A factory in your town uses cadmium as part of its manufacturing process. Due to recent economic conditions, cadmium is no longer available, and you must find a replacement. Suggest two elements that might be good replacements. Which of these would be your choice? Explain why.
Answer:
Zn
Explanation:
why blood is separated into different parts
Answer:
Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood. The resulting components are: a clear solution of blood plasma in the upper phase (which can be separated into its own fractions, see Blood plasma fractionation),
Answer: Centrifugal force is used to separate the components of blood – red blood cells, platelets and plasma – from each other. ... The red blood cells precipitate to the bottom of the bag, with the platelets above them, then the white blood cells and the plasma at the very top. Also because Each part of the blood has a different function. Separating the blood into parts lets patients get only the specific part or parts of the blood that they need. So a whole blood donation can be used for several patients.
Hope this helps have a awesome day/nigh❤️✨t
Explanation:
Whoever gets these 2 right gets brainliest! :)
the first one is A covalent bond.
the second one is Answer: B Decomposition
mathdrrggeszdrsz seer r-
Answer:
130!!
Explanation:
5. Given the formula of a substance:
H Hн H
IT
C-C-C=C
1
H
H
What is the total number of shared electrons in a
molecule of this substance?
A) 22
B) 11
C) 9
D) 6
A) 22
In a single bond one pair of electrons is shared, with one electron being contributed from each of the atoms. Double bonds share two pairs of electrons and triple bonds share three pairs of electrons. Bonds sharing more than one pair of electrons are called multiple covalent bonds.In the given molecule:
There are total 7 single bonds and 2 double bonds.
As we know, In a single bond one pair of electrons is shared and double bonds share two pairs of electrons.
Thus,
Total number of shared electrons in a molecule= 7*2+2*4=14+8=22
So, total number of shared electrons in a molecule is 22.
Therefore, option A) is correct.
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how many moles of nitrogen gas are produced in the reaction if we started with 6 moles of ammonium nitrate
Sulfur
how many electron shells in 4th shell?
Answer:
16 electrons in a sulfur atom. Looking at the picture, you can see there are two electrons in shell one, eight in shell two, and six in shell three.
Explanation:
hi, if your looking for extra points (50+) and brainiest here is ur chance, answer this question correctly plz
Its the warm air what helps them also of energy of the sun
Guys please help me i will mark brainly!
Answer:
D
Explanation:
Mercury(II) oxide decomposes to form mercury and oxygen, like this:
2Hg (l) + O2 (g) → 2HgO (s)
At a certain temperature, a chemist finds that a reaction vessel containing a mixture of mercury(II) oxide, mercury, and oxygen at equilibrium has the following composition:
compound amount
Hg 14.7g
O2 13.4g
HgO 17.8g
Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits. Clears your work. Undoes your last action. Provides information about entering answers.
Solution :
For the reaction given :
[tex]$\text{2Hg}_{(l)}+\text{O}_2_{(g)} \rightarrow \text{2HgO}_{(s)}$[/tex]
Thus we know that the equilibrium constant [tex]$K_c$[/tex] contains aqueous an dgas species only.
∴ [tex]$K_c=\frac{1}{[O_2]}$[/tex] ............(1)
Now at the equilibrium, an amount of the 13.4 g of oxygen was found in the vessel of 6.9 liters. For determining the concentration of the oxygen gas, we use :
[tex]$[O_2]= \frac{n_{O_2}}{V_{soln}}$[/tex] ................... (2)
Here, [tex]$n_{O_2}$[/tex] = no. of moles of oxygen gas (mol)
[tex]$V_{soln}$[/tex] = volume of solution (L)
Therefore the number of moles of the oxygen gas is calculated by directly using the molecular weight (31.9988 g/mol) as the conversion factor.
∴ [tex]$n_{O_2}= 13.4 \ g \times \frac{\text{1 mol}}{31.9988 \ g}$[/tex]
= 0.418 mol
Now substituting the known values in (2), we can find the equilibrium concentration of the oxygen gas :
[tex]$[O_2] =\frac{0.418 \ \text{mol}}{6.9 \ \text{L}}$[/tex]
= 0.0605 M
Therefore substituting the result in (1), the equilibrium constant for the reaction is :
[tex]$K_c=\frac{1}{0.0605}$[/tex]
= 16.52
what grade percentage is developing, proficient, exceeding, and emerging?
Answer:
Grade A is the best percentage that is developing, proficient, exceeding, and emerging
Calculate the percent composition (out of 100) by weight of potassium in potassium carbonate decahydrate.
Answer:
12.26%
Explanation:
MM K = 39.1 g/mol
MM K2CO3 . 10H2O = 2x39.1 + 12.01 + 3 x 15.99 + 10 x 18.02= 318.38 g/mol
% by weight = (MM K/MM K2CO3.10H2O ) x 100= (39.1/318.8) x 100=12.26 %
The percent composition by weight of potassium in potassium carbonate decahydrate is 13.98%
Let's represent the chemical formula of the compound as follows;
potassium carbonate decahydrate = CH₂0KO₁₃
The molecular mass of the compound can be calculated as follows:
Molecular mass of CH₂₀KO₁₃molecular mass = 12 + 20 + 39 + (16×13) = 279 g/molmass of potassium = 39 g
Therefore,
% mass of potassium = 39 / 279 × 100
% mass of potassium = 3900 / 279
% mass of potassium = 13.9784946237
% mass of potassium = 13.98 %
learn more on percentage composition here: https://brainly.com/question/3905173
Which of these statements best supports the idea that a cell is the basic unit of a living organism?
A.
The number of cells in an organism affects the size of that organism.
B.
A tissue is composed of cells with similar structure and function.
C.
Some organisms have only one cell.
D.
All organisms are made up of one or more cells.
Answer:
The answer is D.
Explanation:
I searched it up :)
Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. In the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) In the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) Calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions.
Answer:
Overall enthalpy change for the formation of one mole nitric acid from nitrogen, hydrogen and oxygen, ΔH = -376 KJ
Note: the question is incomplete. The complete question is given below:
Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. In the first step, nitrogen and hydrogen react to form ammonia: N₂(g) + 3H₂(g) → 2NH₃(g) ΔH = -92. kJ In the second step, ammonia and oxygen react to form nitric acid and water: NH3(g) + 2O2(g) → HNO3(g) + H2O(g) ΔH = -330. kJ Calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. Round your answer to the nearest kJ.
Explanation:
From Hess's law of constant heat summation, the total enthalpy change for a reaction is the sum of all changes without regard to the number of multiple stages or steps involved in a reaction.
Enthalpy is a state function as it does not depend on the path taken to attain its value. Therefore, the summation of the enthalpy changes involved in the individual steps in the reaction of the formation of nitric acid will be equal to the enthalpy change of the overall reaction step.
For the first reaction step:
N₂(g) + 3H₂(g) → 2NH₃(g) ΔH = -92. kJ
For the second reaction step:
NH₃(g) + 2O₂(g) → HNO3(g) + H2O(g) ΔH = -330. kJ
Overall reaction step:
[tex]\frac{1}{2}[/tex]N₂(g) + [tex]\frac{3}{2}[/tex]H₂(g) + 2O₂(g) → HNO₃ + H₂O ΔH = ?
The overall reaction for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen shows that the first reaction step should be divided by 2
[tex]\frac{1}{2}[/tex]N₂(g) + [tex]\frac{3}{2}[/tex]3H₂(g) → NH₃(g) ΔH = -46. kJ
Overall enthalpy change, ΔH = ΔH₁ + ΔH₂
Overall enthalpy change,ΔH = (-46 KJ) + (-330 KJ)
Overall enthalpy change,ΔH = -376 KJ
You have 0.531 L of gas in a container. What is the volume in mL?
Answer:
531 mL is the volume in mL
Answer:
Hi there!
I hope you are having an outstanding day.
I believe the answer to your question is 531!
Please adress me if I am incorrect. :)
Much love,
Pandora
Explanation:
hi, if your looking for extra points (50+) and br ainiest here is ur chance, answer this question correctly plz
3. The complex ion Co(H2O)6 2(aq) is pink when placed in solution. Addition of chloride ions creates an equilibrium with CoCl42- in the solution, which is blue in color. Write the balanced equation for the equilibrium. If CoCl42- solubility is endothermic, predict what will happen to the solution color if the solution is heated. What will happen if the solution is cooled
Answer:
See explanation
Explanation:
When the complex ion Co(H2O)6 2+(aq) is placed in solution and chloride ions are added, the following equilobrium is set up;
Co(H2O)62+(aq) + 4 Cl-(aq) <=> CoCl42-(aq) + 6 H2O(g)
Co(H2O)6 2+(aq) solution is pink in colour while CoCl42-(aq) solution is blue in colour.
Since the solubility of CoCl42-(aq) is endothermic, heating the solution will move the equilibrium position towards the right (more CoCl42-(aq) is formed and the solution is blue in colour).
When the solution is cooled, more Co(H2O)62+(aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in colour.
When the solution is cooled, more [tex]Co(H_2O)_6^{2+}[/tex] (aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in color.
Balanced equation for the equilibrium:When the complex ion [tex]Co(H_2O)_6^{2+}[/tex] (aq) is placed in solution and [tex]CoCl_4^{2-}[/tex] are added, the following equilibrium is set up;
[tex]Co(H_2O)_6^{2+}(aq) + 4 Cl^-(aq) < = > CoCl_4^{2-}(aq) + 6 H_2O(g)[/tex]
[tex]Co(H_2O)_6^{2+}[/tex] (aq) solution is pink in color while [tex]CoCl_4^{2-}[/tex](aq) solution is blue in color. Since the solubility of [tex]CoCl_4^{2-}[/tex](aq) is endothermic, heating the solution will move the equilibrium position towards the right (more [tex]CoCl_4^{2-}[/tex] (aq) is formed and the solution is blue in color). When the solution is cooled, more [tex]Co(H_2O)_6^{2+}[/tex] (aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in color.
Find more information about Equilibrium here:
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Which of the following do scientists use to form a hypothesis?

A.
A question and observations

B.
A conclusion and data

C.
A conclusion and a theory

D.
A question and opinions
Explanation:
The scientific method involves making observations and asking questions. Scientists form hypotheses based on these observations and then develop controlled experiments to collecting and analyze data. Using this data, they are able to draw conclusions and form questions for new scientific research.
:)ᴍᴀʀᴋ ᴀꜱ ʙʀᴀɪɴʟɪꜱᴛ
You want to decaffeinate your coffee by extracting the caffeine out with dichloromethane (they don't do it that way anymore, but they used to). It's too late to extract the caffeine from the coffee beans, because you've already brewed yourself a 200 mL cup of coffee. Your particular brand of coffee contains 100 mg of caffeine in that 200 mL cup. The partition coefficient of caffeine in dichloromethane/water is 9.0 (it is more soluble in the dichloromethane).
How much caffeine would still be in your 200 mL if you did:_____.
A. One extraction using 200 mL ofdichloromethane
B. Two extractions using 100 mL ofdichloromethan each.
Solution :
Partition coefficient Kd
[tex]$=\frac{\frac{\text{mass of caffeine in } CH_2Cl_2}{\text{volume of } CH_2Cl_2}}{\frac{\text{mass of caffeine in water}}{\text{volume of water}}}$[/tex]
= 9.0
A). 1 x 200 mL extraction :
Let m be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = 100 - m
[tex]$\frac{\frac{100-m}{200}}{\frac{m}{200}} = 9.0$[/tex]
[tex]$=\frac{100-m}{m} = 9.0$[/tex]
[tex]$= 10 m = 100$[/tex]
m = 10
Mass remaining in coffee = m = 10 mg
B). 2 x 100 mL extraction :
First extraction :
Let [tex]$m_1$[/tex] be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = [tex]$100-m_1$[/tex]
[tex]$\frac{\frac{100-m_1}{100}}{\frac{m_1}{200}} = 9.0$[/tex]
[tex]$=\frac{100-m_1}{m_1} = 4.5$[/tex]
[tex]$ 5.5 \ m_1 = 100$[/tex]
[tex]$m_1$[/tex] = 18.18
Mass remaining in coffee = [tex]$m_1$[/tex] = 18.18 mg
Second Extraction :
Let [tex]$m_2$[/tex] be the mass of caffeine in the water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = [tex]$18.18-m_2$[/tex]
[tex]$\frac{\frac{18.18-m_2}{100}}{\frac{m_2}{200}} = 9.0$[/tex]
[tex]$=\frac{18.18-m_2}{m_2} = 4.5$[/tex]
[tex]$ 5.5 \ m_2 = 18.18$[/tex]
[tex]$m_2$[/tex] = 3.3
Mass remaining in coffee = [tex]$m_2$[/tex] = 3.3 mg
help please guys i need it
Answer:
Amplitude
Explanation:
Hope I helped :)
A student plans a two-step synthesis of 1-ethyl-3-nitrobenzene from benzene. The first step is nitration of benzene to give nitrobenzene, and the second step is a Friedel-Crafts alkylation using CH3CH2Cl and AlCl3. The plan is flawed because: A : When the alkyl halide interacts with AlCl3, the resulting carbocation can rearrange before it has a chance to react with the aromatic ring. B : Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation. C : The nitro group will direct the incoming alkyl group para position, rather than to the meta position. D : A blocking group is required to achieve this synthesis.
Answer:
Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.
Explanation:
The benzene ring in itself does not easily undergo electrophilic substitution reaction. Some groups activate or deactivate the benzene ring towards electrophilic substitution reactions.
-NO2 ia a highly deactivating substituent therefore, Friedel-Crafts alkylation of nitrobenzene does not take place under any conditions.
This reaction scheme is therefore flawed because Nitrobenzene is too deactivated (by the nitro group) to undergo a Friedel-Crafts alkylation.
HELPPP PLZZ
During lunch each day, Alex and Hailey have been noticing the trashcans around the lunchroom are filling rather quickly with cans and bottles. They decide a recycling program would be beneficial for their school and the environment, so they brainstorm ways to get the program started. Before discussing their idea with the principal, they need to decide which of their plans would best solve the problem. Which of their ideas would best solve the problem with the least amount of inconvenience (disturbance) for everyone involved? A) Ask volunteers to separate recyclable materials from the trash. B) Remove all vending machines that sell plastic bottles or aluminum cans. C) Get a petition started to build a recycling center close to the school. D) Place plastic and metal recycling bins next to each lunchroom trash can
Answer:
c
Explanation:
i think it is C but idek but to me it sounds like the best answers but tell me if im wrong pls give me feedback
The ideas that would best solve the problem with the least amount of inconvenience is to place plastic and metal recycling bins next to each lunchroom trash can.
What is recycling?The term recycling has to do with the reuse of a material after it has passed through certain processes. The idea of recycling is highly beneficial to the environment.
Thus, the ideas that would best solve the problem with the least amount of inconvenience (disturbance) for everyone involved is to place plastic and metal recycling bins next to each lunchroom trash can.
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help plz and will give brainly
Suppose an EPA chemist tests a 250.mL sample of groundwater known to be contaminated with nickel(II) chloride, which would react with silver nitrate solution like this: NiCl2(aq) + 2AgNO3(aq) → 2AgCl(s) + NiNO32(aq) The chemist adds 15.0mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 5.8mg of silver chloride. Calculate the concentration of nickel(II) chloride contaminant in the original groundwater sample. Round your answer to 2 significant digits.
Answer:
0.0010 w/v %
Explanation:
Based on the reaction:
NiCl₂(aq) + 2AgNO₃(aq) → 2AgCl(s) + Ni(NO₃)₂(aq)
Finding the moles of AgCl produced we can find the moles of NiCl in the reaction medium and its mass:
Moles AgCl -Molar mass: 143.32g/mol-:
5.8mg = 5.8x10⁻³g * (1mol / 143.32g) = 4.047x10⁻⁵ moles AgCl
Moles NiCl₂:
4.047x10⁻⁵ moles AgCl * (1mol NiCl₂ / 2mol AgCl) = 2.023x10⁻⁵ moles NiCl₂
Mass NiCl₂ -Molar mass: 129.60g/mol-:
2.023x10⁻⁵ moles NiCl₂ * (129.60g / mol) = 2.62x10⁻³g of NiCl₂ are produced.
And the concentration in w/v% is:
2.62x10⁻³g NiCl₂ / 250mL * 100 =
0.0010 w/v %The concentration of a benzene solution prepared by mixing 12.0 g
C6H6 with 38.0 g CCl4 is __________ molal
Answer: The concentration of a benzene solution is 4.05 molal
Explanation:
Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.
[tex]Molality=\frac{n\times 1000}{W_s}[/tex]
where,
n = moles of solute
[tex]W_s[/tex] = weight of solvent in g
moles of [tex]C_6H_6[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{12.0g}{78g/mol}=0.154mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]molality=\frac{0.154\times 1000}{38.0g}=4.05[/tex]
Therefore, the concentration of a benzene solution is 4.05 molal
Hyenas eat larger mammals like antelope and wildebeest, but will also eat lizards, birds, snakes, and insects. What type of teeth would you expect a hyena to have?
Answer:
Large Sharp Teeth
Explanation:
i got a 100 on my test!
Large Sharp Teeth !
i got it right on my quiz
What is the atomic mass of element XX if 3.6 moles of the substance has a mass of 192 grams?
Answer:
53.3g/mol
Explanation
Moles=mass/molar mass
Molar mass= mass/moles
Molar mass= 192/3.6
= 53.3
Which example indicates that a chemical change has occurred? *
1 point
A. When two aqueous solutions are mixed, a precipitate is formed.
B. As ammonium nitrate dissolves in water causes the temperature to decrease.
C. Alcohol evaporates when left in an open container.
D. Water is added to blue copper(II) chloride solution. The resulting mixture if lighter blue in color.
Answer:
A. When two aqueous solutions are mixed, a precipitate is formed.
Explanation:
The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.
The other three answer choices are indicative of physical changes (temperature change, phase change, color change).
When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.
Hence, option A is correct answer.
What is Chemical change ?Chemical change are those changes in which substance changes chemical composition. These changes are permanent changes. In chemical change new substances formed and in chemical change substances can not get back into its original form. It is irreversible change.
What is Physical change ?Physical changes are those changes in which substance changes physical properties only. Properties like temperature, pressure, shape, color, size, state (solid, liquid and gas). These changes are temporary in nature. In physical change no new substances formed. It is reversible change.
Now, check all the options one by one:
Option (A): When two aqueous solutions are mixed, a precipitate is formed is a chemical change. Since precipitation indicate a chemical reaction (that is double displacement reaction).
Option (B): As ammonium nitrate dissolved in water causes the temperature to decrease is a physical change because heat energy is absorbed here and it is a endothermic reaction.
Option (C): Alcohol evaporates when left in an open container is a physical change because evaporation is a physical change as it changes the state from liquid state to gas state.
Option (D): Water is added to blue copper (II) chloride solution. The resulting mixture if lighter blue in color is a physical change as properties like change in color is physical change.
Thus, from above conclusion we can say that When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.
Hence, option A is correct answer.
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Which units can be used to measure length or distance? Check all that apply.
gram
meter
kilometer
liter
inch
Answer:
Meter, kilometer & inch - used to measure length or distance.
Pls help me over here
Answer:
1 and the element is hydrogen (there is an exception for the octet rule for the element hydrogen) hope this helps
Explanation: