Answer:
See explanation
Explanation:
Usually, when we write a chemical formula for any compound or other chemical specie, we use subscripts to;
Indicate the ratio of atoms of each element present in the compound or chemical specieShow the number of atoms of each element present in the compound or chemical specie.Hence, the subscripts written after chemical formulas have more than one function as described above.
In H2SO4 for instance, there are two hydrogen atoms, one sulphur atom and four oxygen atoms as shown in the chemical formula.
cells in animals and plants use the ___ that plants put in the air
Answer:
oxygen
Explanation:
plants and animals use oxygen
A student has two solid blocks that have different masses. The student knows that each block is composed of a pure substance, but she wants to know if the blocks are composed of the same pure substance. Which of these would best show that the blocks are composed of different substances?
A.
Both blocks can be scratched by a piece of glass.
B.
One block has a greater volume than the other block.
C.
Both blocks sink when placed in water.
D.
One block conducts electricity and the other does not.
Answer:
The answer is maybe B hope it helps
The substances which are made up of only one kind of particle and have a fixed or constant structure is defined as the pure substance. Here One block has a greater volume than the other block so that the blocks are composed of different substances. The correct option is B.
What is volume?The amount of space occupied by any three dimensional solid is known as the volume. These solids can be a cube, a cuboid, a cone, a cylinder or a sphere. It is simply how much space an object or substance takes up.
It is possible to have the volume without mass, such as an enclosed vacuum. The capacity of a container is not necessarily the same as its volume. It is the interior volume of a vessel. If you measure the exterior dimensions of the container, its volume is greater than its capacity.
Here the blocks are composed of different substances is indicated by the difference in the volume of the blocks.
Thus the correct option is B.
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Which choice identifies the compound's structural formula, and what information does the structural formula provide
that the molecular formula does not?
Image B represents the structural formula, and only the structural formula allows the molecular
shape to be determined because it shows the position and alignment of the atoms and bonds.
Image B represents the structural formula, and only the structural formula allows the number of
atoms of each element in the compound to be determined because it provides subscripts.
Image A represents the structural formula, and only the structural formula allows the type of
bond formed by the compound to be determined because it shows the element symbols written
in order (metals and then nonmetals).
Image A represents the structural formula, and only the structural formula allows the bond
length of each bond between the atoms of the compound to be determined because it shows the
bonds represented by a line.
Answer:
second opinion is correct
How can your body be at risk for diseases?
Answer:
I'm not sure if this is true but in science class I learned that stress can cause a risk of diseases
Explanation:
the more months of stress you have, the higher the risk
answer 1-5 of lesson outline for brainiest
Answer:
see explanation
Explanation:
1. mid-ocean ridge
2.gravity
3.normal,reverse
4.cools
5.stripes
6.spreading
7.continents
Calculate the number of moles in 7.04 g of lead (II) nitrate, Pb(NO3)2
Can Someone help me covert this?!
Answer:
moles Pb(NO₃)₂ ≅ 0.0213 mole (three sig. figs.)
Explanation:
converting...
grams to moles => divide by formula weight
moles to grams => multiply by formula weight
for this problem ...
moles Pb(NO₃)₂ = 7.04g / 331.2g/mol = 0.021256 (calculator answer)
≅ 0.0213 mole (three sig. figs.)
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, the number of moles in 7.04 g of lead (II) nitrate, Pb(NO₃)₂ is 0.0212moles.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
mole =given mass ÷ molar mass
Molar mass of 1 mole of Pb(NO₃)₂ = 331.2g/mol
given mass of Pb(NO₃)₂=7.04g
Substituting the values in above formula we get
moles of Pb(NO₃)₂ = 7.04g / 331.2g/mol
moles of Pb(NO₃)₂ = 0.0212moles
Therefore, the number of moles in 7.04 g of lead (II) nitrate, Pb(NO₃)₂ is 0.0212moles.
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9 moles of Ammonia (NH3) are added to 50 L of H2O at a temperature of 29°C. The vapor pressure of water alone is 29.96 mmHg at 29°C. What is the vapor pressure of the Ammonia solution?
Answer: The vapor pressure of the solution at [tex]29^0C[/tex] is 29.86 mm Hg
Explanation:
As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.
The formula for relative lowering of vapor pressure will be,
[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]
where,
[tex]\frac{p^o-p_s}{p^o}[/tex]= relative lowering in vapor pressure
i = Van'T Hoff factor = 1 (for non electrolytes)
[tex]x_2[/tex] = mole fraction of solute
=[tex]\frac{\text {moles of solute}}{\text {total moles}}[/tex]
Given : 9 moles of [tex]NH_3[/tex] are dissolved in 50 L or 50000 ml of water
mass of water = [tex]density\times volume = 1g/ml\times 50000ml=50000g[/tex]
moles of solvent (water) = [tex]\frac{\text{Given mass}}{\text {Molar mass}}=\frac{50000g}{18g/mol}=2778moles[/tex]
Total moles = moles of solute + moles of solvent = 9 mol + 2778 mol = 2787
[tex]x_2[/tex] = mole fraction of solute
=[tex]\frac{9}{2787}=3.2\times 10^{-3}[/tex]
[tex]\frac{29.96-p_s}{29.96}=1\times 3.2\times 10^{-3}[/tex]
[tex]p_s=29.86mmHg[/tex]
Thus the vapor pressure of the solution at [tex]29^0C[/tex] is 29.86 mm Hg
Mass = 22g Volume = 2cm3 What is the Density?
Answer:
11g/cm^3
Explanation:
The density of a substance can be found By
density= Mass/volume
From the question
mass = 22 g
volume = 2 cm³
22/2=11
We have the final answer as
11 g/cm³
Answer:
11g/cm^3
Explanation:
It is because the constant formula density is
Density=Mass/ Volume.
Therefore we have
Density=22g/2cm^3
Which is = 11g/cm^3
You weigh out 0.1183 g of a complex salt to analyze for the percentage of cyanide ion in your complex salt. After dissolving the complex salt in solution, you determine that it takes 10.02 mL of a 0.08035 M potassium permanganate solution to react with all of the cyanide ion in your complex salt. Using the balanced chemical equation provided, determine the mass percentage of the cyanide ion in your complex salt. (Remember: the mole ratio of MnO4 - to KMnO4 is 1:1)
Answer:
25.35%
Explanation:
Again let me restate the the equation of the reaction;
H2O (ℓ) + 2 MnO4 - (aq) + 3 CN- (aq) → 2 MnO2 (s) + 3 CNO- (aq) + 2 OH- (aq)
Amount of potassium permanganate reacted = 10.2/1000 * 0.08035 = 8.1957 * 10^-4 moles
If 2 moles of MnO4 - reacts with 3 moles of CN-
8.1957 * 10^-4 moles of MnO4 - reacts with 8.1957 * 10^-4 * 3/2
= 1.229 * 10^-3 moles of CN-
Mass of CN- reacted = 1.229 * 10^-3 moles of CN- * 26.02 g/mol
= 0.03 g
Hence, percentage of the cyanide = 0.03 g/0.1183 g * 100
= 25.35%
the formulas of three important acids and three important bases and describe their uses.
Answer:
18929eu9sisjwiejwjxjjejxme
2 questions. will give brainliest if i can figure out how
What happens to the electrons of a reducing agent during a reaction?
a.Electrons are gained
b.Electrons are lost
c.Electrons are held
d.Electrons are doubled
When is a substance reduced during an oxidation reduction reaction?
a.After one substance is oxidized
b.Before one substance is oxidized
c.Same time as one substance is being oxidized
d.Only oxidation occurs
1= b. electrons are lost
2= a. after one substance is oxidized
seaborgium mass number =
Explanation:
seaborgium Is a type of corn that is grown in warm countries.
answer is SG
Answer:
269 u
Explanation:
Did Dalton believe that atoms could be created or destroyed? Explain
☁️ Answer ☁️
Yes.
"In so doing, he became the first scientist to explain the behavior of atoms in terms of the measurement of weight. He also uncovered the fact that atoms couldn't be created or destroyed. Dalton's theory additionally examined the compositions of compounds, explaining that the tiny particles (atoms) in a compound were compound atoms"
Hope it helps.
Have a nice day noona/hyung.
sub-atomic particles like negatively charged electrons, positively charged
protons and electrically ________ neutrons
Answer:
neutral
Explanation:
There are three basic subatomic particles. These are;
Protons (positively charged)Electrons (negatively charged)Neutrons (neutral)A neutron has no charge unlike the proton and the electron. It is present in the nucleus and contributes to the mass of the atom.
A compound or material formed by a chemical reaction is known as the ____ of that reaction.
Answer:
Its is the product.
Explanation:
A buffer is made with 0.493 M of the weak base methylamine ([tex]CH3NH2[/tex]) with 0.493 M [tex]CH3NH3Cl[/tex] (KA = 5.6 x 10^-4)
What is the pH of this buffer system?
If 0.100 M HBr is added to the buffer, what is the pH?
h^ ar hidrojen oksijen azot helyum
Pls help!
the chemical that is responsible for stopping reaction is called the ____
Answer:
reactant
Explanation:
I watched a chem video and this is what they called it.
Gerald's science teacher mixed liquid X and liquid Y, both at room-temperature, in a large beaker. two beakers of clear solutions to the left of a right-pointed arrow, and a large beaker with a clear solution to the right of the arrow The mixture in the large beaker still looked clear like water, but when the students, one at a time, carefully touched the outside of the large beaker, it felt warm to the touch. Why did the large beaker most likely feel warm? A. The two liquids were not soluble in water. B. The release of a gas heated the solution. C. A chemical reaction produced a new substance. D. The energy of mixing warmed the liquids.
Answer:
c
Explanation:
A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
What is chemical reaction?chemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances.
A chemical reaction is one in which two or more reactants will react to form a new substance. When new substance will form it will produce heat. Therefore, when science teacher was mixing two liquids it was generating heat.
Heating a substance allow molecules to move faster. When heat is given to the object it will move fast. When heat will apply to a solid it will turn into liquid. When heat is supplied to the liquid it will turn into gas.
Therefore, A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
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There are 4 mg of lead present in 2000 g of a water sample. What is the
concentration of lead in m?
Answer: 130 ppm Pb
Explanation:
We use parts per million to express the concentrations of solutions that contain very, very small amounts, often called trace amounts, of a given solute.
More specifically, a solution's concentration in parts per millions tells you the number of parts of solute present for every
10
6
=
1
,
000
,
000
parts of solution. You can thus say that a
1 ppm
solution will contain exactly
1 g
of solute for every
10
6
g
of solution.
In your case, you know that you have
38
mg Pb
⋅
1 g
10
3
mg
=
3.8
⋅
10
−
2
.
g Pb
in exactly
300.0 g
=
3.000
⋅
10
2
.
g solution
This means that you can use this known composition as a conversion factor to scale up the mass of the solution to
10
6
g
10
6
g solution
⋅
3.8
⋅
10
−
2
.
g Pb
3.000
⋅
10
2
g solution
=
130 g Pb
Since this represents the mass of lead present in exactly
10
6
g
of solution, you can say that the solution has a concentration of
concentration
ppm
=
130 ppm Pb
−−−−−−−−−−−−−−−−−−−−−−−−−−−−
The answer is rounded to two sig figs, the number of sig figs you have for the mass of lead present in the sample.
how did the report on the topic of climate change help the general public relate to the topic?
Answer:
Report of the climate change can help the people. As when people wants to go for picnics or somewhere else. They did not have any idea that what will be the climate when they go. Report of climate change help him to choose the right time for going on picnics or somewhere else.
Answer:
The report mentioned ways that people’s lives may change because of climate change, such as rising sea levels, reduced crop efficiency, and heat waves. This information may encourage the public to change the way they use energy, for example how they heat their homes or power their cars.
Explanation:
A copper coin with a mass of 6.30 grams changes temperature in the sunshine from 20.0°C to 32.0°C. How much energy is transferred? The specific heat capacity of copper is 0.377 joules/gram degree Celsius. Express your answer to three significant figures.
The amount of energy transferred to the coin is
joules.
Answer:
q = mC∆T
q = heat = ?
m = mass = 6.30 g
C = specific heat = 0.385 J/g/deg
∆T = change in temperature = 32-20 = 12º
q = ((6.30 g)(0.385 J/g/deg)(12 deg) = 29.1 J (to 3 significant figures)
Explanation:
4 NH3 + 302
2N2 + 6H₂O
2.) a) A chemist burned 0.25 moles of ammonia gas (NH,) in the presence of excess oxygen
pps to produce 2.95 grams of nitrogen gas (N2). Calculate the theoretical yield of
nitrogen gas.
Answer:
this is hard
Explanation:
Answer:
I'm not sure but maybe 1 g ?!
Write the formula for Zn+2 (SO4)-2
Answer:
Zn2 + SO4 = Zn2(SO4)2
Explanation:
Nitrogen is used to keep food frozen during transportation.
Which properties make it suitable for this?
Answer:
Gaseous nitrogen has unique chemical and physical properties that make it suitable for use in food processing. Nitrogen is inert which means it will not react with prepared food materials, which can alter their aromas or flavors. Also, gaseous nitrogen will effectively displace oxygen minimizing oxidation and the growth of microorganisms that cause foods to lose their freshness and deteriorate faster.
Explanation:
Source: https://www.generon.com/using-nitrogen-gas-in-food-packaging/
"Because it deflects oxygen, nitrogen is just a common gas for food packing." Because oxygen will carry moisture, this is critical. Bacteria use oxygen to grow and survive on organic matter. Bacteria find it much harder to develop while as much oxygen as possible is removed.
What is food packing?Food packaging is the process of packaging food. A package provides security, resistance to manipulation, and particular physical, chemical, and even biological requirements. Food packaging may include a nutrition label and other information about the product being sold.
What is bacteria?Bacteria are commonly found, mostly free-living organisms with one biological cell. They belong to the prokaryotic organisms category. Bacteria, which have been typically a few micrometers long, were one of the first living species to originate on Earth and may be found in practically every ecosystem.
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Which type of fuel do you predict might have the
greatest impact on carbon dioxi de levels in the
atmosphere?
Please answer this. If your just gonna give me a fake answer please just don’t
Answer:
If the choices were coal, petroleum, and natural gas, I would say that petroleum has the greatest impact on the CO₂ levels in the atmosphere. I chose petroleum because of transportation, such as cars, trucks, planes, and more.
How is activation energy represented on an energy diagram?
Energy
Reactants
Products
Reaction Progress
O A. Activation energy is the distance from the reactants to the top of
the "hill."
B. Activation energy is the distance from the top of the "hill to the
products.
O C. Activation energy is the final energy level of the product
molecules.
o
D. Activation energy is the starting energy level of the reactant
molecules.
In accordance with the diagram, activation energy is the distance from the reactants to the top of the "hill"
The activation energy represented on the energy diagram is as given as
"Activation energy is the distance from the reactant to the top of the hill"
So, the correct option is A.
What is activation energy?The minimum amount of energy required by the reactant to do the reaction is called activation energy.
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the form of energy that your lunch represents is?
A) electrical
B) chemical
C) thermal
D) nuclear
chemistry-mole calculations
Answer:
somebody answer this please>>>!!!
Explanation:
!!!
If 0=30° then verify that sin20=2sin0.cos0
Answer:
It is proved that sin20=2sin0.cos0
Explanation:
Given
[tex]0=30[/tex] °
[tex]sin20=2sin0.cos0[/tex]
Substituting the value of "0" on both the sides, we get -
[tex]sin2 (30) =2sin 30 * cos 30\\sin 60 = 2 * sin 30 * cos 30 \\0.866 = 2 * 0.5 * 0.866\\0.866 = 0.866[/tex]
Since LHS = RHS
we can say that [tex]sin20=2sin0.cos0[/tex]
Is Chlorine and Sodium an Ionic or Covalent bond?
Answer:
It is an Ionic bond