles = ?
Solution:
Number of moles = mass/molar mass
Molar mass of SiO₂ = 60 g/mol
by putting values,
Number of moles = 3.4 × 10⁻⁷ g / 60 g/mol
Number of moles = 0.057 × 10⁻⁷ mol
Which is a pure substance?
They are chemically bonded together.
They can be classified as pure substances.
They have fixed ratios between their components.
They can be separated by physical processes.
Answer: C. They have fixed ratios between their components.
Heelllpp ASAP .............
Answer is
Chloromethane
Explanation: because c stand for carbon an the h stands for hydrogen and ci stands for
Chemical ionization
Describe how the periodic
table is organized and how
that organization increases
its usefulness (hint: think
about how the position of an
element in the table matters)
Answer:
Elements in the periodic table are arranged according to the increasing atomic number.
We can predict the chemical properties of an element by looking at it's position in the periodic table.
Rosie balanced the equation below with the lowest coefficients, however she made a mistake.
2 AgCl + 2 Mg(NO3)2 --> 1 AgNO3 + 2 MgCl2
What was her error and what should the correct answer be?
Answer:
2 AgCl + Mg(NO3)2 --> 2AgNO3 + MgCl2
Explanation:
This is balanced equation
In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?
A. one
B. two
C. three
D. four
E. none
Answer:
E.none
Explanation:
because the bonds join with each other and no lone pair is left
What is the concentration in mol L-l of a 12% solution of tetrahydrate magnesium chloride (MgCl2)?
Mg = 24.31 g mol-1
Cl = 35.45 g mol-1
H = 1.01 g mol-1
O = 16.00 g mol-1
The concentration in mol L-l (M) = 0.717
Further explanationGiven
12% solution of tetrahydrate magnesium chloride (MgCl₂)
Required
The concentration
Solution
Tetrahydrate magnesium chloride (MgCl₂)⇒MgCl₂.4H₂O
MW = Ar Mg+2. Ar Cl+8. Ar H + 4. Ar O
MW=24.31 + 2 x 35.45 + 8 x 1.01 + 4 x 16
MW=24.31+70.9+8.08+64
MW=167.29 g/mol
12% solution = 12 % m/v = 12 g in 100 ml solution
For 1 L solution :
[tex]\tt \dfrac{1}{0.1}\times 12~g=120~g[/tex]
The concentration in g/L = 120 g/L
Convert grams to moles :
[tex]\tt mol=\dfrac{120}{167.29}=0.717[/tex]
name the group and period of an element having atomic number 21
Answer:
The element in question here is Scandium, with an atomic number of 21. It is situated in Group 3 and Period 4 of the Periodic Table.
Explanation:
Hope this helped!
Suppose 3.20 g of copper are reacted with excess nitric acid according to the given equation, and 6.32 g Cu(NO3)2 product are obtained.
Cu(s) + 4 HNO3 (aq) --> Cu(NO3)2 (aq) + 2 NO2 (g) + 2 H2O(l)
What is the theoretical yield of Cu(NO3)2? In g
What is the percent yield of Cu(NO3)2? In %
Answer:
1. 9.45 g
2. 66.9%
Explanation:
The balanced equation for the reaction is given below:
Cu(s) + 4HNO3(aq) —> Cu(NO3)2(aq) + 2NO2(g) + 2 H2O(l)
Next, we shall determine the mass of Cu that reacted and the mass of Cu(NO3)2 produced from the balanced equation. This can be obtained as follow:
Molar mass of Cu = 63.5 g/mol
Mass of Cu from the balanced equation
= 1 × 63.5 = 63.5 g
Molar mass of Cu(NO3)2 = 63.5 + 2[14 + (3×16)]
= 63.5 + 2[14 + 48]
= 63.5 + 2[62]
= 63.5 + 124
= 187.5 g/mol
Mass of Cu(NO3)2 from the balanced equation = 1 × 187.5 = 187.5 g
Summary:
From the balanced equation above,
63.5 g of Cu reacted to produce 187.5 g of Cu(NO3)2.
1. Determination of the theoretical yield of Cu(NO3)2. This can be obtained as follow:
From the balanced equation above,
63.5 g of Cu reacted to produce 187.5 g of Cu(NO3)2.
Therefore, 3.20 g of Cu will react to produce = (3.20 × 187.5) / 63.5 = 9.45 g of Cu(NO3)2.
Thus, the theoretical yield of Cu(NO3)2 is 9.45 g.
2. Determination of the percentage yield of Cu(NO3)2.
Actual yield of Cu(NO3)2 = 6.32 g
Theoretical yield of Cu(NO3)2 = 9.45 g.
Percentage of the Cu(NO3)2 =?
Percentage yield = Actual yield /Theoretical yield × 100
Percentage yield of Cu(NO3)2 = 6.32/9.45 × 100
Percentage yield of Cu(NO3)2 = 66.9%
The theoretical yield of Cu(NO₃)₂ is 9.445 g
The percent yield of Cu(NO₃)₂ is 66.91%
From the question.
We are to determine the theoretical yield of Cu(NO₃)₂,
First and foremost, we will write the balanced chemical equation for the reaction properly
The balanced chemical equation for the reaction is
Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O(l)
This means
1 mole of Cu will react with 4 moles of HNO₃ to produce 1 mole of Cu(NO₃)₂, 2 moles of NO₂ and 2 moles of H₂O
To determine the theoretical yield of Cu(NO₃)₂,
First, we will determine the number of moles of Cu that reacted
Mass of Cu = 3.20 g
Molar mass of Cu = 63.546 g/mol
From the formula
[tex]Number\ of\ moles =\frac{Mass}{Molar\ mass}[/tex]
∴ Number of moles of Cu = [tex]\frac{3.20}{63.546}[/tex]
Number of moles of Cu present = 0.050357 moles
The number of moles of Cu that reacted is 0.050357 moles
Since,
1 mole of Cu will react with 4 moles of HNO₃ to produce 1 mole of Cu(NO₃)₂
Then,
0.050357 moles of Cu will react with 0.201428 moles of HNO₃ to produce 0.050357 moles of Cu(NO₃)₂
∴ 0.050357 moles of Cu(NO₃)₂ will be produced during reaction
Now, for the theoretical yield of Cu(NO₃)₂
From the formula
Mass = Number of moles × Molar mass
Molar mass of Cu(NO₃)₂ = 187.56 g/mol
∴ Theoretical yield of Cu(NO₃)₂ = 0.050357 × 187.56
Theoretical yield of Cu(NO₃)₂ = 9.445 g
Hence, the theoretical yield of Cu(NO₃)₂ is 9.445 g
For the percent yield of Cu(NO₃)₂
[tex]Percent \ yield = \frac{Actual \ yield}{Theoretical \ yield } \times 100 \%[/tex]
From the question
Actual yield = 6.32 g
But,
Theoretical yield = 9.445 g
∴ Percent yield of Cu(NO₃)₂ = [tex]\frac{6.32}{9.445} \times 100\%[/tex]
Percent yield of Cu(NO₃)₂ = [tex]\frac{632}{9.445}\%[/tex]
Percent yield of Cu(NO₃)₂ = 66.91%
Hence, the percent yield of Cu(NO₃)₂ is 66.91%
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why do chemist synthesize polymers in the lab?
The reason why chemists synthesize polymers in the lab is;
because of the need to perform and observe the results of a variety of synthesized polymer reactions and to predict when a reaction will happen.
Polymers are simply defined as a substance or material made up of long repeating chemical chains of molecules.
Now, polymer synthesis is simply called polymerization and it is the process by which smaller molecules called monomers undergo covalent bonding to form a longer polymer chain.
Now, from the definition above, the reason why chemists synthesize polymers in the lab is because of the need to perform and observe the results of a variety of synthesized polymer reactions and to predict when a reaction will happen.
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Which material would get electrons from the source to the load the fastest
Answer:
Copper
Explanation:
Because copper conducts a lot of electricity, and gets the most electrons
What is the definition of a chemical bond?
(A) a mutual repulsion between the nuclei and electrons in two different atoms
(B) a mutual attraction between the nuclei and electrons in two different atoms
(C) a mutual attraction between the nuclei and electrons in a single atom
(D) a mutual repulsion between the nuclei and electrons in a single atom
Answer:
B
Explanation:
bonding is a process of two different atoms sharing electrons for stability and these electrons are attracted by one atom losing it's electrons to another
An atom has a mass number of 9 and 5 neutrons. What is its atomic number? A 19 B. 14 O c.4 D. 11 SN
Answer:
[tex]\boxed {\boxed {\sf C. \ 4}}[/tex]
Explanation:
First, define some important terms.
Mass number: the sum of the nucleons (protons and neutrons) Atomic number: the number of protonsWe know the mass number is 9. So, the sum of protons and neutrons is 9.
[tex]mass \ number =9[/tex][tex]protons + neutrons = 9[/tex]We also know the atoms has 5 neutrons. Therefore, the rest must be protons.
[tex]protons + 5 \ neutrons =9[/tex]Subtract the 5 neutrons from the overall mass number of 9.
[tex]protons = 9- 5 \ neutrons \\[/tex][tex]protons=4[/tex]There are 4 protons, so the atomic number is also 4. This atom is beryllium.
15
Question 56 (1 point)
What is the name of the compound with the chemical formula SnSnO3?
Answer: sodium sulfite
Explanation:
Which electron dot diagram represents H2?
Answer:
H:H
Explanation:
Choose all the right answers.
Why do all machines lose some energy while they operate?
They run out of fuel.
Some heat radiates out.
Moving parts cause friction.
High pressure gases move the piston.
Answer:
They run out of fuel
Some heat radiates out
High pressure gases move the piston
Don’t know need the anwser !!DUE MONDAY!!
Answer: The distance is slightly less than 3.5 m
Explanation: assuming wall and target are the same thing, and the bullet has constant velocity, the bullet will travel 7 m in half a second, so half that distance is 3.5 m.
In reality, the bullet is decelerating (at an unknown rate) so the distance is slightly less than 3.5 m.
There is also a vertical velocity component, which means it hits the target/wall at an angle. The trajectory is such that it hits the wall above the shooter because the ricochet hits at ~the level at which it left the firearm.
If the wall was absent, the bullet would have described a parabola which brough it back to the initial level after 7m. This could be calculated, but it means that the actual distance between the shooter and the wall is slightly less than 3.5 m
In addition, the collision with the wall is not 100% elastic, so the velocity aftercthe ricochetvis further reduced.
A calculation would be complex because these confounding factors are not completely independent of each other, but all reduce the average velocity and therefore the distance.
Therefore it is only possible to say that the distance was somewhat less than 3.5 m
17. What is the correct empirical formula for H4C408?
A
H2C204
B HCO2
C
HCO4
D
H2C202
Answer:
B
Explanation:
by simlfying it you get HCO2
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(
)O2 → (
)O3
Answer:
3
2
Explanation:
3O2 => 2O3
the equation is balancing
What happens to a rock formation that undergoes a repeated and frequent freeze and thaw cycle of water?
Answer:
Water from melting snow or rainfall infiltrates into cracks in rocks. ... As this process of freezing and thawing happens repeatedly, the rock begins to weaken and eventually breaks apart into angular fragments.
Explanation:
Water melting from snow or rainfall which infiltrates into cracks in rocks, this is repeated process of freezing and thawing, the rock begins to weaken and eventually breaks apart into angular fragments.
What are types of rock layers ?A rock can be formed due to the aggregation of mineral constituents in the earth’s crust and it can be classified is based on different factors like Geological classification, Physical classification, Chemical classification.
Geological classification can be either Sedimentary rock formed by the deposition of sediments by the weathering of pre-existing rocks and it can be carried out by various agents like water, wind, gravity, etc.
Igneous rocks formed by the solidification of magma below the earth’s surface which is held together below the earth’s surface and unable to descend, when these magma cools down and solidifies into igneous rocks.
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Which of the following would be most useful in trying to obtain procedural information to replicate an experiment previously published?
Answer: Peer-reviewed journal article is the most useful because the information in them had been carefully scrutinized and aproved by people who are experts in that particular field.
Ricardo is working on a refrigeration system and needs to know the fluid pressure of a water tank. He knows that the tank is 12 in long, 12 in wide, and 12 in high, and holds 1 cubic foot of water. He also knows that the weight of 1 cubic foot of water is approximately 62.4 lb.
What's the fluid pressure?
Answer:
I also have this question but see the 69 page of ur question book
PLEASE HELP WILL GIVE BRAINLIEST
Answer: B
We use stoichiometric amounts of P4 and PH3
NO.9) It's actual yield
A compound has an empirical formula of
CHN. What is its molecular formula, if its
molar mass is 135.13 g/mol?
(C=12.01 amu, H=1.008 amu, N=14.01)
A
B
C5H5N5
CG HONG
Explanation:
Given -
molar mass = 135.13 g/mol
To Find -
molecular formulaSolution:
we know that -
molecular mass = n × empirical massSo,
Here empirical mass =
12.01 + 1.008 + 14.01 = 27.028
Then,
135.13 = n × 27.028
n = 4.99 ≈ 5
We know that,
molecular formula = n × empirical formulaThen,
molecular formula = 5(CHN)
= C₅H₅N₅
Therefore,
Option A is correct✔
What 3 particles make up an atom and what is their electrical charge?
What is a "mole" in chemistry?
Answer:
Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other
Answer:
Mole, also spelled mol, in chemistry, a standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.
Explanation:
You want to measure the volume of a gold bracelet. For this purpose, a specimen with 20 mL of water is available; when inserting the bracelet, the water level rises to 25 mL. If the density of gold is 19300 Kg/m3. What will be the mass of the bracelet?
Answer:
volume of bracelet is 5cm3
mass is 0.0965Kg
Explanation:
1ml = 1cm3
1m3 = 1000000cm3
0.000005m3
Mass = volume*density
19300 Kg/m3 * 0.000005m3 = 0.0965Kg
Two models of the same compound are shown.
On the left labeled Model A 2 large overlapping black spheres with 3 small blue spheres overlapping the rear black sphere and 2 medium red spheres overlapping the front black sphere. One of the red spheres has a small blue sphere overlapping it. On the right labeled Model B 2 C's connected by a black line. The C on the left has 3 H's attached by 1 black line each and the C on the right has 2 Os attached to it. The top O is attached by 2 black lines and the bottom O by 1 black line. The bottom O also has an H attached to it by 1 black line.
In what way is Model A better than Model B?
Model A shows the types of elements in the compound, but Model B does not.
Model A shows the total number of atoms in the molecule, but Model B does not.
Model A shows the three-dimensional shape of the molecule, but Model B does not.
Model A shows the number of atoms of each element in the molecule, but Model B does not.
Answer: C. Model A shows the three-dimensional shape of the molecule, but Model B does not.
Explanation:
i took the test and it makes the most sence for the modeles.
When the volume of a gas is
changed from 3.6 L to 15.5 L, the
temperature will change from
°C to 87°C.
Assume that the number of moles and the
pressure remain constant.
Be sure to notice that temperatures are
given in °C!
Initial temperature = -189.4 °C
Further explanationGiven
the volume of a gas is changed from 3.6 L to 15.5 L
final temperature = 87 °C = 87+ 273 = 360 K
Required
initial temperature
Solution
Charles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature
[tex]\tt \dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}[/tex]
[tex]\tt T_1=\dfrac{V_1.T_2}{V_2}\\\\T_1=\dfrac{3.6\times 360}{15.5}\\\\T_1=83.6~K=-189.4^oC[/tex]
Robert makes a glass of tea and takes it outside with him. While outside, the thermal energy within the glass of tea is transferred to its surroundings. Based on this information, what else is happening within the glass of tea?
A.
The kinetic energy of the particles is increasing and the temperature is decreasing.
B.
The kinetic energy of the particles is increasing and the temperature is increasing.
C.
The kinetic energy of the particles is decreasing and the temperature is increasing.
D.
The kinetic energy of the particles is decreasing and the temperature is decreasing.
Answer:
A
Explanation:
i had answer it and it was A