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 :)
In which kingdom do all organisms have cells that lack a cell wall?
fungsi
plants
animals
bacteria
Answer:
The answer is animals
Explanation:
Plants and fungi have a cell wall, and although most bacteria lack a cell wall, the question is asking in which kingdom do ALL organisms lack a cell wall. Hope this helps.
Answer:Bacteria
Explanation:
metallic pan is provided with a wooden plastic handle give reason
The metallic pan iis most likely going to be used on a stove.
The stove is heating something, and the conductive metallic pan will, well, conduct that heat throughout the entire body of the pan. Doing this will spread the heat to the handle, burning your hands.
Both wood and plastic are insulators, and they do not conduct heat or electricity. They will insulate your hands and protect them from the heat.
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.
You have nitrogen gas (N2) at a pressure of 0.5 atm, a volume of 25000 mL, and a temperature of 300 K, how many grams of nitrogen are present?
Answer:
About 7.109g
Explanation:
25000mL is the same as 25 liters.
[tex]PV=nRT \\\\0.5 (25)=n (0.0821) (300) \\\\n\approx 0.508[/tex]
Multiplying this by the molar mass of nitrogen, you get about 7.109 grams of nitrogen. Hope this helps!
What is the chemical name of the covalent compound P4O9? A. tetraphosphorus nonaoxygen B. tetraphosphate nonoxygen C. tetraphosphide nonaoxide D. tetraphosphorus nonoxides.
Answer: The chemical name of the covalent compound [tex]P_4O_9[/tex] is, tetraphosphorous nonaoxide.
Explanation:
A covalent compound is a compound where the sharing of electrons takes place between elements where both the elements are non-metals.
The naming of covalent compound is given by:
1. The less electronegative element is written first.
2. The more electronegative element is written second. Then a suffix is added with it. The suffix added is '-ide'.
3. If atoms of an element is greater than 1, then prefixes are added which are 'mono' for 1 atom, 'di' for 2 atoms, 'tri' for 3 atoms and so on.
Hence, the correct name for the compound [tex]P_4O_9[/tex] which is a covalent compound is, tetraphosphorous nonaoxide.
Which evidence would most strongly indicate that a chemical change is
taking place?
A. Fizzing
B. Changing shape
C. Breaking
D. Changing state
Please help me with those questions please
Answer:
I know the answer to 5, i think
Explanation:
No, if both parents were left-handed, they would not have to be left-handedis bleached water safe for drinking???
Answer:
NO most of the time
Explanation:
I hope this is for school and not personal reasons. Bleach will kill you if drank plain, if it's diluted a little it may not be fatal but can still greatly harm your organs. If it is diluted extremely it is used for cleaning tap water and is perfectly fine.
Just to be on the safe side, I want you to know there is always help, and if you need someone to talk or text this is the number for the National Su1c1de Hotline and it is free and available if you are ever feeling like self harm is the only way out:
800 273 8255
The electron dot diagram for a neutral atom of chlorine (atomic number 17) is shown below.
Which of the following symbols represents a chlorine ion with a stable arrangement of eight valence electrons?
A. 35Cl1-
B. 35Cl2-
C. 35Cl1+
D. 35Cl
Answer:
A. 35Cl1-
Explanation:
Chlorine needs 1 more electron to have full octet thus will take 1 electron and possess a -1 charge.
The pressure exerted by 0.002 moles of a gas in a 500 mL container at 25oC is:
Answer:
0.1715 atm
Explanation:
We use the Ideal gas equation to calculate this
Mathematically;
PV = nRT
rearranging, we have
P = nRT/V
from the question, we have
n = 0.002 moles
R = 0.082
T = 250 = 250 + 273 = 523 K
V = 500 ml = 500/1000 = 0.5 L
Plugging the values we have;
P = (0.002 * 0.082 * 523)/0.5
P = 0.1715 atm
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.
Which if the following matters occupies more space, assuming similar number of molecules? A.(Solid) B.(Liquid) C.(Gas) D. (Solid and gas)
Connie was making sodium chloride by adding an acid to an alkali. She followed the progress of the reaction with a pH sensor .What else could she have used to detect when the reaction was complete?
What Connie could have used to detect when the chemical reaction was complete is an: acid-base indicator.
A chemical reaction is a chemical process that involves the continuous rearrangement (transformation) of either the ionic, atomic or molecular structure of a chemical element through the breakdown and formation of chemical bonds, in order to produce a chemical compound.
When a strong acid such as Hydrogen chloride (HCl) react with a strong alkali such as Sodium hydroxide (NaOH), it gives rise to the formation of Sodium chloride (NaCl) and Water ([tex]H_2O[/tex]);
[tex]HCl + NaOH[/tex] ----> [tex]NaCl + H_2O[/tex]
The progress of the above chemical reaction can be followed by using a pH sensor and the final pH of a strong acid and strong base is seven (7), meaning it is neutral.
However, Connie could make use of an acid-base indicator to detect when the chemical reaction is complete.
An acid-base indicator can be defined as a chemical substance that changes color with respect to the pH (hydrogen ion concentration) of a solution or chemical reaction. Some examples of an acid-base indicator are:
Litmus paper.Methyl red.Red cabbage juice.Bromothymol blue.Methyl orange.Phenolphthalein.In conclusion, an acid-base indicator is typically used for detecting when a chemical reaction between an acid and an alkali is complete.
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Answer:When a strong acid such as Hydrogen chloride (HCl) react with a strong alkali such as Sodium hydroxide (NaOH), it gives rise to the formation of Sodium chloride (NaCl) and Water ();
---->
Explanation:
Consider the intermediate equations: 3 equations.
C(s) + O2(g) --> CO2(g) Delta H1 = -393.5 kJ
2CO(g) + O2(g) --> 2CO2(g) Delta H2 = -566.0 kJ
2H2O(g) --> 2H2(g) + O2(g) Delta H3 = 483.6 kJ
With the overall reaction:
C(s) + H2O(g) --> CO(g) + H2(g) Delta Hrxn = ?
QUESTION 1:
What must be done to calculate the enthalpy of reaction?
The first must be halved.
The first must be reversed.
The second must be halved.
The second must be reversed.
The third must be halved.
The third must be reversed.
QUESTION 2:
What is the overall enthalpy of reaction?
Delta Hrxn = ____ kJ
Answer:
C. The second equation must be halved
D. The second equation must be reversed
E. The third equation must be halved.
Delta Hrxn= 131.3 kJ
Explanation:
The correct answer is -582 KJ.
What is the enthalpy of reaction?
Enthalpy is the heat content of a system.The enthalpy change of a reaction is roughly equivalent to the amount of energy lost or gained during the reaction.A reaction is favored if the enthalpy of the system decreases over the reaction.What is the overall enthalpy of the reaction?
Equal to the sum of the standard enthalpies of the intermediate reaction steps is called overall enthalpyLearn more about enthalpy below,
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In the Lewis dot structure for H2CCH2, how many bonds are between the carbon atoms?
3
4
1
2
Answer:
2
Explanation:
The compound H2CCH2 has the condensed formula C2H4. The name of the compound is ethene. The compound is unsaturated, that is, it contains multiple bonds. The compound has a formula which fits into the general molecular formulae of alkenes (olefins) which his CnH2n.
Olefins have a double bonds between the carbon atoms. That is , the two carbon atoms in Olefins are connected via a double covalent bond. This now implies that the two carbon atoms in ethene (C2H4) are connected by two covalent bonds in the lewis structure of the molecule as is common for Olefins.
In the Lewis dot structure for [tex]\rm H_2CCH_2[/tex], there is one covalent bond present between the carbon atoms. The correct answer is option c.
A dot structure is a method of depicting an atom's valence electrons by placing dots around the atomic symbol. One valence electron is represented by each dot.
In the Lewis dot structure of [tex]\rm H_2CCH_2[/tex], there is one bond between the carbon atoms. This is because each carbon atom has two electrons in its valence shell, and each hydrogen atom has one electron in its valence shell.
The two carbon atoms share two electrons to form one covalent bond, and each carbon atom also shares one electron with a hydrogen atom to form two additional covalent bonds.
Therefore, the correct answer is option c. There is one bond (covalent bond) between the carbon atoms in the Lewis dot structure for [tex]\rm H_2CCH_2[/tex].
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please answer in details. what class of carbon is coal
What is solid carbon dioxide oxide
Answer:
dry ice
Explanation:
hope this helps
:)
Answer:
Dry Ice is the common name for solid carbon dioxide (CO2). It gets this name because it does not melt into a liquid when heated; instead, it changes directly into a gas (a process known as sublimation).
Explanation:
The part of the atom involved in chemical bonding is the what
Which of the following statements are true? Significant figures in a measurement are all measured digits, and one estimated digit None of the above Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements
Answer: Significant figures in a measurement are all measured digits, and one estimated digit
Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.
Explanation:
Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy or precision is known as significant digits.
The significant figures of a measured quantity are defined as all the digits known with certainty and the first uncertain or estimated digit.
Rules for significant figures:
1. Digits from 1 to 9 are always significant and have infinite number of significant figures.
2. All non-zero numbers are always significant.
3. All zero’s between integers are always significant.
4. All zero’s preceding the first integers are never significant.
5. All zero’s after the decimal point are always significant.
The true statements are
Significant figures in measurement are all measured digits, and one estimated digit
Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.
The following information should be considered:
The figures in a number that express the value or the magnitude of a quantity is known as significant digits.The significant figures of a measured quantity refers to all the digits known with certainty.Learn more: https://brainly.com/question/1979431?referrer=searchResults
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
Which equation represents fermentation? 1. C2H4 + H2O → CH3CH2OH 2. C2H4 + HCl → CH3CH2Cl 3. C6H12O6 → 2CH3CH2OH + 2CO2 4. 2CH3CHO → C3H5CHO + H2O
Answer:
3. C6H12O6 → 2CH3CH2OH + 2CO2
Explanation:
In fermentation a catabolic process occurs, where an organic substance (C6H12O6) is transformed into a simpler one (CH3CH2OH), through incomplete oxidation, which does not require oxygen. Sugars are transformed into ethyl alcohol and carbon dioxide.
The equation C₆H₁₂O₆ → 2CH₃CH₂OH + 2CO₂ represents fermentation
What is Fermentation ?Fermentation is an enzyme catalyzed, metabolic process whereby organisms convert starch or sugar to alcohol or an acid anaerobically releasing energy.
In this process a large molecule is broken down to a smaller molecule.
Among the Equations given Equation 3
C₆H₁₂O₆ → 2CH₃CH₂OH + 2CO₂
represents fermentation due to two reasons
It is the process of breaking down of SugarIt is breaking down of a large molecule into smaller molecules.To know more about Fermentation
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Un hidrocarburo tiene como composición en masa: C= 85.8% ; H= 14.2% . Como dato nos brindan que una molécula de este compuesto pesa: LaTeX: 2.1x10^{-22}g2.1 x 10 − 22 g. Hallar la fórmula molecular. Datos: P.A (uma): C=12, H=1
Answer:
[tex]C_{9.042}H_{17.958}[/tex]
Explanation:
(This exercise has been written in Spanish and for that reason explanation will be held in such language)
Por la definición del Número de Avogadro, un mol del compuesto contiene [tex]6.022 \times 10^{23}[/tex] moléculas. La masa de un mol se determina mediante regla de tres simple:
[tex]x = \frac{6.022\times 10^{23}\,molecules}{1\,molecule} \times (2.1\times 10^{-22}\,g)[/tex]
[tex]x = 126.462\,g[/tex]
Las participaciones másicas del carbono y el hidrógeno son, respectivamente:
[tex]m_{C} = 0.858\cdot (126.462\,g)[/tex]
[tex]m_{C} = 108.504\,g[/tex]
[tex]m_{H} = 126.462\,g - 108.504\,g[/tex]
[tex]m_{H} = 17.958\,g[/tex]
Ahora, el número de moles de cada elemento es calculado a continuación:
[tex]n_{C} = \frac{108.504\,g}{12\,\frac{g}{mol} }[/tex]
[tex]n_{C} = 9.042\,mol[/tex]
[tex]n_{H} = \frac{17.958\,g}{1\,\frac{g}{mol} }[/tex]
[tex]n_{H} = 17.958\,mol[/tex]
La fórmula molecular del hidrocarburo es:
[tex]C_{9.042}H_{17.958}[/tex]
what is the mass of 3.01x1023 atoms of iron(atomic mass of fe=56)
Answer:
mass=279grams
Explanation:
GIVEN DATA
number of atoms=3.01×10^23
avogadro's number=6.022×10^22
molar mass of iron=56g/moles
TO FIND
mass in gram of iron=?
SOLUTION
by using the formula
mass in gram=(number of atoms÷avogdro's number)×molar mass
mass=(3.01×10^23÷6.022×10^23)×56
mass=0.499×56
mass=27.9grams=28 grams
4. Which of these terms describes the process of acid rain wearing away limestone?
Acryptic erosion
B.chemical weathering
C.cryptobiotic weathering
D.chemical erosion
Answer:
B. Chemical weathering
Explanation:
Erosion is the process whereby the soil and rocks are washed away by wind, water, ice or gravity.
Weathering is the process of weakening and breaking down of rocks and minerals either by non-living (abiotic) or living (biotic) factors or by both, such as temperature changes, plants and animals, acids, salts and water, etc.
From the above definitions, it can be seen that acid wearing away limestone is a rock weathering process by a non-living agent, an acid.
Option A is wrong because the process is weathering
Option B is correct because an acid is a chemical and the process involved is weathering
Option C is wrong because an acid is non-living
Option D is wrong because the process involved is weathering
What would the molecular formula be if lithium and sulfur reacted to form a neutral compound?
Answer:
Li2SExplanation:
Since Lithium gives away one electron, I believe it goes to Sulfur.
Hope this helps! :)
Answer:
Li*2S
Explanation:
ed tell chem
Which material is most likely to be a base?
salt water
vinegar
coffee
orange juice
Answer:
Cooffee
Explanation:
the answer is coffee because coffee might be bitter
Answer:Coffee
Explanation:Water is neutral, while the other answers are mostly organic acids but salt water is neither acidic nor basic
Why would we want to correct for water vapor?
Answer:
The vapor pressure due to water in a sample can be corrected for in order to get the true value for the pressure of the gas.
Explanation:
Where do you find the molar mass of an element
Answer:
Mass of a given chemical element or compound divided by the amount of substance.
(g/mol)
Can something be an acid and a base? Why and why not
1. Look at yourself in the front of the spoon (the side where the food sits). What do you see?
The you see the image
Answer:
If you look at yourself in the front of the spoon, you see that the mirror forms an inverted real image.
Explanation:
The word 'concave' means to bend inwards.
A curved mirror is a mirror that has a curved reflecting surface.
The front side of the spoon is just like a concave mirror. If you look at yourself in the front of the spoon, you see that the mirror forms an inverted real image.
Concave mirrors produce real inverted image of an object only if it is placed further away from the mirror than the focal point.
Answer:
It shows me upside down like a ghost. OoooOooh
Explanation:
Boo
