A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.
A mixture is made by combining 1.61 lb of salt and 5.37 lb of water. What is the percentage of salt (by mass) in this mixture?
Answer:
Hey okau
Explanation:
X/100% = part / whole
X/100% = 1.62 / (1.62 + 4.81) = 0.252
X = 25.2%
Sn + 2HCI --> SnCl2 + Hz
a. synthesis
b. single replacement
C. combustion
d. double replacement
e. decomposition
Answer:
Option B. Single replacement reaction
Explanation:
To know which option is correct, it is important that we know the definition of each option. The definition of each option is given below:
1. Synthesis reaction is a reaction in which two different elements or compound combine together to produce a new compound different from the two starting elements or compound. An example is illustrated below:
C + D —> E
2. Single replacement reaction is a reaction in which an element replaces or displaces another element in a compound. An example is illustrated below:
D + BC —> B + CD
3. Combustion reaction is a reaction in a substance react with oxygen to generate carbon dioxide (CO₂) and water (H₂O). An example can be seen when organic compound react with oxygen to produce carbon dioxide (CO₂) and water (H₂O). This is illustrated below:
CₓHᵧ + (x + y/4) O₂ —> xCO₂ + (y/2) H₂O
4. Double replacement reaction is a reaction in which the ions of the two reacting compound replaces one another to form new products. This is illustrated below:
X⁺Y¯ + U⁺V¯ —> X⁺V¯ + U⁺Y¯
5. Decomposition reaction is a reaction in which a large compound breaks down into two or more elements or compound. An example is illustrated below:
GH —> G + H
Now, observing the equation given in the question above:
Sn + 2HCl —> SnCl₂ + H₂
We can see that Sn replaces H in HCl to produce SnCl₂.
Therefore, the reaction is a single replacement reaction.
fluorine is more reactive than chlorine.
Answer:
yes because of fluorine has higher electronegativity
What ways is carbon added to the atmosphere
Answer:
One way is through fossil fuels. When people burn fossil fuels it enters the atmosphere as carbon dioxide gas. Another way is through animals. Most animals exhale carbon dioxide as a waste product which gets into the atmosphere.
True or false: potential energy increases as like charges get closer to one another
Crude oil has many applications once it has been distilled at a refinery. According to the diagram, what process is used to distill crude oil into its various components to use energy distribution?
A) separation by density
B) separation by boiling points
C) separation by the porosity of the components
D) separation by the organic content or each component
Answer:
B) separation by boiling points
Explanation:
According to the diagram depicted, crude oil is separated into its different units using boiling points.
The boiling points of a compound is the temperature at which it begins to boil. The process of fractional distillation is used in the oil industry to separate crude oil into its components. When the boiling point of a oil fraction is reached, it becomes vaporized and rises within the columnPressure is often defined as
Answer:
Pressure is often defined as a measure of force applied on an area, or over a unit area.
Explanation:
Based on the number of valence electrons indicated by its location in the periodic table ,which elements behavior would you predict to be closest to that of potassium (k)
Answer:
Na sodium or Rb rubidium
Explanation:
Because Na is present in first group all members of group 1 have 1 electron in valence shell and show similar properties.
how many electrons does a covelent bond consist of?
Answer: 2 electrons
Explanation: Good luck! :D
I need help on these questions!
Answer:
See explanation
Explanation:
Given that;
E = hc/λ
h = 6.63 * 10^-34 Js
c = 3 * 10^8 ms-1
λ = ?
E = 3.978 * 10^-19 J
λ = hc/E
λ = 6.63 * 10^-34 * 3 * 10^8 /3.978 * 10^-19
λ = 19.89 * 10^-26/3.978 * 10^-19
λ = 5 * 10^-7 m The colour is green
2. E = hc/λ
E= 6.63 * 10^-34 * 3 * 10^8 /1000 * 10^-9
E = 1.989 * 10^-19 J
But
E = hf
f = E/h
f = 1.989 * 10^-19/6.63 * 10^-34
f = 3 * 10^14 Hz The radiation is infrared
3. E = hc/λ
λ= hc/E
λ= 6.63 * 10^-34 * 3 * 10^8 /2.0 * 10^-14
λ= 995 * 10^-14 m This is gamma radiation
4. E = hc/λ
E=6.63 * 10^-34 * 3 * 10^8 /620 * 10^-9
E = 3.2 * 10^-19 J
5. E = hf
E= 6.63 * 10^-34 * 2 * 10^17
E = 1326 * 10^-19 J
E = hc/λ
λ= hc/E
λ= 6.63 * 10^-34 * 3 * 10^8 /1326 * 10^-19 = 15 * 10^-9
This is ultraviolet radiation
How do I round 74,000 to have only one significant figure?
Answer:
7x10⁴.
Explanation:
Hello!
In this case, when rounding big number to a representation with less significant figures than it, we need to make sure we remove the spare figures and round up whether the next digit is five or more.
In such a way, for 74,000, we notice that 4 is not enough to round up the 7, that is why the number would contain a 7 only; moreover, to get rid of the thousand places, we need to introduce an exponent in 4 places, which means that the result would be:
7x10⁴.
Best regards!
differentiate between normal publication window and the story editor window in desktop publishing
The main differentiation between given windows is that in normal publication window we can edit the document after generation also and the story editor window in desktop publishing we can not able to edit after generation.
What is windows?Windows in the computer world is a part of the graphical user interface (GUI), which is a separate viewing area on the display of monitor where they allow multiple viewing area.
In the normal publication window, word processing software like Microsoft Word, Pages, Writer and WordPerfect comes which is used to create any text document like resume, report, thesis, etc. which can be manipulate after the generation also.The story editor window in desktop publishing is used to create page layouts of any documents for publication in print or online.Hence, in the above paragraph differentiation is given.
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Determine the oxidation number of
Sulphur in Sodium thiosulphate
The oxidation number of Sulphur = +2
Further explanationGeneral formula for determining Oxidation Numbers :
1. The number of oxidation of single element atoms = 0. Examples of Ar, Mg, Cu, Fe, N₂, O₂, etc. = 0
Group I : +1
Group II : +2
H in compound = +1, except metal hydride compounds (Hydrogen which binds I or II groups) oxidation number H = -1, for example, LiH, MgH₂, etc.
2. Oxidation number O in compound = -2, except OF2 = + 2 and in peroxide (Na₂O₂, BaO₂) = -1 and superoxide, for example KO₂ = -1/2.
3 The oxidation number in a non-filled compound = 0,
The total amount of oxidation in ion = ion charge, Example NO₃⁻ = -1
Sodium thiosulphate - Na₂S₂O₃
Oxidation number Na = +1 ⇒x2 = +2
Oxidation number O = -2 ⇒x3 = -6
Oxidation number Na₂S₂O₃ = 0
2.Na+2.S+3.O=0
2.+1+2.S+3.(-2)=0
2+2S-6=0
-4+2S=0
2S=4
S=+2
which soil would be the best for growing plants?
Honestly, its based on your preference but the best recommended one would be loam. I use loam too, and it is really good for growing the plants.
:)
Construct an explanation using Newton's Laws of Motion to describe the effects of balanced and unbalanced forces on the motion of an object.
Answer:
The manner in which objects will move is determined by the answer to this question. Unbalanced forces will cause objects to change their state of motion
Explanation:
Since these two forces are of equal magnitude and in opposite directions, they balance each other.
Answer:
balance force are those force whose resultant force is zero and unbalanced force are those whose resultant are non zero
the man is being warmed by?
radiation
convention
conduction
Answer:
Comvection
Explanation:
The movement causes the density to rise and therefore transfer more heat
The number of calories listed on a food label always refers to the number in the entire package
What was the unknown metal?
Answer:
is there a picture or something?
Explanation:
Explanation:
Your question is incomplete please update it.
how many 500 mg tablets of acetaminophen would be a lethal dose for a 132 lb adult
Answer:
About 2000 mg so 4 pills
could kill
Explanation:
Need help asap
1. All nonmetals (except hydrogen) have 8 valence electrons?
True or False
2. The N^-3 ion is classified as a(n) ____ and has ____.
A. anion, 8 valence electrons
B. cation, 8 valence electrons
C. anion, 15 valence electrons
D. anion, 3 valence electrons
3. If two nonmetals react to form a compound and have very different _____ they form ____ bonds. If there is a small difference, then they form ____ bonds.
A. ionization energy; covalent; nonpolar ionic
B. electronegativity; nonpolar covalent; polar covalent.
C. ionization energy, ionic, nonpolar covalent
D. electronegativity, polar covalent, nonpolar covalent.
Answer:
1: false
2: B
Explanation:
I do not know the 3rd one
You want to determine the concentration of a phosphoric acid (H3PO4) solution using a standardized 0.0995 M NaOH solution. 10.00 mL of the H3PO4 solution needed to be titrated with 22.85 mL of the standardized 0.0995M NaOH solution to reach the equivalence point. What is the concentration of the H3PO4 solution
Answer:
Explanation:
H₃PO₄ + 3NaOH = Na₃PO₄ + 3 H₂O.
1 mole 3 mole
22.85 mL of the standardized 0.0995M NaOH solution will contain
.0995 x .02285 moles of NaOH
= 22.7357 x 10⁻⁴ moles of NaOH
3 moles of NaOH reacts with 1 mole of H₃PO₄
22.7357 x 10⁻⁴ moles of NaOH reacts with 1 x 22.7357 x 10⁻⁴ / 3 mole of H₃PO₄
= 7.5785 x 10⁻⁴ moles of H₃PO₄
7.5785 x 10⁻⁴ moles of H₃PO₄ is contained in 10 mL or 10⁻² L
molarity of H₃PO₄ solution = 7.5785 x 10⁻⁴ / 10⁻²
= 7.58 x 10⁻² M
= .0758 M .
All moving objects have kinetic energy. True False
Answer:
true
.......................
Answer: You're Welcome!
Oh, It's False - Kinetic energy depends upon the speed of the object; potential energy depends upon the position of the object.

Someone unscramble the first mystery element because I don’t know how to.
-unnecessary comments will be reported
Answer:
Calcium
Explanation:
The symbol for the element with a mass number of 27 is actually Al for Aluminum instead of Co for Cobalt. Mass number refers to atomic mass, not atomic number.
Aluminum has an atomic mass of 26.982 or 27.
The letters to unscramble are I, M, C, Al, U, and C.
The mystery element is Calcium.
Hope that helps.
Copper metal reacts with silver nitrate to produce silver metal and copper (II) nitrate.
the correct equation for this reaction is:
A: Cu + SiN—> Si + Cu2N
B: 2Cu + AgNO3–> Ag +
Cu(NO3)2
C: Cu + 2 AgNO3–> Ag + Cu(NO3)2
D:Cu + AgNO3–> Ag + CuNO3
Answer:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
Explanation:
The reactants are:
Copper metal = Cu
Silver nitrate = AgNO₃
The products are:
Silver metal = Ag
Copper (II) nitrate = Cu(NO₃)₂
So, the reaction equation is given as;
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
This is a single displacement reaction
Shivani measures out 6.0 moles of epsom salt (MgSO) to put her bath. How many grams MgSO4 went in the bath?
Answer: 720 g
Explanation:
To solve this we must be knowing each and every concept related to mole. Therefore, shivani measures out 6.0 moles of epsom salt (MgSO[tex]_4[/tex]) to put her bath. 1,566g MgSO[tex]_4[/tex] went in the bath.
What is mole?A mole is merely a measuring unit. In reality, it is one of its International System of Units' seven foundation units. When current units are insufficient, new units are created.
Chemical reactions frequently occur at levels where employing grams would be inappropriate, but using absolute quantities of atoms/molecules/ions would also be misleading.
For all practical reasons, one mole of a substance in grams is nearly equal to 1 molecule for the compound per daltons.
Mathematically,
number of mole =given mass ÷ molar mass
number of mole=6.0 moles
molar mass of epsom= 261.47g/mol
substituting all the given values in the above equation, we get
6.0 moles =mass of epsom ÷ 261.47g/mol
mass of epsom =1,566g
Therefore, 1,566g MgSO[tex]_4[/tex] went in the bath.
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Use your periodic table to determine which of the following is a non metal
A.Nitrogen
B. Lithium
C. Sodium
D. Gold
Why is it easier to switch to solar and wind energy as compared to other alternative energy sources? Select all that apply.
A. They are more cost-effective.
B. They require large, easily obtainable parcels of land.
C. They can be produced easily in areas with geothermal activity.
D. The land can be used for other purposes while supplying energy.
Answer:C. They can be produced easily in areas with geothermal activity.
D. The land can be used for other purposes while supplying energy.
Explanation:
Both c and d are correct
It is easier to switch to solar and wind energy as compared to other alternative energy sources because they can be produced easily in areas with geothermal activity and can be used for other purposes while supplying energy.
What is solar energy?Solar energy is any type of energy generated by the sun. Solar energy can be harnessed directly or indirectly for human use.
Generating energy that produces no greenhouse gas emissions from fossil fuels and reduces some types of air pollution.
Diversifying energy supply and reducing dependence on imported fuels. Creating economic development and jobs in manufacturing, installation, and more.
Hence, options C and D are correct.
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Is Gold (Au) soluble?
Answer:
yes
Explanation:
In table below, there are descriptions of an experiment on samples of three different chemical compounds. Decide whether the compound is ionic or molecular, if you can. If there is not enough information to decide, choose can't decide in the third column.
Compound Description Ionic or molecular?
can't decide
1 Compound 1 is a hard grayish-white solid. A small 250. mg
sample of it is put into a quartz tube and heated strongly.
It starts to melt at 1055. °C.
2 Compound 2 is a hard grayish-white solid. When tapped
gently with a small hammer, a sample fractures into
fragments and a whitish powder. The powder is soluble in
water, and when 15 g are dissolved in 100 mL of water,
the solution conducts electricity well.
3 Compound 3 is a soft waxy white solid that can be easily
shaped and molded by hand. When the flame of an ordinary
laboratory burner is held about 10 cm away from the solid,
it rapidly and extensively melts into a clear liquid.
Answer:
Compound 1- ionic solid
Compound 2- can't really decide
Compound 3- molecular solid
Explanation:
An ionic solid has a very high melting point. It is hard but not brittle. It's solution or melt but not it's solid conducts electricity. Compound 1 is an ionic solid.
We can't really decide on compound 2 since it is brittle yet it's solution conducts electricity.
Lastly, compound 3 is a molecular solid since it has a low melting point.
Answer:
Compound 1- ionic solid
Compound 2- can't really decide
Compound 3- molecular solid
Explanation:
26. A Grignard's reagent may be made by
reacting magnesium with which of the
following compound ?
(A)
Methyl amine
(B) Diethyl ether
(C
)
Ethyl iodide
(D)
Ethyl alcohol