Answer:
Explanation:
pH = 4.55
[ H⁺ ] = 10⁻⁴°⁵⁵
= 2.82 x 10⁻⁵
Let the acid be HA and its molar concentration be a .
HA ⇄ H ⁺ + A ⁻
a - .094x10⁻³a .094x10⁻³a .094x10⁻³a
.094x10⁻³a = 2.82 x 10⁻⁵
a = 30 x 10⁻²
= .3
a - .094x10⁻³a = .3 - .094 x 10⁻³ x .3
= .29997 approx
Ka = 2.82 x 10⁻⁵ x 2.82 x 10⁻⁵ / .29997
= 7.95 x10⁻¹⁰ / .29997
= 26.5 x 10⁻¹⁰
= 27 x 10⁻¹⁰ ( rounding off to two digits )
Caffeine, a stimulant found in coffee and soda, has the following elemental composition: 49.48% carbon, 5.19% hydrogen, 16.48% oxygen and 28.85% nitrogen. The molar mass of caffeine is 119.19 g/mol. Determine the molecular formula of caffeine.
Answer:
Explanation:
C = 49.48
H = 5.19
O = 16.48
N = 28.85
ratio of moles
= 49.48 / 12 : 5.19 / 1 : 16.48 / 16 : 28.85 / 14
= 4.123 : 5.19 : 1.03 : 2.06
= 4 : 5 : 1 : 2
so the empirical formula = C₄ H₅O N₂
Let molecular formula = ( C₄ H₅ON₂ )ₙ ,
n ( 48 + 5 + 16 + 28 ) = 119.19
97 n = 194.19
n = 2 ( approx )
molecular formula = C₈ H₁₀O₂ N₄
Please help!!! I will give five stars and points for correct answer with an explanation.
What do the blue and red lines indicate?
A cold front is moving to the north and west before a warm front moves through.
A cold front is moving to the south and east before a warm front moves through.
A warm front is moving to the north and east before a cold front moves through.
A warm front is moving to the south and west before a cold front moves through.
Picture is attached.
Answer:
A cold front is moving to the north and west before a warm front moves through.
Explanation:
The blue line indicated a cold front and the red line indicates a warm front. Both lines are moving up (north) and to the left (west) on the globe. Key words are north and west, which indicates the direction of which the fronts are moving even if it is unclear of which front is before the other.
in the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely
Answer:
When there is no spark from the reaction
Explanation:
The reaction between the acid and the magnesium metal goes into completion when there is no more spark from the magnesium. Also, the magnesium would have totally disappeared into solution.
These physical observation marks the end of the reaction.
When Mg reacts with HCl hydrogen bubbles are released. The completion of the given reaction can be determined by the presence of bubbles above the HCl.
The reaction between HCl and Mg:[tex]\bold {Mg+ 2HCl\rightarrow MgCl_2 + H_2}[/tex]
In this reaction, Mg reacts with 2 moles of HCl to form 1 mole of Magnesium chloride and release hydrogen gas.
During reaction,
Magnesium slowly disappears as it reacts with HCl.The hydrogen gas is released during the reaction, bubbles can be observed.Therefore, the completion of the given reaction can be determined by the presence of bubbles above the HCl.
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What is chemical weathering
Explanation:
Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
find examples for each polysaccharides type.
Answer:
Glycogen: It is made up of a large chain of molecules. ...
Cellulose: The cell wall of the plants is made up of cellulose. ...
Starch: It is formed by the condensation of amylose and amylopectin. ...
Insulin: It is made up of a number of fructofuranose molecules linked together in chains.
Explanation:
Which is a chemical property of soda ash?
Explanation:
A chemical property of soda ash is, it is a alkaline compound
In which orbitals would the valence electrons for selenium (Se) be placed?
Answer:
Valence electrons of selenium will be placed in s and p-orbitals.
Explanation:
Hope this helps.
What type of change is sugar dissolving in water physical or chemical
Answer:
Physical
Explanation:
No new substance is formed.
The process can be reversed using evaporation to separate the sugar from the water
So the change is physical
Hope this helps :)
is the center of an atom is called the nucleus?
Answer:
The center of the atom contains the nucleus so yes
Explanation:
7.46 - A 0.0500-mol sample of a nutrient substance is burned in a bomb calorimeter containing 2.00 x 10g H20. If the formula weight of this nutrient substance is 114 g/mol, what is the fuel value (in nutritional Cal) if the temperature of the water increased 5.70C?
Answer:
[tex]200\frac{kcal}{g}[/tex]
Explanation:
Hello!
In this case, for this calorimetry problem, since the combustion 0.0500 mol of the nutrient increase the temperature of water by 5.70 °C, we can notice that the heat lost by the nutrient is gained by water in order to write:
[tex]Q_{nutrient}=-Q_{water}[/tex]
Which can be also written as:
[tex]Q_{nutrient}=-m_{water}C_{water}\Delta T_{water}\\\\Q_{nutrient}=-200 g*4.184\frac{J}{g\°C}*5.70\°C\\\\Q_{nutrient}=4769.8 J[/tex]
Thus, in terms of the grams of the nutrient:
[tex]m_{nutrient}=0.0500mol*\frac{114g}{1mol}=5.70g[/tex]
The fuel value in nutritional Cal (kcal/g) turns out:
[tex]Fuel \ Value=\frac{-4.7698kJ}{5.70g}*\frac{1kcal}{4.184kJ}=200\frac{kcal}{g}[/tex]
Best regards!
help please please please!
Answer:
I say the second one, im not rlly sure tho
Explanation:
How many liters of CH3OH gas are formed when 3.20 L of H2 gas are completely reacted at STP according to the following chemical reaction?
Remember 1 mol of an ideal gas has a volume of 22.4 L at STP
CO(g) + 2 H₂(g) → CH₃OH(g)
Answer:
1.6 L CH3OH
Explanation:
3.20 L H2 x (1 mol H2/22.4 L H2) x (1 mol CH3OH/2 mol H2) x (22.4 L CH3OH/1 mol CH3OH) = 1.60 LCH3OH
1.602 liters of CH₃OH gas are formed when 3.20 L of H₂ gas are completely reacted at STP according to the following chemical reaction:
CO(g) + 2 H₂(g) → CH₃OH(g)
Remember 1 mol of an ideal gas has a volume of 22.4 L at STP
To find the volume of CH₃OH gas formed when 3.20 L of H₂ gas is completely reacted, we need to use stoichiometry and the given balanced chemical equation.
The balanced equation is:
CO(g) + 2 H₂(g) → CH₃OH(g)
From the balanced equation, we can see that 1 mol of CO reacts with 2 moles of H₂ to produce 1 mole of CH₃OH.
Step 1: Convert the given volume of H₂ gas to moles at STP.
Using the information provided, 1 mol of any ideal gas at STP (Standard Temperature and Pressure) occupies 22.4 L.
Number of moles of H₂ gas = Volume of H2 gas at STP / Volume of 1 mol of H₂ gas at STP
Number of moles of H₂ gas = 3.20 L / 22.4 L/mol
Number of moles of H₂ gas = 0.14286 moles (rounded to 5 decimal places)
Step 2: Use stoichiometry to find the moles of CH₃OH formed.
From the balanced equation, we know that 1 mol of CO reacts with 2 moles of H₂ to produce 1 mole of CH₃OH.
Since the ratio of H₂ to CH₃OH is 2:1, the number of moles of CH₃OH formed will be half of the moles of H₂ used in the reaction.
Number of moles of CH₃OH = (1/2) * Number of moles of H₂
Number of moles of CH₃OH = (1/2) * 0.14286
Number of moles of CH₃OH = 0.07143 moles (rounded to 5 decimal places)
Step 3: Convert the moles of CH₃OH to volume at STP.
Using the information provided, 1 mol of any ideal gas at STP (Standard Temperature and Pressure) occupies 22.4 L.
Volume of CH₃OH gas at STP = Number of moles of CH₃OH * Volume of 1 mol of CH₃OH gas at STP
Volume of CH₃OH gas at STP = 0.07143 moles * 22.4 L/mol
Volume of CH₃OH gas at STP = 1.602 L (rounded to 3 decimal places)
Therefore, approximately 1.602 liters of CH₃OH gas are formed when 3.20 liters of H₂ gas are completely reacted at STP.
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Which of the two forces is greater the force on the firefly or the force on the bus explain your answer please I really need help please
It’s due today please
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
Write the balanced chemical equation for the following reaction. Phases are optional. Solid iron(I) oxide reacts with hydrogen gas to form solid iron and liquid water. 2Fe+3H,Ol Fe,O,+ 3H2 â 2Fe+ 3H2O(I)
Answer:
[tex]Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(l)[/tex]
Explanation:
Hello!
In this case, when writing chemical reactions from the given names we must make sure we know the proper formula for each reacted and produced species; thus, since solid iron (III) oxide is [tex]Fe_2O_3[/tex], hydrogen gas is [tex]H_2[/tex], solid iron is Fe and liquid water is just [tex]H_2O[/tex], we can write:
[tex]Fe_2O_3(s)+H_2(g)\rightarrow Fe(s)+H_2O(l)[/tex]
However, since different amount of atoms of iron, hydrogen and oxygen are present at each side of the equation, we balance it by adding the following coefficients to each molecule:
[tex]Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(l)[/tex]
And now it is balanced with two iron atoms, three oxygen atoms and six hydrogen atoms at both reactants and products.
Best regards!
In the US, nutritional energy is reported in Calories (Cal). One nutritional Calorie is equal to one kilocalorie (kcal). If a food package reports 250.0 Calories (Cal) per serving, how many calories (cal) are in each serving?
Answer:
2.500 × 10⁵ cal
Explanation:
1kcal= 1000 cal
From the analysis, the number of calories in each serving of a food with 250 Calories would be 250,000 calories.
According to the illustration:
1 Calories = 1 kilocalories
The food package reports 250 Calories
Hence, 250 Calories = 1 x 250 kilocalories
= 250 kilocalories
According to metrics, 1 kilocalories = 1,000 calories
Thus, 250 kilocalories = 250 x 1000 calories
= 250,000 calories
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In case of accidental contact with chemicals, how long should the eyes be flushed at the eyewash station
Answer:
See the answer below
Explanation:
The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends of the nature of the chemical.
If the chemical is known to be a non-irritant or mild-irritant one, a 5-minute washing time is recommended as the first aid. before seeking the help of a physician,
For moderate to severe irritant chemicals, an immediate 15-20 minutes washing period is recommended before seeking further medical help.
For corrosive and strong alkalis chemicals, 30 and 60 minutes washing are recommended respectively before seeking the attention of a physician.
However, if the nature of the chemical is unknown, a minimum of 20-minutes washing is generally recommended as first aid before seeking immediate medical help.
The duration of flushing the eyes at the eyewash station in case of accidental contact with chemicals depends on the nature of the chemical.
If the chemical is known to be a non-irritant or mild-irritant one, a 5-minute washing time is recommended as the first aid. before seeking the help of a physician,For moderate to severe irritant chemicals, an immediate 15-20 minutes of washing is recommended before seeking further medical help.For corrosive chemicals, 30 and 60 minutes of washing are recommended respectively before seeking the attention of a physician.If the nature of the chemical is not known, a minimum of 20-minutes of washing is generally recommended as first aid before seeking immediate medical help.
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Anyone know this ???
[tex]\huge\boxed{OptionB}[/tex]
_____________________________________VESSEL A:The superior vena cava (SVC) is the superior of the two venae cavae, It is located above inferior vena cava and it returns the deoxygenated blood from the systemic circulation to the right atrium of the heart.
----------------------------------------------------------------------VESSEL C:The aorta is the main artery that carries blood away from your heart to the rest of your body.
----------------------------------------------------------------------ATRIUM D:The Left Atrium is one of the two atriums, it receives the oxygenated blood from the lungs via Pulmonary vein.
----------------------------------------------------------------------VENTRICLE E:The Left Ventricle is one of the two ventricles, it receives the oxygenated blood by the Left atrium through the mitral valves. From the ventricle oxygenated blood is provided to the whole body.
----------------------------------------------------------------------VESSEL B:Pulmonary Artery is one of the two pulmonary vessels which connect the blood heart and lung. Pulmonary Artery takes the deoxygenated blood from the Right ventricle to the Lungs from the oxygenation.
_____________________________________Best Regards,'Borz'
2)
The amount of energy required to remove all the valence electrons from a cesium atom is
A)
944 kJ/mol
B)
376 kJ/mol
C)
520 kJ/mol
D)
238 kJ/mol
Answer:
c 520kj mol
Explanation:
times all the electrons
Which descriptions are true regarding different muscle types? Select four options.
Cardiac and skeletal muscles are striated.
Skeletal and smooth muscles are nonstriated.
Smooth and cardiac muscles are voluntary.
Heart and digestive muscles are involuntary muscles.
Smooth and skeletal muscles are involved in movement.
Cardiac muscles work to pump blood.
Answer:
1, 4, 5, 6
Explanation:
Answer:
1,4,5,6
Explanation:
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Answer:
Ill do it for free hmu on Insta (allmyhomiesbeautiful) or Snap (nzmbndzmb)
Which unit of measurement would best be used to measure the volume of a points a DROP of water? .
Answer:
milliliter
Explanation:
smallest form of measuring volume from all the available choices
What is the definition of an Isomer?
Answer:
Each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.
Explanation:
I AM GIVING A LOT OF POINTS SO PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Can someone please help me with this?
Rules:
Label the section of the roller coaster where the kinetic or potential energy is.
Answer:c
Explanation:
it’s gained kinetic from the gravitational potential energy at the top
Arrange in order of decreasing atomic radii: Kr, K, Ge, Ca
Answer:
K > Ca > Ge > Kr
Explanation:
The elements given are all in the 4th period on the periodic table.
Kr, k, Ge, Ca;
Arranging their order from left to right;
K, Ca, Ge, Kr
Atomic radius is taken as half the of the inter-nuclear distance (d) between two covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.
Across the periodic table atomic radii decreases progressively from left to right. This is due to progressive increase in the nuclear charge (number of protons in the nucleus) without an attendant increase in the number of electronic shells.
From the left to right; decreasing radii;
K > Ca > Ge > Kr
Decide which of the following statements are true and which are false, concerning the kinetic molecular theory.
1. The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas.
A. True
B. False
2. The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other.
A. TrueB. False
3. The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL.
A. TrueB. False
4. The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory.
A. TrueB. False
5. The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas.
A. TrueB. False
Answer:
1. A. True
2. A. True
3. B. False
4. A. True
5. B. False
Explanation:
1. The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas. A. True. The pressure of an ideal gas is higher than the one that would exert a real gas.
2. The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other. A. True. The intermolecular forces are negligible.
3. The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL. B. False. The volume of the gas particles is negligible.
4. The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory. A. True. We cannot apply ideal gas laws to real gases.
5. The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas. B. False. The average kinetic energy of a collection of gas particles is assumed to be directly proportional to the Kelvin temperature of the gas.
The given statement, "if the particles are in constant motion and there are collisions of the particles with the walls of the container, then they are the cause of the pressure exerted by the gas." is:
TrueThe given statement "The particles are assumed to exert no forces on each other; they are assumed neither to attract nor to repel each other" is:
True
The given statement, "The particles are so small compared with the distances between them that the volume of the individual particles can be assumed to be about 1 mL" is:
False
The given statement ,"The molecules in a real gas have finite volumes and do exert forces on each other, thus real gases do not conform to some of the assumptions of an ideal gas as stated by the kinetic molecular theory" is:
True
The given statement, "The average kinetic energy of a collection of gas particles is assumed to be inversely proportional to the Kelvin temperature of the gas" is:
FalseRead more here:
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The ingredients of a soup include
1,500 grams of water, 350 grams of vegetables, and 210 grams of meat. What is the total mass of the soup?
Answer:
sopas
Explanation:
lagyan mo ng condense
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the total mass of the soup is 2,060gram.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.
mass of soup= mass of water+ mass of vegetables + mass of meat
mass of water=1,500 grams
mass of vegetables= 350 grams
mass of meat=210 grams
substituting all the values in the above equation, we get
mass of soup= 1,500 grams+ 350 grams + 210 grams
= 2,060gram
Therefore, the total mass of the soup is 2,060gram.
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Calculate pCl for the titration of 100.0mL of 0.1000 MCI with 0.1000 M
AgNO3 for the addition of 0.00 and 20.00 mL AgNO3.
the titration is the most important part in determining whether
how to covert ethanol into 2-butanol.(show reaction)
Explanation:
Conversion -
Ethanol to 2-butanolCH₃–CH₂–OH → CH₃–CH₂– CH(OH)–CH₃
Explaination -
CH₃–CH₂–OH + HCl → CH₃–CH₂– Cl + H₂O
Now,
CH₃–CH₂– Cl + 2Na + Cl–CH₂–CH₃ → CH₃–CH₂–CH₂–CH₃ + 2NaCl (wurtz reaction)
Now,
CH₃–CH₂–CH₂–CH₃ + Cl₂ → CH₃–CH₂–CH₂–CH₂–Cl + HCl (Halogenation)
Now,
CH₃–CH₂–CH₂–CH₂–Cl + KOH (alc.) → CH₃–CH₂–CH=CH₂ + KCl + H₂O
Now,
CH₃–CH₂–CH=CH₂ + H₂O → CH₃–CH₂–CH(OH)–CH₃ (Hydration of alkene by MR addition rule)
In the nucleus of an atom, there are 17 protons and 18 neutrons. What is the atomic number? What is the atomic mass? How many electrons are there?
Answer:
atomic number =17
mass number = 17+18= 35
Is adding food coloring to frosting a chemical reaction?
Answer:
no
Explanation:
Answer:
Yes
Explanation:
Adding food coloring to batter or to your icing involves a chemical reaction of the two products bonding together. This bonding process starts when you add the color and mix it in, but it doesn't end straight away as the color needs some time to fully integrate and settle.