Answer:
40
Explanation:
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]
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
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.
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!
What 3 particles make up an atom and what is their electrical charge?
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
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
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]
Read the word equation: “Propane gas plus oxygen gas produces __________.”
b) Convert the word equation to a chemical equation and complete the reaction. Be sure to balance
the chemical equation.
c) Record the balanced chemical equation on the Student Worksheet.
Answer:
Propane gas plus oxygen gas produces water and carbon dioxide.
Explanation:
This is the initial chemical equation: C3H8 + O2 = CO2 + H2O
This is the balanced chemical equation: C3H8 + 5 O2 = 3 CO2 + 4 H2O
C3H8 + O2 → CO2 + H2O
However, the above equation is not balanced. To balance it, we make use of coefficients to make the number of atoms of each element equal. The balanced equation is as follows:C3H8 + 5O2 → 3CO2 + 4H2O
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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
Heelllpp ASAP .............
Answer is
Chloromethane
Explanation: because c stand for carbon an the h stands for hydrogen and ci stands for
Chemical ionization
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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PLEASE HELP WILL GIVE BRAINLIEST
Answer: B
We use stoichiometric amounts of P4 and PH3
NO.9) It's actual yield
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
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
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
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
What is the mass percent of oxygen (0) in SO2?
32.1 g
A.
x 100%
16.0 g + 16.0 g
(16.0 g +16g)(6.02 x 1023)
B.
100 g
16.0 g
x 100%
(32.1 g + 16.0 g + 16.0 g)
D.
(16.0 g + 16.0 g)
X 100%
(32.1 g + 16.0 g + 16.0 g)
SUIRMIT
Answer:
D. (16.0 g + 16.0 g) × 100% / (32.1 g + 16.0 g + 16.0 g) = 49.9%
Explanation:
Step 1: Detemine the mass of O in SO₂
There are 2 atoms of O in 1 molecule of SO₂. Then,
m(O) = 2 × 16.0 g = 16.0 g + 16.0 g = 32.0 g
Step 2: Determine the mass of SO₂
m(SO₂) = 1 × mS + 2 × mO = 1 × 32.1 g + 2 × 16.0 g = 32.1 g + 16.0 g + 16.0 g = 64.1 g
Step 3: Detemine the mass percent of oxygen in SO₂
We will use the following expression.
m(O)/m(SO₂) × 100%
(16.0 g + 16.0 g) × 100% / (32.1 g + 16.0 g + 16.0 g) = 49.9%
Answer:
16.0 g + 16.0 g) × 100% / (32.1 g + 16.0 g + 16.0 g) = 49.9%
Explanation:
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.
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.
Copper is a metal with the ability to conduct electricity, so copper wires are often used in small household appliances. The ability to
conduct electricity is a drag and drop answer here property of copper. Iron, on the other hand, reacts with oxygen to form iron oxide, also
known as rust. The ability of iron to rust is a drag and drop answer here property of the metal As scientists characterize certain metals, they
investigate physical properties like drag and drop answer here and chemical properties like drag and drop answer here.
Answer:
physical property
Chemical property
melting point
Reactivity with a strong acid
Explanation:
The ability to conduct electricity is a physical property of copper. Most electrical cables are made of copper owing to its high electrical conductivity.
The rusting of iron is a chemical reaction. Rust is actually hydrated iron III oxide. Hence it is a chemical property of iron.
The melting points of metals can be used to classify them. The greater the density of metals, the higher their melting point.
The ability of metals to react with acids separates metals into highly reactive, moderately reactive and unreactive metals.
Copper shows physcal property & iron shows chemical property.
What are physical and chemical properties?Physical properties are those properties which are seen by the eye due to change in the outermost appearance, whereas chemical properties are those which are shown due to change in the internal composition.
In the question, it is given that copper metal has a ability to conduct electricity and this property of metal is the physical property, as due to conduction their identity is not changing.
It is also given that iron is showing rusting due to the formation of iron oxide, so it a chemical property as identity of iron changes.
So, scientists characterize certain metals, they investigate physical properties like melting point, conductivity, density, etc. and chemical properties like reactivity with acid, base, oxygen, etc.
Hence, the ability to conduct electricity is a physical property of Cu and the ability of iron to rust is a chemical property.
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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.
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!
Answer:
-189.55°C
Explanation:
Given data:
Initial volume of gas = 3.6 L
Final volume of gas = 15.5 L
Initial temperature = ?
Final temperature = 87°C (87+273 = 360 K)
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₁ = V₁T₂ /V₂
T₁ = 3.6 L × 360 K / 15.5 L
T₁ = 1296 L.K / 15.5 L
T₁ = 83.6 K
Kelvin to °C:
83.6 K - 273.15 = -189.55°C
How many moles of copper are in 6,000,000 atoms of copper?
Answer: There will be 9.9632 × 10⁻¹⁸ moles of Copper in 6,000,000 atoms of Copper.
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
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.
Which electron dot diagram represents H2?
Answer:
H:H
Explanation:
In a double replacement reaction, the ions of two compounds exchange places in an aqueous solution to form two new compounds.
True
False
Answer:
true
Explanation:
Answer:
True
Explanation:
In a displacement reaction, more reactive element displaces less reactive element. Whereas in a double displacement reaction there is exchange of ions of two compounds.
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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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: