But pH is quite an important measurement of water. Maybe for a science project in school you took the pH of water samples in a chemistry class ... and here at the U.S. Geological Survey we take a pH measurement whenever water is studied. Not only does the pH of a stream affect organisms living in the water, a changing pH in a stream can be an indicator of increasing pollution or some other environmental factor
How many molecules are in a 189 g sample of carbon tetrabromide, CBr4?
Chemical A and Chemical B react in an exothermic reaction. What can be known about what will happen when Chemical A and Chemical B are mixed together?
Please help. I'm confused.
UCI Chemistry researchers, Prof. F. Sherwood Rowland and Dr. Mario Molina werefirst to discovered in 1973 that chlorofluorocarbons (CFCs) were depleting the Earth’sozone layer when released into the atmosphere. Once they reach the stratosphere, Clis released from the CFCs molecules by interaction with UV light. Free Cl atoms areable to react with ozone in a catalytic cycle that converts O3into the more stable O2.It is estimated that a single Cl atom is able to react with∼100000 O3molecules.Although CFCs production was banned in 1996, there are still a substantial numberof motor vehicle air conditioners (MVACs) that use CFC-12 (CF2Cl2) as refrigerant.The average CFC-12 emission rate from operating MVACs has been estimated tobe 59.5 mg per hour per vehicle (Zhang et al.Environ. Sci. Technol. Lett.2017).How much chlorine, in kg, is added to the atmosphere in a year due to 100 millionMVACs using CFC-12 as refrigerant?
Answer:
15.27895 x 10⁶kg of chlorine radical is added to the atmosphere in a year due to 100 million MVACs
Explanation:
Chlorofluorocarbons (CF₂Cl₂) from refrigerants produce chlorine radicals according to the following equation
CF₂Cl₂ → CF2Cl + Cl ⁻ .........(1)
From equation 1, one mole of CF₂Cl₂ produces one mole of Chlorine radical
From the question,
The emission rate of CF₂Cl₂ is 59.5mg/hour/MVAC
In one day the emission rate would be 59.5 x 24hours
= 1428mg/day
In one year, the emission rate would be 1428mg/day x 365days
= 521220mg/year
= 521.220g/year/MVAC
Therefore the emission rate for 100 million MVAC using CF₂CL₂ in a year is
= 52122 x 10⁶g/year/MVAC
= 52122 x 10³kg/year/MVAC
The molar mass of CF₂CL₂ = 120.913g/mol
No of moles of CF₂CL₂ = mass/ molar mass
= 52122 x 10⁶g / 120.913g/mol
= 431 x 10⁶ moles of CF₂Cl₂
From equation 1, since one mole of CF₂Cl₂ produces one mole of Chlorine radical, it implies that
431 x 10⁶ moles of CF₂Cl₂ would produce 431 x 10⁶ moles of chlorine radical,
Therefore, to find the mass of chlorine radical produced, we use the formula
No of moles of chlorine radical = mass/ molar mass
431 x10⁶ moles = mass of chlorine radical /molar mass of chlorine radical
431 x 10⁶ moles = mass/ 35.45g/mol
mass of chlorine = 431 x 10⁶ moles x 35.45 g/mol
= 15278.95 x 10⁶ g
In Kg, the mass = 15,278.95 x 10³kg of cholrine radical
= 15.27895 x 10⁶ Kg of chlorine radical
Mendelee's periodic table was organized by
Answer:
Mendeleev arranged the elements in order of increasing relative atomic mass . When he did this he noted that the chemical properties of the elements and their compounds showed a periodic trend .
Explanation:
Hope this helps!! Please consider marking brainliest! Have a good one!!Almost all of Earth's atmosphere is created through the process of photosynthesis.
True
False
Answer:
False
Explanation:
This chemical equation represents a chemical reaction.
NaCN + HBr + NaBr + HCN
Which two chemicals are reactants in the chemical reaction?
A.NaCN
B.NaBr
C.HCN
D.HBr
Answer: NaCN and HBr
Explanation:
When 21.5 g of CH4 gas reacts with 387.5 g O2 gas, how much CO2 is formed?
Answer:
Mass = 58.96 g
Explanation:
Given data:
Mass of CH₄ = 21.5 g
Mass of O₂ = 387.5 g
Mass of CO₂ formed = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of CH₄:
Number of moles = mass / molar mass
Number of moles = 21.5 g/ 16 g/mol
Number of moles = 1.34 mol
Number of moles of O₂ :
Number of moles = mass / molar mass
Number of moles = 387.5 g/ 32 g/mol
Number of moles = 12.1 mol
now we will compare the moles of CO₂ with O₂ and CH₄.
O₂ : CO₂
2 : 1
12.1 : 1/2×12.1 = 6.05 mol
CH₄ : CO₂
1 : 1
1.34 : 1.34
Number of moles of CO₂ produced by CH₄ are less thus it will limiting reactant.
Mass of CO₂:
Mass = number of moles × molar mass
Mass = 1.34 mol × 44 g/mol
Mass = 58.96 g
when temperature increase gas decrease or increase support u r answer with daily life example
Answer:
increase
Explanation:
dont known reason burr answer is correct
Answer:
When temperature increases ,gas increases ,because of the rise in temperature evaporation will take place.
Explanation:
When you boil water to make coffee/tea the kettle/boiler releases the evaporation caused by the rise in temperature.
which of the nonmetals is the least reactive?
a) Ne
b) O
c) Cl
d) F
Flourine
Explanation:
The element F has a high negative (ΔeqHө) but not so high IE1 . Therefore, it is the least reactive non-metal.
Which scientist is known for developing the planetary model of the atom
Answer:
Ernest Rutherford
Explanation:
The Rutherford model, proposed originally in 1911, dipicts a planetary model of the atom in which there is a nucleus and electrons circling it.
Answer:
Niels Bohr
Explanation:
Suppose you want to make 2000g of a solution of glucose in water that has
2.8% (m/m) concentration. How much glucose should you use?
Answer:
56 g of glucose
Explanation:
We can find the mass of glucose used as follows:
[tex] \%_{m/m} = \frac{m_{s}}{m_{sol}}\times 100 [/tex] (1)
Where:
[tex]m_{s}[/tex] is the solute's mass =?
[tex]m_{sol}[/tex] is the solution's mass = 2000 g
% (m/m)= 2.8 %
By solving equation (1) for [tex]m_{s}[/tex] we have:
[tex] m_{s} = \frac{\%_{m/m}*m_{sol}}{100} = \frac{2.8*2000 g}{100} = 56 g [/tex]
Therefore, you used 56 g of glucose to make 2000 g of a solution of glucose in water.
I hope it helps you!
Need help fast please I am timed and giving 47 points.
Four groups of students plan scientific investigations to answer four questions for the science fair.
Questions for Science Fair:
1-What kinds of plant life grow naturally in the town parks?
2-Which types of treats do different breeds of dogs like best?
3-Do different types of grass affect how far a ball rolls?
4-How are the chemicals in different vegetables similar?
Which question would most likely be answered with an experimental investigation?
A-1
B-2
C-2
D-4
Answer:
C
Explanation:
Answer:
C - 3
Explanation:
This can be actually tested
Can you think of other solutions that might be
acidic?
Answer:
i think the answer is yess
Answer:
Limes, Lemons, Vinegar, Stomach acid, Batteries, Sour Candy, etc.
Nitric Acid, Chloric Acid, Carbonic Acid, Citric Acid, Perchloric Acid, Flouric Acid, etc.
Hope this helps!
Explanation:
What is the total number of electrons in As-3?
Answer:
Arsenic, As, has atomic number 33, which is the number of protons in the nuclei of its atoms. A neutral As atom would also have 33 electrons. The electron configuration of a neutral arsenic atom is [Ar]3d104s24p3
Explanation:
Label B-L in the diagram below
Answer:
B. Polar Easterlies
C. Sub polar low
D. Prevailing westerlies
E. Sub tropical high
F. Tropical easterlies
G. Inter tropical convergence zone
H. Tropical easterlies
I. Sub tropical high
J. Prevailing westerlies
K. Sub polar low
L. Polar easterlies
Explanation:
n the Bohr model of an atom (shown), protons are represented in blue, the neutrons are red and the electrons are green. Use your periodic table and determine which of the following atoms is represented by the Bohr model.
Answer: B
Explanation: Valence electrons are the number of electrons out the outermost shell of the diagram. In this diagram, there is one valence electron. This means that it is highly reactive since the shell is not complete and needs other elements to be able to complete the outermost shell. If this model had a full outermost shell, then it would not be reactive (noble gases).
Answer: B
Explanation:This test it anoying.
A scientist that studies wind movement should know about________ which helps predict where global winds will go. *
if u get it right i will give u brainliest
Types of fronts
Temperature differences on Earth
Types of breezes
The water cycle
Answer:
Types of fronts because meteorologists are able to predict the weather by the looking at the air mass (fronts) in the atmosphere.
Answer:
Types of fronts
Explanation:
Which on, help me please, WILL BE MARKED AS BRAINLEST
Answer:
b and c
Explanation:
Because in a chemical change in order for a substance or matter to change shape it needs to either heat up or cool down
What forces are present in this situation?
An elevator is rising at a constant speed; the elevator is the object in this situation.
A.gravity and tension
B.normal,gravity,and tension
C.normal and tension
D.gravity
Answer:
A. Gravity and Tension
Explanation:
Gravity and Tension would be the only things changing the rising speed of the elevator.
Normal makes no sense not sure why that is an answer.
Gravity effects how much Tension is pulling on the elevator to go down while the elevator is pushing up.
Let me know if you have any other questions.
What causes uneven heating on Earth? *
Temperature Differences
Earth's Rotation
Earth's Revolution
Global Wind System
if u get it right i will give brainliest
Answer:
temperature differences
Explanation:
Solar heating of the Earth's surface is uneven because land heats faster than water, and this causes air to warm, expand and rise over land while it cools and sinks over the cooler water surfaces. ... Wind is the result of pressure changes in the atmosphere.
Shanika is an engineer at an amusement park who is experimenting with changes to the setup for a magnetic roller coaster ride. In one ride, there are two identical roller coaster cars (orange and green) that start on opposite sides of a large magnet located at the center of a station. Shanika wants to get the largest increase in potential energy she can by moving one car one space to the left or the right. Shanika can move the orange car to point A or point B, or she can move the green car to point C or point D. Which movement should she make? Why will that movement result in the largest increase in potential energy? Describe the magnetic force that will act on the roller coaster car she moves.
Answer:
Shanika should move the orange coaster car to point B. This movement will result in the largest increase in potential energy. This is because the carts are repelling, which means to increase the potential energy you have to go against the magnetic field. Because the carts are being repelled from the centre magnet to go against the magnetic field you would move the cart closer to the magnet. In this case, moving the orange cart to point b would increase the potential energy greater than any other move.
Explanation:
what i meant in the last sentence was that moving the orange cart to b (closer to centre magnet) would end in a greater potential energy change than moving the other, green, cart closer. This is because of the distances between the carts and the centre magnet. Potential energy does not increase linearly meaning that if a cart is one cart is an inch away from the magnet and another is a foot, if you moved both magnets a cm closer to the centre magnet the one an inch away would have a larger potential energy change.
Atoms can gain, lose, or share
electrons during a chemical change. Why
doesn't this cause the atoms identities to
change?
Answer:
Atoms can gain, lose, or share electrons during a chemical change. Chemical changes do not affect the nucleus of an atom. For this reason, an atom has the ability to retain its properties or identity even if the number of electrons is different. Therefore, the atom's identity won't change.
Explanation:
The outer shell of this element was determined as illustrated here.
It must be a _____.
Which of the following atoms has the largest radius
F
I
Cl
Br
Answer:
francium
Explanation:
Atomic radii bary in a predictable across the periodic table.
The atomic radius elements increases down a group. Hence in the halogen group the last element in the group that is I have the largest radius.
What is atomic radius?Atomic radius is the distance is the distance from the nucleus to the valence orbital. The atomic radius depends on the electronegativity and number of electrons in the atom.
In periodic table, atomic radius decreases from left to right because, the electronegativity that is the ability of atomic nucleus to attracts its electron increases and thereby the atoms shrinks.
Down a group the number of shells increases and thereby electrons are more screened from the nuclear attractive pulling. Therefore in the group from fluorine, chlorine, bromine and iodine, iodine has the less electronegativity and thus largest radius.
To find more on atomic radius, refer here:
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How do You Think the radius of an atom will change as you move down a Group (Vertical Column) in the periodic table
Answer:
As you move left to right, the atomic radius gets SMALLER, so atoms hold on to their electrons more tightly and are more reactive. As you move down a group, the atomic radius gets LARGER, so atoms have a weaker hold on their electrons and are less reactive
Explanation:
if this answer is correct make me as brainlelist
The fuel tank of an airplane has a device that measures the fuels temperture . Befire tge airplane took off the tenoerature of the fuel was 27 degree c . After the airplane had been flyinf gor one hour the tempertaure of the fuel had decreased to 2 degree c. Which of the follwoing must have happend to moluses in the fuel
Answer:
This question is incomplete
Explanation:
This question is incomplete. However, Jet fuels are produced/designed in such a way that they can absorb cold and become as cold as -47 °C; this is because of the cold temperature in which the jet flies. When the fuel absorbs this coldness, the movement of the molecules in the fuel begins to reduce (just like in every other substance undergoing coolness) and keeps reducing as the temperature keeps dropping. Ordinarily, if this temperature reduces to a particular point (freezing point), the movement of the molecules will stop totally leading to the fuel solidifying/freezing (which has happened sometime before the production of more improved fuel with lower temperature that is been used now).
NOTE: There are some perceived spelling errors in the question. For example, it appears the "moluses" is actually "molecules", "befire tge" is "before the" and "tenoerature" is "temperature".
Answer:
B. Took the test lol
Explanation:
hope this helps
In which of the following situations is a plant reproducing sexually?
Answer:
(ANSWER CHOICES ORDER MAY BE DIFFERENT FROM YOURS!!)
A.
The pollen from one flower is transported by an insect to the ovule of another flower.
B.
A potato plant produces a tuber, and the next year, a new plant grows from the tuber.
C.
Part of the stem segment of a cactus plant falls off and begins to form a new plant.
D.
A new shoot emerges from a strawberry plant and produces another plant.
Explanation:
It's "The pollen from one flower is transported by an insect to the ovule of another flower. " because i got it from study island
YALL can you please answer this
Write a balanced chemical equation for the reaction that occurs when calcium metal undergoes a combination reaction with O2(g).
Answer:
CaO[tex]_{s}[/tex]
Explanation:
The chemical reactants are;
Calcium metal = Ca[tex]_{s}[/tex]
Oxygen gas = O₂[tex]_{g}[/tex]
Now let us write the reaction:
2Ca[tex]_{s}[/tex] + O₂[tex]_{g}[/tex] → 2CaO[tex]_{s}[/tex]
The product is CaO in solid form.
This reaction is a combination or synthesis reaction in which two substances combine to give a single product.
What determines the strength of a dipole-dipole force?
A. The more symmetrical the molecule, the stronger the force.
B. The more hydrogen in the molecule, the stronger the force.
C. The more polar the molecules, the stronger the force.
D. The larger the atomic radius, the stronger the force.
The more polar the molecules, the stronger the force. Hence, option C is correct.
What is dipole-dipole force?Dipole-Dipole forces are the interaction between molecules of the permanent dipole. It occurs between the partially charged positive molecules and partially charged negative molecules.
Polar molecules align themselves so that the δ– end of one molecule is near the δ+ ends of other molecules.
The molecules are thus attracted to each other. Dipole-dipole forces exist between polar molecules.
The greater the polarity, the stronger the dipole-dipole forces.
Hence, option C is correct.
Learn more about dipole-dipole force here:
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Which is a direct result of increased consumption of metals?
rising sea levels
climate change from the use of metals
pollution from mining operations
increased human population
Answer:
Answers:Pollution from mining operations.
A direct result of increased consumption of metals is: C. pollution from mining operations.
Mining can be defined as a process through which minerals and metals are excavated from the planet Earth, especially from a reef, vein, seam, lode or an ore body.
Generally, the above process (mining) results in the pollution of the environment.
Pollution can be defined as the physical degradation (contamination) of the environment through an emission of pollutants or waste materials.
Some examples of pollutants or waste materials that are found in different parts of the world are;
Ozone.Nitrogen dioxide.Particulate matter.Sulphur dioxide.Carbon monoxide.Lead.In conclusion, pollution from mining operations is mainly as a result of an increased consumption of metals such as lead, tin, etc. because of the degrading processes associated with them.
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