B. Developing theories using many lines of evidence
Answer:
B.
Explanation:
Suggest why the colour of the copper sulfate solution fades during electrolysis.
Please help! Thank you:)
Answer:
The traces of hydrogen ions are not discharged, so you not see any gas bubbles collecting on the negative cathode electrode. The blue colour fades as more and more copper is deposited, depleting the concentration of the blue copper ion Cu2+ ions in solution.
Explanation:
In the past mining companies were not made responsible for the clean-up of any of
the mine sites. As a result, abandoned mines had a severe impact on the
environment in Ontario. Which of these is not a result of these mining practices?
a)
Chemical reactions producing sulphuric acid decrease soil and water ph in the
area.
b)
Acid leaching dissolves metals found in the soil thus allowing them to enter
the water system.
c)
Heavy metals which are left tailing ponds can dissolve and enter the water
system.
d)
Old and inefficient mining smokestacks contaminate the soils around
abandoned mine sites.
Explain the difference between the way a molecule (which does not ionize) dissolves and an ionic compound dissolves, using sugar water and salt water as an example
Answer:
The molecules (which do not ionize) dissolves in water depends on the polarity of molecules while the ionic compounds that dissolve in water depend on the electric charge of the compound.
For example sugar dissolves in water because of the polar nature of sugar which releases energy and form intermolecular bonds with the polar water molecules.
While salt dissolves in water as salt has a net electric charge that attracted by the oppositely charged ions present in the water. The attractive force between salt and water is stronger than sodium and chloride and allow salt to dissolve in the water.
Which statement describes what is gained or lost during radioactive decay?
Atoms gain other atoms.
Elements take in energy.
Atoms lose smaller particles.
Elements gain smaller particles.
only one answer
Answer:
The answer is
Atoms gain other atoms
Hope this helps you
Answer:
AAAAAAAAAAAA!!!!!!!
Explanation:
Which statement correctly describes Earth’s magnetic field?
A) A compass can lead a hiker to the geographic North Pole.
B) The magnetic pole near the South Pole is a north pole.
C) Compasses point toward a magnetic pole that is a north pole.
D) Field lines circle Earth from east to west.
Answer:
B) The magnetic pole near the South Pole is a north pole.
Explanation:
The north pole on the compass is the geographical South Pole.
Hope it helps.
Answer:
The answer is B.
Explanation:
Given the following equation: 4 Fe + 3022 Fe2O3 What mass of iron is needed
to react with 12 grams of oxygen gas? *
Answer : The mass of iron needed is 29.5 grams.
Explanation : Given,
Mass of [tex]O_2[/tex] = 12 g
Molar mass of [tex]O_2[/tex] = 32 g/mol
First we have to calculate the moles of [tex]O_2[/tex].
[tex]\text{Moles of }O_2=\frac{\text{Given mass }O_2}{\text{Molar mass }O_2}[/tex]
[tex]\text{Moles of }O_2=\frac{12g}{32g/mol}=0.375mol[/tex]
Now we have to calculate the moles of [tex]Fe[/tex]
The balanced chemical equation is:
[tex]4Fe+3O_2\rightarrow 2Fe_2O_3[/tex]
From the reaction, we conclude that
As, 3 moles of [tex]O_2[/tex] react with 4 moles of [tex]Fe[/tex]
So, 0.375 mole of [tex]O_2[/tex] react with [tex]\frac{4}{3}\times 0.375=0.5[/tex] mole of [tex]Fe[/tex]
Now we have to calculate the mass of [tex]Fe[/tex]
[tex]\text{ Mass of }Fe=\text{ Moles of }Fe\times \text{ Molar mass of }Fe[/tex]
Molar mass of [tex]Fe[/tex] = 59 g/mole
[tex]\text{ Mass of }Fe=(0.5moles)\times (59g/mole)=29.5g[/tex]
Therefore, the mass of iron needed is 29.5 grams.
Two atoms have the same relative atomic mass but different chemical properties.
Which row about the proton and neutron numbers of these atoms is correct?
Answer:
A
Explanation:
Protons are the ones which give rise to different elements, hence different elements have different chemical properties. Therefore, the two atoms must have different proton numbers.
The relative atomic mass of an atom is determined by the mass of the neutrons and the protons. The mass of the electrons are not included due to their negligible mass (1/1840).
Hence, due to the different proton masses, the masses of the neutrons will also differ to ensure that both atoms have the same relative atomic mass.
The overall process of photosynthesis has the balanced chemical equation 6CO, +6H,0 CH.0, 60, What does this tell you about the relative amounts of carbon
dioxide and water consumed in this process?
A. For every six moles of carbon dioxide consumed, one mole of water is consumed
B. For every mole of carbon dioxide consumed, one mole of water is consumed
C. For every gram of carbon dioxide consumed, one gram of water is consumed
D. For every six grams of carbon dioxide consumed, one gram of water is consumed.
Answer:
(C)
Explanation:
Because of the physics of it.
According to the overall equation of photosynthesis as follows: 6CO2 + 6H2O = C6H12O6 + 6O2, for every mole of carbon dioxide consumed, one mole of water is consumed.
What is photosynthesis?Photosynthesis is the process by which plants and other photoautotrophs convert light energy into chemical energy.
Photosynthesis makes use of carbon dioxide and water to produce glucose and oxygen as follows:
6CO2 + 6H2O = C6H12O6 + 6O2
This chemical equation suggests that for every mole of carbon dioxide consumed, one mole of water is consumed.
Learn more about photosynthesis at: https://brainly.com/question/1388366
#SPJ6
molar mass of c16h19n305s
Answer:
365.212
Explanation:
According to the given situation, the calculation of molar mass is shown below:-
Data provided
[tex]c_{16}\ h_{19}\ n_3\ o_5\ S[/tex]
Molar mass = 16 × 12 + 19 × 1.008 + 3 × 14 + 5 × 16 + 32.06
= 192 + 19.152 + 42 + 80 + 32.06
Molar mass = 365.212
Therefore for determining the molar mass we simply solve the above equation.
So, the correct answer is 365.212
What is an example of an internal stimulus to which plants can respond? 1. temperature 2. hormones 3. soil conditions 4. light
Answer:
Hormones
Explanation:
Temperature, soil conditions, and light are all external stimuli that the plants can respond to; therefore, hormones would be the only internal stimulus.
Consider preparing ammonia gas by the following reaction:
N2(g) + 3H2(g) ===> 2NH3(g)
If you have 28.02 g of N2 and excess H2, how many grams of NH3(g) can be produced.
6.06g
14.01g
34.08 g
68.16 g
28.02g
Answer:
34.08g
Explanation:
(Take the atomic mass of N=14.0, H=1.0)
no. of moles = mass / molar mass
no. of moles of N2 used = 28.02 / (14x2)
= 1 mol
Since H2 is in excess and N2 is the limiting reagent, the no. of moles of NH3 produced depends on the no. of moles of N2 used.
From the equation, the mole ratio of N2:NH3 = 1: 2,
which means one mole of N2 produces 2 moles of NH3.
From the ratio, we can deduce the no. of moles of NH3 produced = 1 x 2 =2moles.
Mass = no. of moles x molar mass
Mass of NH3 produced = 2 x (14.0+1.0x3)
= 34g
≈34.08g (this happens because the atomic mass I took is only corrected to 1 decimal place, but in the end, this is only a very small error in the decimals. Make sure you take a look if the question provides the atomic mass:) )
In the equation 2KCIO3 → 2KCI + 302, how many moles of oxygen are produced when 12.61 mol of
KCIO3 decompose completely?
Select one:
O a. 19
Ob. 8.4
O c. 6.3
O d. 13
PLEASE I AM BEGGING PLEASE HELP ME
Answer:
A 19
Explanation:
2 mole of KClO3 produces 3 mole of O3
2 : 3
1 : 3/2
12.61 : 3/2 × 12.61
12.61 : 18.9
12.61 mole of KClO3 produces 18.9mole of O2.
In what way does the shape of a molecule affect how the molecule is involved with living systems?
A. It determines the weight of a molecule
B. it determines what elements are in a molecule
C. it determines oxidation states present in a molecule
D. it determines how the molecule functions
There are two characteristics of molecules, one is geometry and other is shape. Shape is excluding lone pair surrounding the central element and geometry is including the lone pair. Therefore, the correct option is option D.
What is VSEPR theory?VSEPR stands for valence shell electron pair repulsions. VSEPR theory is used to predict the shape and geometry of molecules on the basis of valence electrons pairs that are present around the central element of the molecule.
According to VSEPR theory, Lone pair lone pair repulsion is greater than bond pair bond pair repulsion. There are so many limitations of VSEPR theory. There is a repulsion between bond pair electrons and lone pairs present on the central element. The shape of a molecule affect how the molecule is involved with living systems as it determines how the molecule functions.
Therefore, the correct option is option D.
To know more about VSEPR theory, here:
https://brainly.com/question/19582124
#SPJ2
One mole of any gas at room
temperature and pressure will
occupy liter(s).
A. 10
B. 1
C. 22.4
D. 24
Reset Selection
One mole of any gas at room temperature and pressure will occupy 22.4 liter(s) (option C).
What is an ideal gas?Ideal gas is an hypothetical gas, whose molecules exhibit no interaction, and undergo elastic collision with each other and with the walls of the container.
One mole of an ideal gas contains a volume of 22.414 L at standard temperature and pressure (STP).
According to Avogadro's law, the volume occupied by one mole of a gas must be the same for all gases if the temperature and pressure are the same.
Learn more about ideal gas at: https://brainly.com/question/30236490
#SPJ1
We learned about three career opportunities in the field of pulp and paper in class. Pick one career and find out the education, training, and experience required for this profession. Write about what you found and explain why this profession might interest you
Answer:
Pulp and Paper technology is a specialist field of chemical engineering which involves the study of the processes required for the conversion of raw materials such as wood, into pulp and paper products.
Paper and pulp manufacturing is a growing and dynamic industry so it requires a wide variety of personnel - from unskilled and semi-skilled workers to tradesmen, technicians and engineers - to control all the processes and develop new ones.
I choose to be a chemist in the field of paper and pulp. Requirements and compulsory Subjects: Physical Sciences, Mathematics, Engiineering and Technology.
Chemists are responsible for quality control and they study the influence of various chemicals on pulp and paper. Chemical and mechanical engineers develop new production methods.
I'll like to be a chemist in the field of paper and pulp because they perform the major role in the chemical properties of the paper and pulp.
Explanation:
Hope it helps.
Answer:
PLATO ANSWER
Explanation:
1. Give IUPAC for the following compound
Answer:
Ethane
Explanation:
What is measured by the reaction rate? the probability that a reaction will occur the speed at which products form the time required for a reaction to go to completion
Answer: the speed at which products form
Explanation:
Rate of a reaction is defined as the speed at which a chemical reaction proceeds. It is often expressed in terms of the concentration of a reactant that is consumed in a unit time or the concentration of a product that is formed in a unit of time.
For a general reaction :[tex]A\rightarrow B[/tex]
[tex]Rate=-\frac{d[A]}{dt}[/tex]
or [tex]Rate=+\frac{d[B]}{dt}[/tex]
where d[A] = change in concentration of reactant A
d[B] = change in concentration of product B
dt = time interval
What is the shape of a molecule of CH4?
O A. Trigonal-bipyramidal
O B. Bent
O C. Trigonal-pyramidal
O D. Tetrahedral
Answer:
D. Tetrahedral
Explanation:
the reason is because four electron pairs are distributed.
Calculate the heat of reaction, ∆H°, for the following:
3FeCl2(s) + 4H2O(g) Fe3O4(s) + 6HCl(g) + H2(g)
Answer:
562.76 kJ
Explanation:
∆H° (kJ) is the total of the heats of formation of the products minus the total of the heats of formation of the reactants.
NB: look up the heats of formation of the compounds in the heats of formation reference tables, it is found at the back of most chemistry text
heats of formation of the products (i.e. Fe₃O₄(s) , 6HCl(g) , H₂(g) ) = -1120.9 + 6(-92.3)+ 0 = -1674.7 kJ
heats of formation of the reactants (i.e. 3FeCl₂(s) , 4H₂O(g) ) =3(-423.42) + 4(-241.8) = -2237.46kJ
∆H° = -1674.7 kJ - (-2237.46kJ) =562.76 kJ
Which phrase describes an irregular galaxy?
O has a round shape
O contains many young stars
O has arms that extend from the center
O is larger than other types of galaxies
Answer: The answer would be B. contains many young stars.
Explanation:
There is very little new star formation in Irregular galaxies. Irregular galaxies have no particular shape and are smaller than other types of galaxies.
The irregular galaxy possess many young stars.
Irregular galaxyThey are the most unusual of galaxies.
They do not fit into either the elliptical or spiral galaxy categories.
They do not possess nice spiral arm, however, they do possess dark patches of dust and gas.
The irregular galaxies do not possess definite shape.
They comprise of several young stars as the extent of the formation of stars in irregular galaxies in brisk. They also do comprise old stars.
Thus, the correct statement is contains many young stars.
Find more information about irregular galaxies here:
https://brainly.com/question/1241789
Bee stings release methanoic acid which attacks the nerves in the skin. They can be
neutralized by applying a cream that contains
a) ammonia
b) vitamin C
c) sulphur dioxide
d) acetic acid (vinegar)
Answer:and so an acid should be applied to neutralize them and remove the pain.
Explanation:Bee and Wasp stings can be both painful and itchy, and are very common ... Many common household substances can be used for this, and vinegar and ... If you are near other Bees and Wasps,
Ammonia can be used to neutralise. Hence, option A is correct.
What is methanoic acid?It is the simplest carboxylic acid which consists of a single carboxylic acid group (COOH) which is attached to a hydrogen atom.
Ammonia is a great way to help neutralise the venom of a bee sting. All you need to do is create a thick paste out of baking soda and water and apply it to the sting.
Hence, option A is correct.
Learn more about methanoic acid here:
https://brainly.com/question/10832452
#SPJ2
HELP ME PLZ!!! I really dont know this!!! What characteristic of metals makes them good electrical conductors? -They have mobile protons. -They have mobile valence electrons. -Their crystal structures can be rearranged easily. -They have mobile cations.
Answer:
To have a high electrical conductivity, a normal metal should have mobile valence electrons and a long electron mean free path.
Explanation:
A long mean free path means that the electron goes a long distance between scattering events.
The characteristic of metals which makes them good electrical conductors is that they have mobile valence electrons.
What are the characteristics of metals?
An element is the simplest form of matter.Elements are further classified as metal,non -metals and metalloids. Metals possess luster and are malleable that is they can be drawn into thin sheets.They are also ductile and can be drawn into thin wires and are hard due to the strong ionic bonding present in them.
They are good conductors of electricity and heat as they have valence electrons which are mobile and can be easily be displaced if a current is allowed to pass through the metal, thus making it a good conductor.The conductivity of a metal is directly proportional to the number of valence electrons .
Higher the number of valence electrons, greater is the conductivity.Owing to the valence electrons,current can flow through the metal thus making it a good conductor.
Learn more about characteristics of metals,here:
https://brainly.com/question/1030228
#SPJ6
How many grams of NO are produced from 15.8 g of H2O
Answer:
26.33 g of NO.
Explanation:
We'll begin by writing the balanced equation to produce NO from H2O. This is given below:
5N2 + 6H2O —> 4NH3 + 6NO
Next, we shall determine the mass of H2O that reacted and the mass of NO produced from the balanced equation. This is illustrated below:
Molar mass of H2O = (2x1) + 16 = 18 g/mol
Mass of H2O from the balanced equation = 6 x 18 = 108 g
Molar mass of NO = 14 + 16 = 30 g/mol
Mass of NO from the balanced equation = 6 x 30 = 180 g
From the balanced equation above,
108 g of H2O reacted to produce 180 g of NO.
Finally, we shall determine the mass of NO produced by the reaction of 15.8 g of H2O.
This is illustrated below:
From the balanced equation above,
108 g of H2O reacted to produce 180 g of NO.
Therefore, 15.8 g of H2O will react to produce = (15.8 x 180)/108 = 26.33 g of NO.
Therefore, 26.33 g of NO were obtained from the reaction.
Scientists disagree about the possible effects of global warming. Please select the best answer from the choices provided T F this would be appreciated
Scientific evidence for warming of the climate system is unequivocal.
The current warming trend is of particular significance because most of it is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia.
Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. This body of data, collected over many years, reveals the signals of a changing climate.
The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of many instruments flown by NASA. There is no question that increased levels of greenhouse gases must cause the Earth to warm in response.
Answer:
this is false
Explanation:
Calculate the number of moles in 25.0 g of each of the
following:
a. He
b. 02
c. Al(OH)3
d. Ga S3
e. C4H10, butane
Answer:
A. 6.25moles
B. 0.78moles
C. 0.32moles
D. 0.15moles
E. 0.43moles
Explanation:
use
n = mass/molar massA. He
25/4 = 6.25molesB. O2
25/32 = 0.78molesC. Al(OH)3
27+ 3(17) = 7825/78 = 0.32 molesD. GaS3
70+3(32) = 16625/166 = 0.15molesE. C4H10
4(12)+10(1) =5825/58 = 0.43molesAccording to the mole concept, there are 6.25 moles, 0.78 moles,0.32
moles, 0.15 moles, 0.43 moles.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons.Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.Number of moles=mass/molar mass
Thus, A. He,25/4 = 6.25 moles,B. O₂,25/32 = 0.78 moles,C. Al(OH)₃,25/78 = 0.32 moles,D. GaS₃,25/166 = 0.15 moles E. C₄H₁₀,25/58 = 0.43 moles.
Learn more about moles,here:
https://brainly.com/question/26416088
#SPJ2
At a certain temperature, Ke = 3 for the reaction NO3(g) NO(g) + O2(g) Find the direction of thereaction if at some point in time in a 1.0 vessel the following respective concentrations were measured; [NO] = 2.0 mol/L, [O2] = 1.0 mol/L and NO3(g) = 0.75 mol/L.
Plants can only
cause mechanical weathering.
Please select the best answer from the choices provided
OT
OF
Answer:
Ice wedging, pressure release, plant root growth, and abrasion can all cause mechanical weathering. in the cracks and pores of rocks, the force of its expansion is strong enough to split the rocks apart. This process, which is called ice wedging, can break up huge boulders.
Answer:
f
Explanation:
The common isotopes of carbon are 12C and 13C. The average mass of carbon is 12.01115 amu. What is the abundance of the 13C isotope? A. 1.115% B. 98.885% C. 0.480% D. 99.52% Provide an explanation if possible. Thanks so much!
Answer:
The abundance of the 13C isotope is 1.115%
Explanation:
The given information are;
Common isotope of carbon are 12C and 13C
The formula for calculating the relative atomic mass is the observed mass multiplied by the percentage abundance at that mass given as follows;
M₁ X₁ + M₂X₂ = Relative atomic mass
Where:
X₁ + X₂ = 1 as these are percentage represented as fractions
Let M₁ = 12 for 12C and M₂ = 13 for 13C
X₁ = Relative abundance fraction of 12C
X₂ = Relative abundance fraction of 13C
We have;
12X₁ + 13X₂ = 12.01115.......................(1)
X₁ + X₂ = 1............................................(2)
Which gives;
X₁ = 1 - X₂
Substituting the value for X₁ in equation (1) gives;
12(1 - X₂) + 13X₂ = 12.01115
13X₂ - 12X₂ + 12 = 12.01115
X₂ = 12.01115 - 12 = 0.01115
Therefore, the relative abundance fraction of 13C 0.01115 which in percentage is 100 × 0.01115 = 1.115%.
The pH of a substance can only be determined when it is
a) dried in a powder
b) frozen
c) dissolved in water
d) heated
The pH of a substance can only be determined when it is frozen. Hence, option B is correct.
What is pH?pH stands for Hydrogen potentials.
The use of the pH scale is one practical way of quantitatively determining how acidic something is.
If the pH of a solution is less than 7, it is acidic. If the pH is 7, the solution is neutral and if the pH is greater than 7,the solution is basic.
The pH of a substance can only be determined when it is frozen. Hence, option B is correct.
Learn more about the pH here:
https://brainly.com/question/874715
#SPJ2
Which of the following is a polar molecule?
O A. A carbon monoxide molecule (CO)
OB. A linear carbon dioxide molecule (CO2)
OC. A calcium oxide molecule (Cao)
O D. An oxygen molecule (0)
Answer:
D. An oxygen molecule (0)
Explanation:
Hope it helps.