Answer:
c. 1.0 mole C5H5N and 1.5 mole C5H5NHCl
Explanation:
We can determine pH of a buffer using H-H equation:
pH = pKa + log [A⁻] / [HA]
Where [A⁻] is concentration of conjugate base and [HA] concentration of weak acid. These concentrations can be computed as moles of each species.
We need to determine pKa of both NH₃ and C₅H₅N buffers, thus:
pKb = -log Kb
NH₃ pKb = -log 1.8x10⁻⁵ = 4.74
C₅H₅N pKb = -log 1.7x10⁻⁹ = 8.77
And pKa = 14 - pKb:
NH₃ pKa = 14 - 4.74 = 9.26
C₅H₅N pKb = 14 - 8.77 = 5.23
A buffer works only under pH's between pKa-1 and pKa + 1. As pKa NH₃ buffer is 9.23 is not possible to produce a buffer with pH 5.05 for this system.
Thus, we only will compute the buffers made with C₅H₅N:
c. 1.0 mole C5H5N (Weak base) and 1.5 mole C5H5NHCl (Conjugate acid)
pH = pKa + log [A⁻] / [HA]
pH = 5.23+ log [1.0 moles] / 1.5 moles]
pH = 5.05d. 1.5 mole C5H5N and 1.0 mole C5H5NHCl
pH = pKa + log [A⁻] / [HA]
pH = 5.23+ log [1.5 moles] / 1.0 moles]
pH = 5.41Right solution is:
c. 1.0 mole C5H5N and 1.5 mole C5H5NHClcompare the activity of sodium and iron with water and dilute acid
Answer:
Reactions of sodium with water and dilute acid
Sodium reacts explosively with dilute HCl(aq) to produce NaCl(aq) and H₂(g)
2Na (s) + 2HCl(aq) → 2NaCl(aq) + H₂(g)
Sodium reacts violently with cold water to produce NaOH(aq) and H₂(g)
2Na (s) + H₂O(l) → 2Na(OH)(aq) + H₂(g)
The produced hydrogen may become ignited and explode
Reactions of iron with water and dilute acid
Iron reacts very slowly with dilute acid to produce iron (II) chloride and hydrogen gas
Fe (s) + 2 HCl (aq) → FeCl₂ (aq) + H₂ (g)
Iron does not react with cold water. Iron reacts only with steam
Explanation:
Which are the physical properties of water
What is 16.30 to the 100th gram
Answer:
1.65485688 × 10121 grams
Explanation:
Aside from those discrete items, anything like rice or flour can be measured out to make up 100 grams. For example, 1/2 cup (125 ml or about 4 and 1/2 fl. oz) of dry rice weighs very close to 100 grams.
5) O etanol C2H6O, combustível produzido em grande escala no Brasil, pode ser obtido pela fermentação da sacarose C12H22O11 encontrada na cana-de-açúcar. Esse processo consiste na degradação por enzimas de micro-organismos da sacarose. Um técnico de laboratório preparou uma solução aquosa misturando 33 g de sacarose em 200 mL de água. Ao final, a solução ficou com um volume de 220 mL. Qual a concentração em g/l desta solução sabendo que a formula é C=Mg /VL a) 0,15 b) 0,165 c) 66 d) 15 e) 150
Answer:
a) 0.15
Explanation:
A concentração de sacarose é 0,15 g / l no etanol. O Brasil está produzindo etanol em grandes quantidades que é usado como combustível em veículos e indústrias. Este etanol é produzido a partir da cultura da cana-de-açúcar e o Brasil é o segundo maior produtor mundial com cerca de 34,45 bilhões de litros em 2019. Os Estados Unidos da América e o Brasil produzem cerca de 84% do etanol mundial.
The table describes how some substances were formed.
Substance
P.
Q
Description
Formed by boiling pure water
Formed by combining three hydrogen atoms to every nitrogen atom
Formed by adding 5 g of sugar to 1 L of water
Formed by compressing carbon under high pressure
R
S
Based on the given descriptions, which substance is most likely a mixture?
P
Q
R
S
Explanation:
Which is a pure substance?
1. soda
2. gasoline
3. salt water
4. carbon dioxide
carbon dioxide
Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of -7.2°C. Bromine can be classified as a
1. compound.
2. impure substance.
3. mixture.
4. pure substance.
pure substance.
Answer:
the answer is
Explanation:
Sugar and water make a homogeneous mixture (the same proportions of its components throughout any given sample).
If you are designing an experiment, how will you determine your independent or dependent variable?
Answer:
The independent variable effects the dependent variable.
Explanation:
The independent variable Is what you change whereas the dependent variable would change because of that.
for example, the indipendent variable could be how much you water a plant in ml each day, and the dependent variable would be how tall each plant grown]s with that water doseage per day.
PLZ HELP! TIMED TEST Which of the following groups of elements are likely to have elements in the three states of matter? (1 point)
Alkali metals
Actinides
Halogens
Lanthanides
Answer:
Halogens
Explanation:
Matter is defined as a substance which has mass and occupies volume. The three states of matter are solid, liquid and gas.
Elements which are present in group 17 are known as halogens.
Elements present in this group are fluorine, chlorine, bromine and iodine.
At room temperature, both fluorine and chlorine exists as a gas.
Bromine exists as a liquid and iodine exists as a solid.
Therefore, we can conclude that halogen groups are likely to have elements in three states of matter.
Which fact was most likely discovered between the time of Mendeleev’s table and the time of Moseley’s table that helped Moseley develop his version?
Answer:
The number of protons in an atom is different than the atom’s total mass.
Explanation:
Mendeleev knew only that, with some anomalies, the properties of elements varied periodically with their atomic masses.
Moseley's X-ray experiments enabled him to remove these anomalies and to show that the properties of elements varied with their atomic numbers.
Chadwick later discovered that the mass differences were caused by the presence of neutrons.
Which feature forms at Earth's surface from the cooling of lava?
O extrusion
fault
O intrusion
unconformity
Extrusion is the feature form at Earth's surface from the cooling of lava.
What are extrusive igneous rocks?They are the ones that originate from a sudden cooling of the incandescent magma when it comes to the surface, which means that there is no time for crystals to form, either partially or totally.
Characteristics of extrusive igneous rocksThese are rocks formed mainly by silicate minerals.Pyroclastics are the product of explosive volcanic eruptions and contain rock fragments of different origins, they can be of many shapes and sizes.Therefore, we can conclude that typical volcanic rocks are formed by the rapid cooling of lava and pyroclastic fragments.
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Answer:
A.
Explanation:
What is Mendeleev’s Periodic Law? How many elements were classified by Mendeleev?
Answer:
1.the law that the properties of the elements are periodic functions of their atomic numbers. Also called Mendeleev's law. (originally) the statement that the chemical and physical properties of the elements recur periodically when the elements are arranged in the order of their atomic weights.
Explanation:
2.Mendeleev’s Periodic Law states that the properties of elements are the periodic function of their relative atomic masses. Mendeleev arranged all 63 elements; which were discovered till his time; in the order of their increasing relative atomic masses in a tabular form. It is known as Mendeleev’s Periodic Table.
Please help, this assignment is to hard for me. :(
Answer:
603000 J
Explanation:
The following data were obtained from the question:
Energy required (Q) =...?
Mass (M) = 10000 g
Specific heat capacity (C) = 2.01 J/g°C
Overheating temperature (T2) = 121°C
Working temperature (T1) = 91°C
Change in temperature (ΔT) =.?
Change in temperature (ΔT) =T2 – T1
Change in temperature (ΔT) = 121 – 91
Change in temperature (ΔT) = 30°C
Finally, we shall determine the energe required to overheat the car as follow:
Q = MCΔT
Q = 10000 × 2.01 × 30
Q = 603000 J
Therefore, 603000 J of energy is required to overheat the car.
Why do.we need inactive ingredients?
Answer:
Inactive ingredients are components of a drug product that do not increase or affect the therapeutic action of the active ingredient, which is usually the active drug. Inactive ingredients are added during the manufacturing process of pharmaceutical products such as tablets, capsules, suppositories, and injections
CO2(g) + H2(g)
cog) + H2O(1)
What is being oxidized?
carbon
O carbon dioxide
oxygen
hydrogen
Answer:
Hydrogen
Explanation:
This may be wrong but I can't really tell because of how you have written the question
Answer: The answer is D. Hydrogen
Explanation:
I took the test
why does a desert cooler better on a hot dry day
Answer:On a hot dry day humidity will be less.when humidity decreases rate of evaporation increases
Answer:
The water that evaporates from a desert cooler takes in energy from the environment for filling up for the loss of energy during EVAPORATION making the environment cold.
Therefore, on a hot dry day, the Evaporation is more which means the environment will be colder.
Explanation:
I hope it is okay.
I learnt it last year, so I went back to my book and explained it better in my own way.
Thanks.
What is atom economy? A. All of these B. The system that determines how much 1 mole of a pure element costs. C. The measure of how much of the reactants end up as products in a chemical reaction. D. The system of exchanging electrons that occurs in atoms.
Answer:
C
Explanation:
It's the amount of products you get compared to all the reactants you use. It's kind of like economy in that it's profit, and the higher the atom economy the more products/profit you have.
Answer:
C.) The measure of how much of the reactants end up as products in a chemical reaction.
Explanation:
I got it right on founders edtell.
156. A solid metal sphere has a volume of 4.2 ft}. The mass
of the sphere is 155 lb. Find the density of the metal
sphere in grams per cubic centimeter.
Answer:
The answer is
0.59 g/cm³Explanation:
To find the density of the sphere we use the formula
[tex]Density \: = \frac{mass}{volume} [/tex]To find the density in g/cm³ first convert the mass into grams and the volume into cm³
For the mass we have
155 lb = 70306.82 g
For the volume
4.2 ft³ = 118930.76 cm³
Substitute the values into the above formula
That's
[tex]Density \: = \frac{70306.82 \: g}{118930.76 \: cm³} [/tex]We have the final answer as
Density = 0.59 g/cm³Hope this helps you
how scientific inferences can be made from scientific observations
Answer:
The scientific method is applied to inference through the steps taken to make both inductive and deductive inferences. Inductive inference begins with an observation, and then a pattern of such observation develops. One then makes a hypothesis based on the pattern and finally a theory based on the hypothesis
Hope it helps!
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Which element increases its oxidation number in this reaction? 3KOH + H3PO4 → K3PO4 + 3H2O
Answer:
The answer is "no changes in oxidation number "
Explanation:
Given equation:
[tex]3KOH + H_3PO_4 \longrightarrow K_3PO_4 + 3H_2O[/tex]
In the above-given equation, there are no changes in the oxidation number which can be defined as follows but first we defined the oxidation: In the chemical process, it requires the transfer of ions is oxidation. In particular, it means that products that supply electrodes are oxidized. In the given equation, when 3Potassium hydroxide reacts with phosphoric acid it will produce potassium phosphate and 3 moles of water.
1.) Given 30 grams of CO2, how many moles of CO2 would you have? How many individual molecules of CO2 is that?
2., Given 22 Grams of NaCl, How many moles of Nacl would you have? How many individual molecules of NaCl is that?
3.) Given 50 grams of ammonia NH3, How many moles of NH3 would you have? How many Molecules of NH3 is that?
Answer:
1a) .68 moles 1b)4.1E-23 molecules.
2a) .37 moles 2b) 2.27E-23 molecules
Explanation:
1a) CO2 is equal to 44 grams (C→12 grams,O→16 grams[·2]) .30g/44g is .68 moles.
1b) multiply 1A by advogadros number (6.022E-23)
2a) NaCl is 58 grams. 22/58 is .37 moles.
2b) multiply 2A by advogadros number.
you'd answer #3 the same way #1 and #2
The branch of science that deals with chemicals and bonds are called chemistry. The moles are units to calculate the quantity required to use the element.
The correct answer is mentioned below.
What are moles?The mole is the base unit of the amount of substance in the International System of Units (SI). It is defined as exactly 6.02214076×10^23 elementary entities which may be atoms, molecules, ions, or electrons.According to the question, the moles to the option is as follows:-
moles of 30 grams of CO2 is[tex]n =\frac{M}{M.M}\\ \\\frac{30}{44} \\\\=0.681\\\\[/tex]
The number of molecules is [tex]0.68 *6022*10^{23} =4.09496*10^{23[/tex].
2. moles of 22 grams of NaCl is
[tex]\frac{22}{44}\\ \\=0.5\\\\[/tex]
Molecules will be [tex]0.5*6.022*10^{23} = 3.011*10^{23}[/tex]
3. moles of 50-gram ammonia
[tex]\frac{50}{17} \\\\2.94\\[/tex]
The number of molecules is [tex]2.94*6.022*10^{23} = 1770*10^{23[/tex]
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3. How many meters above sea level is the base of your landform?
How many meters above sea level is the top of your platform?
Answer:
Base is 715 and top is 850.
Explanation:
715 meters above sea level is the base of my landform and 850 meters above sea level is the top of my platform. Base of landform from a sea level is a starting point of a city or region having same topography. This region has a specific height where it spreads we called it top of the platform. The starting point of my location is 715 meters above sea level spreads up to 850 meters of elevation.
C12H26 has a what boiling point than C10H22. higher or lower
Chromatography
separates a solution based
on differences in how its
components ________in
different phases of matter.
What is the term for the belief that one's own culture is superior to other
cultures?
O A. Cultural behavior
O B. Cultural competence
C. Cultural relativism
D. Cultural absolutism
Cultural absolutism is the term for the belief that one's own culture is superior to other cultures.
What is cultural absolutism?Cultural absolutism is one of the perspectives which is common in anthropology, but it can also be applied to non-scientific thoughts also. It assumes that there is a set of universal values which are objectively valid in every situation.
Today, pure cultural absolutism is seen as a harmful effect of ethnocentrism focusing on the belief that one's own culture is superior and the practice of holding other's cultures to the standard of our own. However, purely relativist anthropologists have also been critiqued for going too far, by denying any common humanity and being too lenient towards morally questionable practices. Contemporary approaches try to find a balance between the universal values, such as human dignity, and a more inclusive and relativistic side of culture.
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Ravi’s grandmother is suffering from diabetes. Her doctor advised her to take lassi with less fat content. Which of the following methods would be most appropriate for Ravi to prepare it? OPTIONS: a. Filtration b. Decantation c. Churning d. Sedimentation
Answer:
Explanation:
Hello friend
The answer is Churning.
Hope this helps
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Does Na2 gas posses metallic character? Explain your answer..
Explanation:
It contains Na2 molecules and the atoms in this molecule are held together by a purely covalent bond because the electronegativity of the two atoms is identical.Metallic bonding would not kick in until you make clusters of quite a few atoms. Such clusters would likely not be very stable because thermodynamically the larger the clump of material the more stable it gets. So they tend to coalesce until you have chunk of metal.Metallic bonding is in a sense a form of covalent bonding, but it is very collective (delocalized over a great many atoms) and electron deficient (there are more states than electrons to fill them up with, leading to conductive properties. This means that “a metallic bond” is a bit of an oxymoron like a forest with only one tree.Reply me in commentsYes, Na2 gas possesses a metallic character.
Does NA contain metallic bonds?In the stable state, metal sodium functions as an array of Na+ ions which can be surrounded by way of a sea of 3s electrons. However, it would be wrong to consider metal sodium as an ion when you consider that the ocean of electrons is shared by using all of the sodium cations, quenching the nice fee.
Sodium most effective has one valence electron. So, in metallic bonding, it is able to only donate one electron to be delocalized at some point of the structure. In steel bonding, the real bonding is the electrostatic force between the effective cations and the delocalized electrons.
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Find the density of a cube on Earth that weighs 1.5 kg and has a side-length of 10 cm.
Answer:
1500kg/m^3
Explanation:
Formula:
d=m/v
Given:
m=1.5kg
v=1000cm^3
(The side length of a cube is always equal to the others)
Required:
d=?
Solution:
d=m/v
d=1.5kg/1000cm^3
d=1.5kg/0.001m^3
d=1500kg/m^3
Hope this helps ;) ❤❤❤
How much energy has your body used, in joules, if your health
device indicates that 450 Calories were burned during your workout? How many
Calories are in a dinner containing 3.5 x 100 joules
Answer:
1,882.8 joules83.652 caloriesExplanation:
Given:
Amount in calories = 450 calories
Amount in joules = 3.5 × 100 joules
Find:
Change in joulesChange in caloriesComputation:
We know that,
1 calories = 4.184 joules
So,
Amount in calories = 450 calories
= 450 × 4.184
= 1,882.8 joules
Amount in joules = 3.5 × 100 joules
= [3.5 × 100] / 4.184
= 83.652 calories
Balance the reaction which forms ions. Choose "blank" if no coefficient other than 1 is needed. ZnBr2 what Zn + + what Br-
1 or 2 or black
Answer: [tex]ZnBr_2\rightarrow Zn^{2+}+2Br^-[/tex]
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here zinc is having an oxidation state of +2 called as [tex]Zn^{2+}[/tex] cation and bromide is an anion with oxidation state of -1. Thus 2 atoms of [tex]Br^-[/tex] will combine with one [tex]Zn^{2+}[/tex] and written in simplest whole number ratios to give neutral [tex]ZnBr_2[/tex]
[tex]ZnBr_2\rightarrow Zn^{2+}+2Br^-[/tex]
can someone send me something to get chemistry going ;);)
Answer:
Check out libretexts chemistry
Explanation:
It's basically an online free textbook for lots of subjects
highly recommended
Ok , whenever you wanna study chemistry , listen to music that you love. So each time you have to study chem , you will be excited bc u also wanna hear that music u love. Similarly , for every boring work you do , reward yourself for it. It helps , Im sure.
Thank you XD
Sarah is in her chemistry lab doing an experiment. When she goes to take the mass of the chemical she is working with, she discovers that the balance is gone! Sarah knows the density of her chemical is 10 g/mL, and the volume is 5 mL. What is the mass of her chemical?
Answer:
Mass of chemical = 50 gram
Explanation:
Given:
Volume of chemical = 5 ml
Density of chemical = 10 g/mL
Find:
Mass of chemical
Computation:
Mass of chemical = Density of chemical × Volume of chemical
Mass of chemical = 10 × 5
Mass of chemical = 50 gram
