Unit 4.2 quiz chemistry

Answer:

Gill Slits

Explanation:

For the one who asked what hind limbs are they are back legs :)

Answer:

There are 8 valence electrons

Explanation:

Answer:  60.7 g of [tex]PH_3[/tex] will be formed.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given volume}}{\text{Molar volume}}[/tex]    

[tex]\text{Moles of} H_2=\frac{60L}{22.4L}=2.68moles[/tex]

The balanced chemical reaction is

[tex]P_4(s)+6H_2(g)\rightarrow 4PH_3(g)[/tex]

[tex]H_2[/tex] is the limiting reagent as it limits the formation of product and [tex]P_4[/tex] is the excess reagent.

According to stoichiometry :

6 moles of [tex]H_2[/tex] produce = 4 moles of [tex]PH_3[/tex]

Thus 2.68 moles of [tex]H_2[/tex] will produce=[tex]\frac{4}{6}\times 2.68=1.79moles[/tex]  of [tex]PH_3[/tex]

Mass of [tex]PH_3=moles\times {\text {Molar mass}}=1.79moles\times 33.9g/mol=60.7g[/tex]

Thus 60.7 g of [tex]PH_3[/tex] will be formed by reactiong 60 L of hydrogen gas with an excess of [tex]P_4[/tex]

Answer:

hello the options related to your question is missing attached below is the complete question with the options

answer:

Any visible bands were found in the small area above the wells instead in the expected large bottom area of the gel, because Amanda should have placed the wells into the black (-) end of the chamber for DNA to move towards the opposite red (+) end of the gel.   (  2 )

Explanation:

Why Amanda did not see any bands in the region that she was expecting is because during electrophoresis ( which allows the distinguishing of various lengths of DNA fragments on a gel )  the DNA been negative will migrate to the positively charged  electrodes and  The shorter brands will move faster through the gel, providing DNA fragments arrangements on the gel according to size.

Answer: sorta

Explanation:

In fact, they do not flow at all: they simply vibrate back and forth. Because the atoms in a solid are so tightly packed, solid matter holds its shape and cannot be easily compressed

Answer:

The wavelength for the transition from n = 4 to n = 2 is 486nm and the name  name given to the spectroscopic series belongs to The Balmer series.

Explanation

lets calculate -

Rydberg equation-   [tex]\frac{1}{\pi } =R(\frac{1}{n_1^2} -\frac{1}{n_2^2})[/tex]

where ,[tex]\pi[/tex] is wavelength , R is Rydberg constant ( [tex]1.097\times10^7[/tex]), [tex]n_1[/tex] and [tex]n_2[/tex]are the quantum numbers of the energy levels. (where [tex]n_1=2 , n_2=4[/tex])

Now putting the given values in the equation,

                [tex]\frac{1}{\pi }=1.097\times10^7\times(\frac{1}{2^2} -\frac{1}{4^2} )[/tex][tex]=2056875m^-^1[/tex]

    Wavelength [tex]\pi =\frac{1}{2056875}[/tex]

             =[tex]4.86\times10^-^7[/tex] = 486nm

   Therefore , the wavelength is 486nm and it belongs to The Balmer series.

Answer: The formula of the hydrate is [tex]MnSO_4.2H_2O[/tex]

Explanation:

Decomposition of hydrated manganese sulphate is given by:

[tex]MnSO_4.xH_2O\rightarrow MnSO_4+xH_2O[/tex]

Molar mass of [tex]MnSO_4[/tex] = 151.0 g/mol

According to stoichiometry:

(151.0+18x) g of [tex]MnSO_4.xH_2O[/tex] decomposes to give 151.0 g of [tex]MnSO_4[/tex]

Thus 45.91 g of [tex]MnSO_4.xH_2O[/tex] decomposes to give= [tex]\frac{ 151.0}{151.0+18x}\times 45.91g[/tex]  of [tex]MnSO_4[/tex]

Also we are given : 37.07 g of  [tex]MnSO_4[/tex] is produced

Thus we can equate the two equations:

[tex]\frac{ 151.0}{151.0+18x}\times 45.91=37.07[/tex]

[tex]x=2[/tex]  

Thus the formula of the hydrate is [tex]MnSO_4.2H_2O[/tex]

Answer:

1 mol Li₂O₂/mol CO₂ or 1 mol CO₂/mol Li₂O₂

2 mol Li₂CO₃/mol O₂ or 1 mol O₂/2 mol Li₂CO₃

1 mol Li₂O₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol Li₂O₂

2 mol Li₂O₂/mol O₂ or 1 mol O₂/2 mol Li₂O₂

1 mol CO₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol CO₂

2 mol CO₂/mol O₂ or 1 mol O₂/2 mol CO₂

Explanation:

The balanced chemical equation is:

2 Li₂O₂ + 2 CO₂ → 2 Li₂CO₃ + O₂

The mole-to-mole relationships are provided by the chemical stoichiometric coefficients (2 for Li₂O₂, 2 for CO₂, 2 for Li₂CO₃ and 1 for O₂).

We have to relate the moles of 1 compound to the moles of another compound in the equation. So, we can start writing the relationships between reactants (Li₂O₂ and CO₂)

2 moles of Li₂O₂ react with 2 moles of CO₂ → 2 mol Li₂O₂/2 mol CO₂= 1 mol Li₂O₂/mol CO₂ or 1 mol CO₂/mol Li₂O₂

Now, the relationships between products (Li₂CO₃ and O₂):

2 moles of Li₂CO₃ are produced when 1 mol of O₂ produced → 2 mol Li₂CO₃/1 mol O₂= 2 mol Li₂CO₃/mol O₂ or 1 mol O₂/2 mol Li₂CO₃

Finally, between reactants and products:

2 moles of Li₂O₂ produce 2 moles of Li₂CO₃ → 2 mol Li₂O₂/2 mol Li₂CO₃= 1 mol Li₂O₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol Li₂O₂

2 moles of Li₂O₂ produce 1 mol of O₂ → 2 mol Li₂O₂/1 mol O₂= 2 mol Li₂O₂/mol O₂ or 1 mol O₂/2 mol Li₂O₂

2 moles of CO₂ produce 2 moles of Li₂CO₃ → 2 mol CO₂/2 mol Li₂CO₃= 1 mol CO₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol CO₂

2 moles of CO₂ produce 1 mol of O₂ → 2 mol CO₂/1 mol O₂= 2 mol CO₂/mol O₂ or 1 mol O₂/2 mol CO₂

Answer:

Heat is the process of something getting hot(temperatures going up). Cold is when something gets cold(temperature decreases).

Explanation:

The number of moles of silver atoms in the piece of jewelry is 0.08784 moles

Here is the complete question:

Suppose a piece of jewelry contains 5.29 × 10²² atoms of silver  . How many moles of silver atoms are in the piece of jewelry?

From the question,

A piece of jewelry contains 5.29 × 10²² atoms of silver.

To determine number of moles of silver atoms in the piece of jewelry,

We will use the formula

[tex]Number \ of \ moles = \frac{Number \ of \ atoms }{Avogadro's \ number}[/tex]

From the question

Number of atoms of silver = 5.29 × 10²² atoms

and

Avogadro's number = 6.022 × 10²³ atoms/mole

∴ [tex]Number \ of \ moles \ of \ silver \ atoms= \frac{5.29 \times 10^{22} }{ 6.022 \times 10^{23} }[/tex]

Number of moles of silver atoms = 0.08784 moles

Hence, the number of moles of silver atoms in the piece of jewelry is 0.08784 moles

Learn more here: https://brainly.com/question/10982975

Answer:

The reactionnis known as a decomposition reaction

The equation of the reaction is given below as:

H₂CO₃ -----> H₂O + CO₂

Explanation:

A reaction in which a single compound is split into two or more simpler substances is known as a decomposition reaction.

In the reaction in which when a soda can is opened and left to the environment, the fizz in the soda, carbonic acid, separates into water and carbon dioxide is an example of a decomposition reaction.

The equation of the reaction is given below:

H₂CO₃ -----> H₂O + CO₂

In the reaction above, a larger molecular weight compound, carbonic acid with the molecular, H₂CO₃ is splits into two simpler substances of smaller molecular weight, water, H₂O and carbon dioxide, CO₂.

This reaction rate is made faster by an increase in temperature and by a decrease in pressure of the soda.

Answer:

0.75mol/LNaOH

Explanation:

Data: Soln:

M= ? M= n/ V(l)

n= 3moles. M= 3mol/ 4L

V= 4L. M = 0.75 mol/LNaOH

Answer:

Explanation:

a) The forward reaction is exothermic, hence when temperature is increased the equilibrium shift towards the reactants side to get rid of the excess energy. This will mean that more reactants are produced decreasing yield

b) There are a fewer number of moles of gas on the right side compared to the left side (Just count the coefficients before each compound) so a higher pressure will mean that the equilibrium will shift towards the products side in order to decrease the pressure. This will mean that more products are formed increasing yield

c) When something is powdered it's surface area to volume ratio increases. A higher surface area means that the particles around it have more area to work on so the frequency of collisions will increase increasing the rate of reaction. This is why iron is powdered.

Answer:

ω-3 fatty acid and 19:4(Δ5,8,11,14)

Explanation:

From the image attached below:

We can see the structure of the delta nomenclature showing the numbers of carbons, numbers of double bonds, and the locations of the double bonds in the structure of the carboxylate salt.

Also, we can see the structure of the fatty acid where; the location of the first double bond from the methyl end is shown.

Hence, the designation which are accurate for these structures are:

ω-3 fatty acid and 19:4(Δ5,8,11,14)

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Answer: I think it is hydroxide ion but im not sure

Explanation:

I hope this helped!

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Answer:

Transform = The third one

Convergent  = the first one

Divergent = the second one

Explanation:

Answer:

294.87 gm  CaCl_2

Explanation:

The computation of the  mass of calcium chloride is shown below:

But before that following calculations need to be done

Number of moles of chlorine atom is

= 3.20 × 10^24 ÷ 6.022 × 10^23

= 5.314 moles

As we know that

1 mole CaCl_2 have the 2 moles of chlorine atoms

Now 5.341 mole chloride atoms would be

= 1 ÷ 2 × 5.314

= 2.657 moles

Now

Mass of CaCl_2 = Number of moles × molar mass of  CaCl_2

= 2.657 moles × 110.98 g/mol

= 294.87 gm  CaCl_2

Answer: Scientists use the term bioenergetics to describe the concept of energy flow (Figure 4.2) through living systems, such as cells. Cellular processes such as the building and breaking down of complex molecules occur through stepwise chemical reactions. Some of these chemical reactions are spontaneous and release energy, whereas others require energy to proceed. Just as living things must continually consume food to replenish their energy supplies, cells must continually produce more energy to replenish that used by the many energy-requiring chemical reactions that constantly take place. Together, all of the chemical reactions that take place inside cells, including those that consume or generate energy, are referred to as the cell’s metabolism.

Answer:

C. 1.2 x 10^-11

Explanation:

pOH = 14 - pH = 14 - 3.08 = 10.92

[OH-] = 10^-pOH = 10^-10.92 = 1.2 x 10^-11

Answer:

Borax is a natural mineral with a chemical formula Na2B4O7 • 10H2O. Borax also is known as sodium borate, sodium tetraborate, or disodium tetraborate. It is one of the most important boron compounds. The International Union of Pure and Applied Chemistry (IUPAC) name for borax is sodium tetraborate decahydrate.

Answer:

Explanation:

From the given information; we are to assign the correct naming for the molecular binary compounds.

01. CaCl2 → Calcium CHloride

02. HI (g) → Hydrogen mono iodide gas

03. HI (aq) →  Hydroiodic acid

04. BH3 → Borontrihydride

05. Cl2O6 → Dichlorine hexoxide

06. ClF → Chlorine monoflouride

07. P2Cl4 → Phosphorus tetrachloride

08. I2O5 → Diiodine pentaoxide

09. BrF5 → Bromine pentaflouride

10. HBr(aq) → Hydrobromic acid

11. IF7 → Iodine heptaflouride

12. NF3 → nitrogen triflouride

13. H2Se(aq) → hydroselenic acid

14. BrCl → Bromine monochloride

15. H2Se(g) → Hydrogen Selenide

16. SnO2 → Tindeoxide

17. HBr(g) →  Hydrogenbromide gas

18. AsF3 → Arsenic triflouride

19. N2O3 → Dinitrogentrioxide

20. IF4 → Iodine pentafluoride

01. hydroiodic acid  → HI (aq)

02. hydrogen monoiodide gas → HI (g)

03. diiodine tetraoxide → I2O4

04. bromine monofluoride → BrF

05. silicon tetrahydride  → SiH4

06.  tetraphosphorus hexaoxide → P4O6

07. disulfur monoxide → S2O

08. carbon monooxide → CO

09. hydrogen monochloride gas → Hcl

10. tetraphosphorus decaoxide → P4O10

11. dibromine monoxide → Br2O

12. dinitrogen tetrafluoride → N2F4

13. disilicon hexahydride → SiH6

14. tetraarsenic hexaoxide → As4O6

15. hydrochloric acid → HCl (aq)

16.  arsenic trihydride → AsH3

17. iodine heptafluoride → IF7

18. bromine dioxide → BrO2

19. disulfur decafluoride → S2F10

20. dichlorine heptaoxide → Cl2O7

Answer:

ik this isnt the answer but mathwa will solve all yours problems

Explanation:

Answer:

The nervous system has two main parts: The central nervous system is made up of the brain and spinal cord.

Explanation:

Answer:The answer is wetland or rainforest

Explanation:

It’s wetland or rainforest because its with the tropical zone and there will be no such thing as desert and mountain have those but the rainforest is with the tropic to so Goodluck with any of your test and hope this did not make sense xdd