How many molecules of methane gas (CH4) are in 32.1 grams of methane
Answer:
There are 1.8021⋅1024 molecules of CH4 in 48 grams of CH4 .
Explanation:
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100.00 mL of 0.15 M nitrous acid (HNO2) are titrated with a 0.15 M NaOH solution. (a) Calculate the pH for the initial solution. (b) Calculate the pH for the point at which 80.0 mL of the base has been added. (c) Calculate the pH for the equivalence point. (d) Calculate the pH for the point at which 105 mL of the base has been added.
Answer:
a. pH = 2.04
b. pH = 3.85
c. pH = 8.06
d. pH = 11.56
Explanation:
The nitrous acid is a weak acid (Ka = 5.6x10⁻⁴) that reacts with NaOH as follows:
HNO₂ + NaOH → NaNO₂(aq) + H₂O(l)
a. At the beginning there is just a solution of 0.12M HNO₂. As Ka is:
Ka = [H⁺] [NO₂⁻] / [HNO₂]
Where [H⁺] and [NO₂⁻] ions comes from the same equilibrium ([H⁺] = [NO₂⁻] = X):
5.6x10⁻⁴ = X² / 0.15M
8.4x10⁻⁵ = X²
X = [H⁺] = 9.165x10⁻³M
As pH = -log [H⁺]
pH = 2.04b. At this point we have HNO₂ and NaNO₂ (The weak acid and the conjugate base), a buffer. The pH of a buffer is obtained using H-H equation:
pH = pKa + log [NaNO₂] / [HNO₂]
Where pH is the pH of the buffer,
pKa is -log Ka = 3.25
And [NaNO₂] [HNO₂] could be taken as the moles of each compound.
The initial moles of HNO₂ are:
0.100L * (0.15mol / L) = 0.015moles
The moles of base added are:
0.0800L * (0.15mol / L) = 0.012moles
The moles of base added = Moles of NaNO₂ produced = 0.012moles.
And the moles of HNO₂ that remains are:
0.015moles - 0.012moles = 0.003moles
Replacing in H-H equation:
pH = 3.25 + log [0.012moles] / [0.003moles]
pH = 3.85c. At equivalence point all HNO2 reacts producing NaNO₂. The volume added of NaOH must be 100mL. That means the concentration of the NaNO₂ is:
0.15M / 2 = 0.075M
The NaNO₂ is in equilibrium with water as follows:
NaNO₂(aq) + H₂O(l) ⇄ HNO₂(aq) + OH⁻(aq) + Na⁺
The equilibrium constant, kb, is:
Kb = Kw/Ka = 1x10⁻¹⁴ / 5.6x10⁻⁴ = 1.79x10⁻¹¹ = [OH⁻] [HNO₂] / [NaNO₂]
Where [OH⁻] = [HNO₂] = x
[NaNO₂] = 0.075M
1.79x10⁻¹¹ = [X] [X] / [0.075M]
1.34x10⁻¹² = X²
X = 1.16x10⁻⁶M = [OH⁻]
pOH = -log [OH-] = 5.94
pH = 14-pOH
pH = 8.06d. At this point, 5mL of NaOH are added in excess, the moles are:
5mL = 5x10⁻³L * (0.15mol / L) =7.5x10⁻⁴moles NaOH
In 100mL + 105mL = 205mL = 0.205L. [NaOH] = 7.5x10⁻⁴moles NaOH / 0.205L =
3.66x10⁻³M = [OH⁻]
pOH = 2.44
pH = 14 - pOH
pH = 11.56Jena draws a Venn diagram to compare floods and storm surges. Which statement belongs in the region marked X? can be caused by hurricanes push water onto the shore pose the greatest threat to coastal residents pose the greatest threat to inland residents
Answer:A, can be caused by hurricanes
Explanation: got 100 on assignment
Answer:
a
Explanation:
what is a chemical bond?
how ate chemical bond different from each other?.
Worth 100 points plus ill mark brainliest
How many grams of sodium phosphate ( Na₃PO₄ )are required to make 125 milliliters of a 0.240 Molar solution?
4.92
6.48
8.44
12.5
Answer:
4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.
Explanation:
Molarity is a measure of concentration that indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
In this case:
Molarity= 0.240 Mnumber of moles= ?volume= 125 mL= 0.125 LReplacing in the definition of molarity:
[tex]0.240 M=\frac{number of moles}{0.125 L}[/tex]
Solving:
number of moles= 0.240 M*0.125 L
number of moles= 0.03 moles
Being the molar mass of sodium phosphate 164 g/mole, that is, the mass of one mole of the compound, you can calculate the mass of 0.03 moles using the following rule of three: if 1 mole of the compound has 164 grams, 0.03 moles contains how much mass?
[tex]mass=\frac{0.03 moles*164 grams}{1 mole}[/tex]
mass= 4.92 grams
4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.
How is heat transferred from one object to another? A. Heat moves from warmer objects to cooler objects. B. Heat moves from cooler objects to warmer objects. c. Heat moves between objects of the same temperature. D. Heat moves back and forth between two objects.
Answer: I believe the answer is A, heat moves from warmer objects to cooler objects. I know for sure it isn’t C or D though so A
The heat is transferred from one object to another as heat moves from warmer objects to cooler objects. The correct option is A.
What is the transfer of heat?There are three ways to transfer heat. They are conduction, convection, and radiation. Heat travels from one body to another body. If the temperature of two objects is different, then the heat travels from higher temperature to lower temperature.
Conduction is the transfer of energy when two objects ate in contact with each other. Convection is a transfer between object and environment. Radiation is when transferred by emission of electromagnetic radiation.
Thus, the correct option is A. Heat moves from warmer objects to cooler objects.
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In the process of photosynthesis, sunlight is converted into
Answer:
Chemical energy
Explanation:
By the use of electrons and protons from water
Answer:
chemical energy
Explanation:
Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of organic molecules (e.g., sugars). Photosynthesis powers almost all trophic chains and food webs on the Earth.
Calculate the number of total atoms in 195 grams of Ni(OH)2.
1.267 x 10 ^ 24 is the total number of atoms
What is the molarity of a solution created by adding 0.75 moles of lithium fluoride to 65 L of solution?
Answer:
Molarity=Moles of solute/volume of solution in Litres
Simply imputing your values
you have
0.75/65
0.0115M.
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Reaction Rates and Chemical Equilibrium: Mastery Test
Select the correct answer from each drop-down menu.
What effect does a decrease in temperature have on the overall rate of a chemical reaction?
The reaction rate will
A decrease in temperature decreases(blank)
The reaction rate will (blank)
Answer:
A decrease in temperature decreases the number of collisions between molecules . The reaction rate will decrease
Explanation:
A solution of HCl is made by dissolving .005 moles of HCl in 50 L of water. What is the pH of the solution? What is the pOH?
PH?
0.0001
4.00
11.00
2.3p
pOH?
2.00
4.00
10.00
12.00
Answer:
pH= 4; pOH= 10
Explanation:
HCl is a strong acid and therefore dissociates completely in a solution of water via HCl + H2O --> Cl- + H3O+.
Because it is a strong acid, [HCl] = [H3O+].
[HCl]= [H3O+]= (0.005 mol)/(50L)= 1.0 x 10^-4
pH= -log[H3O+]
pH= -log(1.0 x 10^-4)= 4
pH + pOH = 14
4 + pOH = 14
pOH= 10
Which type of substances do you separate into ions when writing the complete ionic equation?
a. Aqueous
b. Liquid
c. Gas
d. Solid
Answer:
a. Aqueous
Explanation:
Took the test
a shape with five sides is called a?
Answer:
A five-sided shape is called a pentagon.
Explanation:
Answered by NONE other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO!!!
Hope this helped!!!
Answer:
a pentagon
Explanation:
I remember that a pentagon has 5 sides
Which of the following molecules has a bent shape?
O A. CO2
O B. H20
O C. BeCl2
O D. NH3
How does water interact with hydrosphere in your own word plzzz
Answer:
[tex]\color{Blue}\huge\boxed{Answer} [/tex]
Water moves through the hydrosphere in a cycle. Water collects in clouds, then falls to Earth in the form of rain or snow. This water collects in rivers, lakes and oceans. Then it evaporates into the atmosphere to start the cycle all over again.
HELP PLZ
Carbon readily makes these bonds with other elements, primarily..?
Explanation:
Carbon has the ability to form long chains of carbon atoms as well as ringed compounds by continuously bonding to itself. This covalent bonds may be single, double, or triple. Carbon forms covalent bonds easily with other elements, especially hydrogen, oxygen, nitrogen, halogens, and a variety of nonmetals.
What is the chemical formula for iodine trichloride?
ОА. ЗІСІ
O B. ICI:
O c. 1, Cl₂
O D. 12C1
Answer:
I₂CL₆
Explanation:
Answer12C1
Explanation:
Check all that apply...helppppp
Answer:
dfgh
Explanation:
a solution of KCl in water has a concentration of 0.243 M. The solution has a volume of 0.580 L. How many grams of KCl are present in the solution?
Answer:
10.5 g
Explanation:
Step 1: Given data
Molar concentration of the solution (C): 0.243 MVolume of solution (V): 0.580 LStep 2: Calculate the moles of solute (n)
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
n = M × V
n = 0.243 mol/L × 0.580 L = 0.141 mol
Step 3: Calculate the mass corresponding to 0.141 moles of KCl
The molar mass of KCl is 74.55 g/mol.
0.141 mol × 74.55 g/mol = 10.5 g
How are compositional layers distinguished?
Explanation:
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layers
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition Depth
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition DepthCrust :The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle. 0-100km silicates
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition DepthCrust :The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle. 0-100km silicatesMantle :A layer of the Earth (or any planet large enough to support internal stratification) between the crust and the outer core. It is chemically distinct from the crust and the outer core. The mantle is not liquid. It is, however, ductile, or plastic, which means that on very long time scales and under pressure it can flow. The mantle is mainly composed of aluminum and silicates. 100-2900km iron and magnesium silicates
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition DepthCrust :The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle. 0-100km silicatesMantle :A layer of the Earth (or any planet large enough to support internal stratification) between the crust and the outer core. It is chemically distinct from the crust and the outer core. The mantle is not liquid. It is, however, ductile, or plastic, which means that on very long time scales and under pressure it can flow. The mantle is mainly composed of aluminum and silicates. 100-2900km iron and magnesium silicatesCore: The innermost layers of the Earth. The Earth has an outer core (liquid) and an inner core (solid). They are not chemically distinct from each other, but they are chemically distinct from the mantle. The core is mainly composed of nickel and iron. 2900-6370km meta
Make a
prediction about how a lack
of resources in an ecosystem
might impact the levels of
organization.
Answer:
Limiting factors of an ecosystem include disease, severe climate and weather changes, predator-prey relationships, commercial development, environmental pollution and more. An excess or depletion of any one of these limiting factors can degrade and even destroy a habitat.
Explanation:
The limiting factor of an ecosystem involve disease, weather change, climate change, environment pollution and more. An excess or depletion of any of these factor can destroy over habitat.
What is Ecosystem?An ecosystem is define as a community or a group of living organisms that live together and are dependent on each other.
There are two main types of ecosystem.
Terrestrial ecosystem-Terrestrial ecosystem are land based ecosystem and interaction of biotic and abiotic component in the specific area.
Example- forest, grassland desert etc.
Aquatic ecosystem-Aquatic ecosystem are ecosystem formed by surrounding water bodies. They are dependent on each other and their environment .
Example- lake, pond, river etc.
Thus ecosystem and their limiting factor have great impact on the level of organization.
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Quinine in a 1.664-g antimalarial tablet was dissolved in sufficient 0.10 M to give 500 mL of solution. A 15.00-mL aliquot was then diluted to 100.0 mL with the acid. The fluorescence intensity for the diluted sample at 347.5 nm provided a reading of 327 on an arbitrary scale. A standard 100 ppm quinine solution registered 180 when measured under conditions identical to those for the diluted sample. Calculate the mass of quinine in milligrams in the tablet.
Answer:
605.6mg of quinine
Explanation:
Based on Lambert-Beer's law, the intensity of an optical measurement is directely proportional to its concentration.
Unknown concentration gives a reading of 327
100 ppm gives 180 of intensity
The concentration of the diluted quinine tablet is:
327 * (100ppm / 180) = 181.67 ppm. The final dilution
The concentration of the first diluted solution is:
181.67 ppm * (100.0mL / 15mL) = 1211ppm
ppm could be defined as mass of solute (In this case of quinine) in mg per liter of solution. That is:
1211mg / L
As the tablet was diluted to 500mL = 0.5L, the mass of the quinine is:
0.5L * (1211mg / L) =
605.6mg of quinineDo these two points (equivalence point and titration endpoint) in a titration occur when the same volume of titrant has been added? please Explain.
Answer:
Show a picture
Explanation:
the sum of two number is 50,and their difference is 30.find the sum
Answer:
40 and 10
Explanation:
40 plus 10 is 50 40 minus 10 is 30
Answer:
40 and 10
Explanation:
PlEASE HELP! 40!
A radioactive form of sodium pertechnetate is used as a brain-scanning agent in medicine. Quantitative analysis of a sample with a mass of 0.8961 g found 0.1114 g of sodium and 0.4749 g of technetium. The remainder was oxygen. Determine the empirical formula.
Answer:
moles Na = 0.1114 g / 22.9898 g/mol=0.004846
moles Tc = 0.4562g /98.9063 g/mol=0.004612
mass O = 0.8961 - ( 0.1114 + 0.4562)=03285 g
moles O = 0.3285 g/ 15.999 g/mol=0.02053
divide by the smallest
0.02053/ 0.004612 =4.45 => O
0.004846/ 0.004612 = 1.0 => Tc
to get whole numbers multiply by 2
Na2Tc2O 9
Explanation:
Hope it right hope it helps
5.36 liters of nitrogen gas are at STP. What would be the new volume if we increased the moles from 3.5 moles to 6.0 moles?
Answer:
[tex]V_2=9.20L[/tex]
Explanation:
Hello there!
In this case, according to the given STP (standard pressure and temperature), it is possible for us to realize that the equation to use here is the Avogadro's law as a directly proportional relationship between moles and volume:
[tex]\frac{V_2}{n_2}= \frac{V_1}{n_1}[/tex]
In such a way, given the initial volume and both initial and final moles, we can easily compute the final volume as shown below:
[tex]V_2= \frac{V_1n_2}{n_1} \\\\V_2=\frac{5.36L*6.0mol}{3.5mol}\\\\V_2=9.20L[/tex]
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An unknown compound was found to be soluble in concentrated sulfuric acid; however, the 2,4-DNP, chromic acid, and potassium permanganate gave negative results. The only positive result detected was the ferrous hydroxide test. What is the most likely functional group present in such compound
Explanation:
2,4-DNP is negative: aldehyde and ketone absent
Chromic acid is negative: alcohol absent.
KMnO4 test negative: alkene absent
The only positive result is for Fe(OH)2.
Nitro group-containing compounds react with ferrous hydroxide to give amine and ferric hydroxide red ppt. Hence given compound contains the nitro group (-NO2).
Like in a cat's eye, the human pupil changes shape in response to changes in
the environment. What is the most likely function of this structure?
A. To allow humans to read
B. To allow humans to see clearly in different levels of light
C. To allow humans to see shades in color
D. To allow humans to see at varying distances
Answer:
B.
Our pupils contract and expand depending on the amount of light at any given time in order to avoid being blinded and to see better in the darkness.
Glucose can be consumed for energy in three ways one ends with glucose being converted into CO2,
another way it is converted into lactic acid/actate, and the third way ends with ethanol. We humans use
the first two ways. What do we call each of the three ways? When/why would we use each of the first
two ways, and why not the third way?
Answer:
In humans, there are two major processes used to convert glucose into energy. cellular respiration or aerobic respiration is one of these processes that take place in presence of oxygen that converts glucose into CO2.
The other process is lactic acid fermentation occurs in muscles in case of depletion of oxygen which converts glucose into lactic acid.
The third process is alcoholic fermentation does not take place in humans and occurs in yeast and some bacteria where they produce ethanol.
Humans cannot use alcoholic fermentation in their own body ferment as there is no genetic information in us to do so as it has encoded in yeast and bacteria.
Calculate how many grams of sodium acetate you expected to make from your starting amount of sodium bicarbonate (0.5g). This is your theoretical yield.
Equation: NaHCO3 + HC2H3O2 = NaC2H3O2 + H2O + CO2
