Answer:
In order to take steps by humans for controlling the change in climate.
Explanation:
It is important that scientist find out the change which occurs in the climate with the passage of time by performing experiments and also repeat the experiments in order to verify their findings. Due to these experiments, scientists also find out the reasons behind of climate change which enable us to take steps in preventing the change that occurs in the environment. it is also important for scientists to be able to explain how they know that climate has changed over time in order to explain that he is not assuming or making predictions, he has to provide evidence for his statement which is only be possible through experiments.
Give two examples of solutions that you might find or prepare in a kitchen.
Explanation:
solid liquid
solid gas
liquid solid
which substance will form a solution when mixed with liquid benzene (c6h6)
Answer: [tex]I_{2} (l)[/tex]
Explanation: Because C 6 H 6 is nonpolar substance and I 2 is also nonpolar compound
According to the concept of solubility,iodine will form a solution when mixed with liquid benzene as both are non-polar substances.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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Distillation is a _____________ separation technique.
chemical
physical
Answer:
Chemical
Explanation:
Because it's being done by chemical means
What is the molarity of a solution that contains 2 moles of KCl in 4 L of solution? a 2.0 M b 0.5 M c 0.25 M d 8.0 M
Answer:
A.) 2.0 M
Explanation:
Molarity=mole of solutes/Liters of solution so M=mol/L
2moles/4 L =2 M
Which represents the greatest time frame in which a short-term environmental change can occur?
in days
O in minutes
O over hundreds of years
O over thousands of years
Answer:
in days
Explanation:
A short term environmental change refers to changes in the environment that happens within a short period of time, for example, flooding, drought, volcanic eruptions etc. In contrast to short term environmental change, long term environmental change takes place over a long period of time hence species have a longer time to adapt to it. Short term environmental changes may or may not be caused by humans. An example of a short term environmental change caused by humans is oil spillage. Short term environmental changes may lead to the the migration of species from the ecosystem.
Short term environmental changes usually occur within a very short time. The greatest time frame in which a short term environmental change can occur is in a matter of days. Only longterm environmental changes span hundreds and thousands of years.
Answer:
it is c
Explanation:
i took the test :)
PLEASE HELP CHEM BABES I HAVE BEEN CRYING FOR A WHILE NOW
1. Calculate the mass of nitrogen dioxide (NO2) present in a 0.831 L container if the pressure is 100 kPa at a temperature of 27 oC. R = 8.31 kPa x L / mol x K. (K = oC + 273).
2. A 33.2 L tank contains 280 g of compressed helium. If the pressure inside the tank is 700.0 kPa, what is the temperature of the compressed gas? You must convert the mass of helium into moles using the molar mass of He. The conversion factor will be 1 mol / molar mass of helium. R = 8.31 kPa x L / mol x K
Answer: See below
Explanation:
1. To calculate the mass, you know you can convert by using molar mass. Since mass is in grams, we can use molar mass to convert moles to grams. This calls for the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We manipulate the equation so that we are solving for moles, then convert moles to grams.
n=PV/RT
P= 100 kPa
V= 0.831 L
R= 8.31 kPa*L/mol*K
T= 27°C+273= 300 K
Now that we have our values listed, we can plug in to find moles.
[tex]n=\frac{(100kPa)(0.831L)}{(8.31kPa*l/molK)(300K)}[/tex]
[tex]n=0.033mol[/tex]
We use the molar mass of NO₂ to find grams.
[tex]0.033mol*\frac{46.005g}{1mol }=1.52 g[/tex]
The mass is 1.52 g.
2. To calculate the temperature, we need to use the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We can manipulate the equation so that we are solving for temperature.
T=PV/nR
P= 700.0 kPa
V= 33.2 L
R= 8.31 kPa*L/mol*K
n= 70 mol
Now that we have our values, we can plug in and solve for temperature.
[tex]T=\frac{(700kPa)(33.2L)}{(70mol)(8.31 kPa*L/molK)}[/tex]
[tex]T=40K[/tex]
The temperature is 40 K.
What is the molarity of a solution prepared by dissolving 7.0 moles of NaCl solute in 585 ml of solution
?
Answer:
12 mol/L
Explanation:
Molarity = moles/L solution = 7.0 mol /0.585 L ≈ 12 mol/L
True Or False? A Load In A Circuit Transforms Light Energy Into Electrical Energy
Answer:
False
Explanation:
This is because the electrical circuit, where the electrical energy is converted into another form of energy, e.g. lightbulb converts electrical energy into light and heat, an electric bell converts the electrical energy into sound and heat.
False.
The statement a load in a circuit transforms the light energy into electrical energy is False.
What is a load in the circuit?Any device which transforms the electrical energy into other forms of energy, like light energy, sound energy, etc is called an electric load in the circuit.
What is electrical energy?The type of kinetic energy caused by moving electric charges is known as electrical energy. The alternating current, direct current, and batteries provide electrical energy.
So, the load transforms the electrical energy into other forms like light energy, sound energy, etc.
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In the lab, a student adds 4.5 g of sodium chloride (NaCl) to 100.0 g of water. Calculate the molality of the solution.
Answer:
0.77mol/Kg.
Explanation:
The following data were obtained from the question:
Mass of NaCl = 4.5g
Mass of water = 100g.
Molality =...?
Next, we shall determine the number of mole in 4.5g of NaCl. This can be obtained as follow:
Mass of NaCl = 4g.
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of mole NaCl =..?
Mole = Mass /Molar Mass
Number of mole of NaCl = 4.5/58.5
Number of mole of NaCl = 0.077 mole.
Next, we shall convert 100g of water to kilograms. This is illustrated below:
1000g = 1kg
Therefore, 100g = 100/1000 = 0.1Kg.
Finally, we can determine the molality of the solution as follow:
Molality is simply defined as the mole of solute per unit kilogram of solvent (water). Mathematically, it is represented as:
Molarity = mole of solute / kg of solvent
Mole of solute, NaCl = 0.077 mole
Kg of solvent = 0.1kg
Molality = 0.077mol/0.1kg
Molality = 0.77mol/Kg
The molarity of the solution is 0.77mol/Kg.
Calculation of the molarity of the solution:
Since
Mass of NaCl = 4.5g
Mass of water = 100g.
Here,
Mass of NaCl = 4g.
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Now
Mole = Mass /Molar Mass
= 4.5/58.5
= 0.077 mole.
Now
1000g = 1kg
So,
100g = 100/1000 = 0.1Kg.
Now
Molarity = mole of solute / kg of solvent
Mole of solute, NaCl = 0.077 mole
Kg of solvent = 0.1kg
So,
Molality = 0.077mol/0.1kg
= 0.77mol/Kg
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Element X is a solid that is brittle, lacks luster,and has six valence electrons. In which group on the Periodic Table would element X be found
Answer:
Sulfur?
Explanation:
Sulfur has 6 valence electrons and does not have luster.
How many moles of sodium hydroxide would react with 1 Mole of sulphuric acid?
Answer:
Two moles.
Explanation:
Sulphuric (sulfuric) acid [tex]\rm H_2SO_4[/tex] is a diprotic acid. When one mole of [tex]\rm H_2SO_4[/tex] molecules dissolve in water, two moles of [tex]\rm H^{+}[/tex] ions would be produced.
[tex]\rm H_2SO_4 \to 2\, H^{+} + {SO_4}^{2-}[/tex].
On the other hand, sodium hydroxide [tex]\rm NaOH[/tex] is a monoprotic base. When one mole of [tex]\rm NaOH[/tex] formula units dissolve in water, only one mole of hydroxide ions [tex]\rm OH^{-}[/tex] would be produced.
[tex]\rm NaOH \to Na^{+} + OH^{-}[/tex].
Note that [tex]\rm H^{+}[/tex] and [tex]\rm OH^{-}[/tex] react at a one-to-one ratio:
[tex]\rm H^{+} + OH^{-} \to H_2O[/tex].
As a result, it would take [tex]2\; \rm mol[/tex] of [tex]\rm OH^{-}[/tex] to react with the [tex]\rm 2\; mol[/tex] of [tex]\rm H^{+}[/tex] that was released when [tex]1\; \rm mol[/tex] of [tex]\rm H_2SO_4[/tex] is dissolved in water. Since one mole of [tex]\rm NaOH[/tex] formula units could produce only one mole of [tex]\rm OH^{-}[/tex], it would take [tex]\rm 2\; mol[/tex] of [tex]\rm NaOH[/tex] formula units to produce that [tex]2\; \rm mol[/tex] of [tex]\rm OH^{-}[/tex] for reacting with [tex]1\; \rm mol[/tex] of [tex]\rm H_2SO_4[/tex].
A.
B.
C.
D.
what’s the correct answer?
Answer:
C Gamma Rays
Explanation:
Radio waves, on the other hand, have the lowest energies, longest wavelengths, and lowest frequencies of any type of EM radiation. In order from highest to lowest energy, the sections of the EM spectrum are named: *gamma rays* ,X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves.
) What is the definition of an enzyme? A.Enzymes are carbohydrate molecules that act as catalysts to speed up chemical reactions in living things. B.Enzymes are polymer molecules that act as catalysts to slow down chemical reactions in living things. C.Enzymes are protein molecules that act as catalysts to speed up chemical reactions in living things. D.Enzymes are fat molecules that act as catalysts to speed up chemical reactions in living things. E.Enzymes are protein molecules that act as catalysts to slow down chemical reactions in living things.
Answer:
option c
enzymes are protein molecules that act as catalysts to speed up bio chemical reactions
Calculate the Molarity of a 0.23 mole solution of sucrose, C 12 H 22 O 11 that is dissolved in 5 liters of water.
Answer:
0.046 M
Explanation:
Molarity = mol solute/ L solution = 0.23 mol/ 5 L = 0.046 mol/L = 0.046 M
scientists often work on projects for a long time and fail to see sources of error in their research. Which process allows an outside expert to look at the scientist’s project and point to sources of error?
Answer:
Replication
Explanation:
In science, the work of a scientist is regarded as authentic if other experts in other places can follow the same steps as he/she claimed to follow and arrive at the same result.
For example, a scientist in California, United States of America may carry out a research and publish his findings. Another scientist in Christchurch New Zealand following exactly the same procedure is expected to arrive at the same results as the original researcher if there were no errors in the work.
However, where there are disparities in results, the scientist in Newzealand may discover errors that were unknown to the original researcher in the united States. The New Zealand scientist was carrying out a process known as 'replication'. That is, repeating a scientific research in order to obtain the same results thereby validating the research.
How would you separate pure dry cleaning solvent from waste dry cleaning solvent containing dirt that dissolves in the solvent from clothes
Answer:
fddff s
Explanation:
v c dggbgzfx
Which phrase describes a feature of a Mercator projection? is least commonly used sizes most features to scale presents longitude lines as parallel shows most accurately near the prime meridian
QUICK
Answer:
presents longitude lines as parallel
Explanation:
The Mercator projection shows longitude lines as parallel, hence greatly distorts sizes and distances near the poles. A useful feature is that a course of constant bearing shows as a straight line.
Answer:
C.) presents longitude lines as parallel
Explanation:
Took it on E2020
example of potassium salt
Answer:
1) Sodium Chloride
2) Potassium Dichromate
3)Calcium Chloride
4)Sodium Bisulfate
Explanation:
Ex:1) Sodium chloride (NaCl) is the most common type of salt in our lives. Known as table salt, it forms a cubic lattice when it's in solid form. It's one of the safest materials you can use in a chemistry class or kitchen.
Ex:2) Potassium dichromate (K2Cr2O7) is an orange-colored salt composed of potassium, chromium and oxygen. Not only is it toxic to humans, it's also an oxidizer that is a fire hazard. Potassium dichromate should never be thrown away. Instead, it should be washed down the drain with a lot of water. Always use rubber gloves when working with this compound. If you spill a potassium dichromate solution on your skin, it gives you a chemical burn. Keep in mind that any compound with chromium in it is a potential carcinogen.
Ex:3)Calcium chloride (CaCl2) resembles table salt in its white color. It is widely used to remove ice from roads. It's more effective than sodium chloride as a deicer, because calcium chloride produces three ions, while calcium chloride produces only two. Calcium chloride can melt ice down to minus 25 F, as much as 10 degrees lower than for sodium chloride. Calcium chloride is so hygroscopic, which is the ability to absorb water, that if you leave it in a room uncovered, it can absorb enough water from the air to dissolve into a solution all on its own.
Ex:4) Sodium bisulfate (NaHSO4) forms from sodium, hydrogen, sulfur and oxygen. It is created from sulphuric acid and retains one of the acid's hydrogen ions, which gives this salt acidic qualities. Known as a dry acid, sodium bisulfate is used in commercial applications, such as reducing the pH level of spas and swimming pools, washing concrete and cleaning metals. In its solid form, sodium bisulfate forms white beads. This salt is poisonous and can damage your skin, so use rubber gloves when handling it. If ingested, call the poison control center immediately and do not induce vomiting.
MY ELEMENT IS SODIUM
1. Summarize the physical and chemical properties of the element you selected.
2. In the lesson, many models were used to depict the atom. How did these models help you understand atomic structure?
3. How do protons, neutrons, and electrons differ in terms of their electrical charges and locations within the atom?
4. Describe the four fundamental forces. Which of these forces are involved in chemical bonding?
Please answer these questions or at least one.
Answer:
Explanation:
1. The element you selected is Sodium. some of the physical properties are
i. Sodium has a strong metallic lustre
ii. Sodium are usually silver white in color
iii. Sodium is soft it can be cut with knife
iv. Sodium are malleable and ductile.
v. Sodium conduct electricity
Sodium belong to group 1 elements which are called Alkali metals. Sodium have one valency electron and it gives this electron easily during bonding . This is one reason sodium and other alkali metals are very reactive. Sodium can instantly be oxidized by water. Sodium has a relative atomic mass of approximately 23 amu.
2. There are various models that describe atoms .This models includes John Dalton models, J.J Thompson model, Ernest Rutherford model, Bohr's models etc. This models made us understand the role and location of each sub atomic particles. The models shed more light on subatomic particles like electron which revolve around the nucleus. It provide more information on what contribute to the weight of an atom.
3. The proton , neutron and electron are subatomic particles of an atom. The proton and the neutron are located at the nucleus of an atom. The proton and neutron contributes majorly to the weight of an atom. The proton is positively charge while neutron has no charge.
Electron is found to move around the nucleus in cloud. The electron is negatively charge. The electron determines bonding of atoms. An atom is electrically neutral if the number of proton is equal to the number of electron.
4. The four fundamental forces includes weak nuclear forces , strong nuclear forces , gravity and electromagnetic forces.
Weak nuclear forces is responsible for particle decay .Nuclear forces don't play a role in chemical reaction . If they are involve in a reaction it becomes nuclear reaction not chemical reaction.
Strong nuclear forces causes a strong nuclear interaction and it is the strongest among the 4 fundamental forces. This strong force only operate when subatomic particles are much closer to each other.
Gravity force is too weak to affect chemical reaction much. The gravity forces involves the interaction between two objects with energy and mass.
The electromagnetic force act between charged particles like negatively charged electron and positively charged proton. Electromagnetic force is the most important force in chemical bonding as it depends on the arrangement of atoms and the state of their electron. Electromagnetic forces exist in various forms like the covalent bond, metallic, ionic , dipole dipole, hydrogen bonds and many more. The major force involve in chemical bonding is the electromagnetic force.
3. Sugar solution(sugar + water) is a homogeneous mixture and sugar can be separated from water through evaporation .Comment.
Plz, answer
Answer:
water is the answer
Explanation:
The sugar and water mix to make sweet water but the sun extracts the sugar from the water leaving only normal water
Answer:
water can be evaporated
Explanation:
the water will be evaporated leaving only the sugar residue behind.
what is the difference between an exothermic and endothermic reaction.
Answer:
An endothermic reaction takes in heat, but feels cold to the touch. An exothermic reaction gives off heat and feels warm to the touch because it is heating the outside objects.
Predict your observation if a magnesium ribbon is put in potassium hydroxide solution and tested with a lighted wooden splinter.
mg reacts with the acid and produce visible bubbles of hydrogen gas. they will produce audible pops as the hydrogen ignites. ... Hydrochloric acid is a corrosive liquid. Hydrogen gas is explosive.
Which statement accurately describes the movement of Earth’s plates due to convection currents?
Answer:
Volcanic eruptions.
pls help asap pls !!
Answer:
basic solution.
Explanation:
has a pH of 12.
it turns clear indicator pink.
it contains hydroxide ions which conduct electricity
What are the two ways that humans lose heat? PLS help thank you!
Answer:
Evaporation, Radiation
Explanation:
Evaporation of water from your skin if it is wet (sweating). ...
Radiation (similar to heat leaving a woodstove).
What shape would a molecule with two bound groups and two lone pairs
have?
A. Trigonal pyramidal
B. Tetrahedral
C. Linear
D. Bent
Answer:
It would have to be D, a bent shape
Explanation:
I just took the quiz
How many electrons must calcium lose to satisfy the octet rule?
Gain 2 electrons
Lose 2 electrons
Lose 40 electrons
Lose 20 electrons
• Previous
Next >
Answer:
Lose 2 electrons
Explanation:
An acid is added to water, and a new equilibrium is established. What is the system after the acid is added? A. pH w = 1 x 10-14 B. pH w -14 C. pH > pOH and Kw = 1 x 10-14 D. pH > pOH and Kw > 1 x 10-14
Answer:
C. pH > pOH; Kw = 1.0 * 10^-14
Explanation:
The ion product of water, Kw = [H+]*[OH-] = 1.0 * 10^-14. It is a constant.
When an acid or base is added to water, its ion product does not change as it a constant. However, the relative concentrations of H+ ions and OH- ions will change depending on whether an acid or base is added to water.
When an acid is added to water, the concentration of H+ ions increases while that of OH- ions decreases, and vice versa.
Therefore, in the above situation where an acid is added to water, pH > pOH; Kw = 1.0 * 10^-14
Which of the following statements is true? Less rain and snow falls in smoky areas than in other areas. Acid rain causes corrision of buildings and statues. The first laws againts pollution were passed in the 1990s. Cars are the leading cause of nitrogen oxide pollution.
Answer:
Acid rain causes corrosion in buildings.
Explanation:
This is true because acid rain over time can eat away at the building.
calculate the ph of a solution containing 0.001 mol dm-3 Naoh
Answer:
pOH = - log [molarity of OH-] = - log [ molarity of NaOH] , assuming full dissociation. Thus, pOH = - log ( 0.001) = - (-3) = 3. Thus, the pH of 0.001 mol/dm3 NaOH solution is 11.
Explanation:
Hope it'll help!