please helppp
which one??????????

Please Helpppwhich One??????????

Answers

Answer 1
The answer should be B
.
Hopes this helps :D

Related Questions

How many grams of Ag2CO3 will precipitate when excess Na2CO3 solution is added to 40.0 mL of 0.679 M AgNO3 solution

Answers

Answer:

The answer is "[tex]37.45364 \ g[/tex]"

Explanation:

Equation:

[tex]2AgNO_3 (aq) + Na_2CO_3 (aq) \longrightarrow Ag_2CO_3 (s) + 2NaNO_3 (aq)[/tex]

Calculating  the mol of  [tex]AgNO_3[/tex]:

[tex]\to V = 40.0 mL\\\\[/tex]

       [tex]= 40.0 \times 10^{-2} \ L \\\\[/tex]

[tex]\to n = Molarity \times Volume \\\\[/tex]

       [tex]= 0.679 \times 40.0 \times 10^{-2}\\\\= 27.16 \times 10^{-2} \ mol[/tex]

mol of [tex]Ag_2CO_3= \frac{1}{2} \times n\\\\[/tex]

                         [tex]= \frac{1}{2} \times 27.16 \times 10^{-2}\\\\= 13.58 \times 10^{-2}\\\\[/tex]

Calculating the molar mass of [tex]Ag_2CO_3[/tex],:

[tex]= 2\times MM(Ag) + 1 \times MM(C) + 3 \times MM(O)\\\\= 2 \times 107.9 + 1 \times 12.01 + 3 \times 16.0\\\\= 275.81 \ \frac{g}{mol}[/tex]

Calculating the mass of [tex]Ag_2CO_3[/tex],

[tex]m = mol \times molar \ mass[/tex]

   [tex]= 13.38 \times 10^{-2}\ mol \times 2.758 \times 10^2 \ \frac{g}{mol}\\\\= 37.45364 \ g[/tex]

An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.

Answers

Answer: The percent yield of the reaction is 77.0 %

Explanation:

[tex]2Pb+O_2\rightarrow 2PbO[/tex]

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]

[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]

According to stoichiometry:

2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]

2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]

Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]

percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]


The three lines in this Lewis dot structure represent the.
A)
three valence electrons of dinitrous oxide.
B)
six electrons in the triple bond of diatomic nitrogen.
C)
three electrons joining two nitrogen atoms in a diatomic molecule.
D)
three double bonds between the valence electrons of diatomic nitrogen.

Answers

Answer:

B) . six electrons in the triple bond of diatomic nitrogen

Explanation:

The three line in this Lewis dot structure represents the six electrons in the triple bond of diatomic nitrogen.

Nitrogen is made up of 7 electrons with 5 valence ones.

 A lewis structure is made up of the symbol of the element surrounded by dot to represent the valence electrons.

  In this nitrogen molecule, both species share  6 electrons. This makes each nitrogen atom isoelectronic with neon.

A commonly held idea about influenza is that it is a disease that occurs primarily in cold weather. Doctors report incidences of illness, such as influenza, to the Centers for Disease Control (CDC). The graph below shows data for three flu seasons. Note that this graph shows data from October, week 40, of one year to July, week 28, of the following year.

Which evidence supports this idea?
The graph line for 2008-09 has the highest peaks for flu.
All three graph lines show different patterns throughout the year.
The graph line for 2008-09 has a peak in week 44.
All three graph lines peak over the same few weeks of winter.

Answers

Answer:

D.All three graph lines peak over the same few weeks of winter.

Explanation:

took the test

A Barometer reads 29.1 inches of mercury.Calculate this pressure in mmHg.

What is the answer?​

Answers

This follows a simple conversion technique. Basically what the question is trying to say here is to convert 29.1 inHg to mmHg. 1 inHg is equal to 25.4 mmHg so 29.1 inHg would be equal to [tex]25.4 * 29.1[/tex] which when evaluated turns out to be: [tex]739.14[/tex]. :D

The pressure will be 739.14 mm Hg.

What is pressure?

The SI unit measuring pressure would be the pascal, which measures the force of each unit area of the surface.

Calculation of pressure

It is known that 1inHg = 25.4 mm Hg.

Hence, the pressure = 25.4 × 29.1 = 739.14 mm Hg

Therefore, the pressure will be 739.14 mm Hg.

To know more about pressure

https://brainly.com/question/15175692

#SPJ2

PLEASE HELP ME!!!!!!!!!!!!!!!!!!!
WRITE A SHORT PASSAGE ON HOW FIBRES ARE SPUN



HELPPP WILL MARK AS BRAINLIEST

Answers

Answer: Spun yarn is made by twisting staple fibers together

To make a cohesive thread Or “single”. Twisting fibers, into yarn in the process called spinning can be dated back to the upper Paleolithic. Yarn spinning was one of the first processes to be industrialized.

Explanation:

Whenever the same two elements form more than one
compound, the different masses of one element that combine
with the same mass of the other element are in the ratio of
small whole numbers.
TRUE
FALSE

Answers

Answer:

The answer is true

Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.

HELP
What type of bond is formed between the carbon and either oxygen in CO2?
A) Single
B) Double
C) Triple

Answers

It’s B Have Ah Good Day
It is B!! Good luck on you assignment

Which one of the following is NOT a proper unit for frequency? *
m·s–1
Hz
s–1
1/s

Answers

Answer:

m*s⁻¹.

Explanation:

Hello!

In this case, since the frequency measures how repetitive an event is per unit of time, for instance the laps a car drives every 5 minutes or something similar, we can infer it has units of event/time; in such a way, the unit m*s⁻¹ is not a proper unit of frequency because it is a proper unit of velocity which is the distance traveled per unit of time.

In such a way, Hz (hertz), s⁻¹ and 1/s are possible ways frequency can be represented.

Best regards!

What is the best-known feature of sedimentary
rocks?
A. ripple marks
B. fossils
C. graded bedding
D. cross-bedding

Answers

Answer:

option is (b)

Explanation:

please mark me as brilliant

The answers is b because it layers on so it is b


I need the answer multiple choice

Answers

Answer:

it's answer is

element of an atom ✌️

please help 10 points asap​

Answers

Answer:

opposite

Explanation:

Answer:

opposite

Explanation:

cu9c9ucoucucpucfpufupfpucupvpjvpucu

TRUE OR FALSE? Alloys are used more than pure metals because they are generally softer and less likely to react with air or water. WILL GIVE BRAINLIEST

Answers

Answer:

False

Explanation:

They’re used cause they’re generally harder than pure metals

Alloys are used much more than pure metals because they are generally stronger and less likely to react with air or water...

So I would say false

Why does the flask have to be closed during the hydrochloric acid and sodium carbonate reaction?

Answers

Answer:

The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.

Explanation:

The hydrochloric acid and sodium carbonate reaction was exothermic that caused the pressure to decrease. The flask has to be closed during the hydrochloric acid and sodium carbonate reaction as the resultant gas got trapped inside the closed flask.

In exothermic reactions, energy is produced in the form of heat or light.

What is one example of chemical weathering affecting a rock

Answers

Hydration is a type of chemical weathering where water reacts chemically with rock H20

Answer:

one example of chemical weathering is when carbon dioxide mixes with water.

Explanation:

when dioxide mixes with water it creates carbonation.

Trinitrotoluene (TNT, C7H5N3O6) undergoes complete combustion according to the following balanced chemical equation:
C7H5N3O6(s)+214O2(g)→7CO2(g)+32N2(g)+52H2O(l)

If 25.7 g of TNT is combusted in a 0.500 L container filled with O2 at a pressure of 7.02 bar and a temperature of 298 K, calculate the maximum mass of CO2 that could be produced.

Answers

Answer:

[tex]m_{CO2}=8.33gCO2[/tex]

Explanation:

Hello.

In this case, since the chemical reaction is:

[tex]C_7H_5N_3O_6(s)+\frac{21}{4} O2(g)\rightarrow 7CO_2(g)+\frac{3}{2} N_2(g)+\frac{5}{2} H_2O(l)[/tex]

Thus, since we have the initial moles of TNT:

[tex]n_{TNT}=25.7g*\frac{1mol}{227.13g} =0.113mol[/tex]

And the initial moles of oxygen given the ideal gas equation:

[tex]n_{O_2}=\frac{6.93atm*0.5L}{0.082\frac{atm*L}{mol*K}*298K}=0.142molO_2[/tex]

Given the 1:7 mole ratio between TNT and carbon dioxide and the 21/4:7 mole ratio between oxygen and carbon dioxide, we compute the yielded moles by each reactant:

[tex]n_{CO_2}^{by\ TNT}=0.113molTNT*\frac{7molCO_2}{1molTNT}=0.791molCO_2\\\\ n_{CO_2}^{by\ O_2}=0.142molO_2*\frac{7molCO_2}{21/4molO_2}=0.189molCO_2[/tex]

Thus, since oxygen yields less moles of carbon dioxide than TNT, we infer it is the limiting reactant, therefore, the produced mass of carbon dioxide is:

[tex]m_{CO2}=0.189molCO2*\frac{44.01gCO2}{1molCO2}\\\\m_{CO2}=8.33gCO2[/tex]

Best regards!

Which of the following statements is true regarding both theories and laws?

A: Change over time
B: Cannot be proven
C: Require consensus
D: Supported by observations

Answers

Answer:

D. Supported by observations

Explanation:

Because theories change over time, they both need to be proven, they do not go off of consensus, but they do need to be supported by observations.

HOPE IT HELPS❣️

Which step is part of a scientific investigation?
O designing a solution
O implementing the solution
O evaluating the solution
O communicating the findings

Answers

Steps of a scientific investigation include identifying a research question or problem, forming a hypothesis, gathering evidence, analyzing evidence, deciding whether the evidence supports the hypothesis, drawing conclusions, and communicating the results.

If the stack of bricks on the right has a mass of 240 kg, approximately what is the mass of the stack of bricks on the left?


A.
2400 kg
B.
720 kg
C.
320 kg
D.
480 kg

Answers

Answer:

720

Explanation: study island

Answer:

720

Explanation:

List 5 foods that contain bacteria?

Answers

yogurt, kefir, kombucha, sauerkraut, pickles, miso, tempeh, kimchi, sourdough bread and some cheeses.

The atom is one of the basic units of matter. Which part of the atom mostly determines the size of the atom?
a.Electrons

b.Nucleus

c.Neutrons

d.Protons

Answers

Answer:

Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. The separation that occurs because electrons have the same charge. The number of protons in the nucleus. The core electrons in an atom interfere with the attraction of the nucleus for the outermost electrons.

Explanation:

That would be B I believe, but please correct me if I'm wrong.

Which of these solutions are basic at 25 °C ? A:[OH−]=2.53×10−7 M B:[H3O+]=9.99×10−9 M C:[H3O+]=6.31×10−4 M

Answers

Answer: frfg6

Explanation: 655tyyt

every spring has an equilibrium position which statement describe a spring at it equilibruim position?

Answers

The elastic potential energy is zero. The net force acting on the spring is zero. Explanation: The equilibrium position of a spring is the position that the spring has when its neither compressed nor stretched - it is also called natural length of the spring.Mar

Draw and name the structures of the carboxylic acids and esters you put together using molecular models.

Answers

Answer:

This question is incomplete

Explanation:

However, when the carboxylic acids and esters put together are obtained, the procedure below can be followed in drawing and naming them.

For carboxylic acid,

1) it should be noted that the functional group here is -COOH which is drawn as -C = OH

      |

     OH

2) The carbon of the functional group is included among the carbon to be counted when naming the structure. For example, the compound below is propanoic acid.

CH₃CH₂COOH - As you can see that there are 3 carbons linked chain there.

3) As can be seen in (2) above, the suffix "oic" is used to name carboxylic acids

4) The carbon chain here is saturated (meaning there is no double or triple bond within the carbon chain)

Example of a structure of carboxylic acid is

H₃C - CH₂ - CH₂ - C = OH

                              |

                             OH

The structure above is a butanoic acid

For ester

1)The functional group here is -COO- . which can be drawn as

- C = O

   |

  O -

(meaning one oxygen atom is double bonded to the carbon and the other oxygen atom is bonded to another carbon chain)

2) The alkyl group attached to the oxygen atom is first of all mentioned before the carbon chain attached from the left is mentioned. For example, CH₃CH₂CH₂COOCH₂CH₃ is ethyl butanoate

3) As seen from (2) above, the suffix "oate" is used to end the name of esters

4) As also seen from (2) above, the carbon of the functional group is also included while counting the carbon chain of the parent name (butanoate).

5) The carbon chains here are also saturated.

Example of this ester is

CH₃CH₂C = O

              |

             O - CH₂CH₃

The name of this compound is ethyl propanoate

Why is it necessary to add concentrated HCl, then water, rather than a solution of HCl to the eudiometer tube

Answers

The reaction between concentrated acid and water can release a lot of heat. If a little water is added to a larger amount of acid, the heat can cause the small amount of water to boil very rapidly which then spatters some acid. ... It is recommended that acid should be added to water and not water to acid.

If we add water to a concentrated acid, then the solution may boil very violently, splashing concentrated acid. If add acid to water, the solution that forms is very dilute and a small amount of heat is released.

Why do we add acid to water?

When a strong acid is poured into water, it flows down the flask and mixes much better, so no boiling takes place. The addition of water to acid forms an extremely concentrated solution of acid initially. A large amount of heat is released and the solution may boil very violently, splashing concentrated acid out of the beaker and all this because the reaction is exothermic in nature.

The reason this takes place is due to a large amount of energy liberated in the hydration reaction of concentrated ions. Therefore, we add acid to water dropwise for the dilution with constant stirring and not water to acid directly.

If we add water to acid, then an exothermic reaction occurs and the solution may boil very violently. To form the dilute solution of any strong acid, you should add acid to water and the small amount of heat released is not sufficient to vaporize and spatter it.

Learn more about dilution of acid, here:

https://brainly.com/question/

#SPJ2

Will give brainliest, Look at the graph above. Compare it to the periodic table. What do you notice about the location on the periodic table of the elements that represent the high points

Answers

Answer:

We can see that the atomic radius decreases across every row.

Explanation:

I will comment more below.

The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.

The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.

Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.

Learn more: https://brainly.com/question/9352088

A 7.28 g sample of chromium metal was heated to produce chromium oxide. The weight of the compound was 10.63 g. What is the percent chromium in this compound?

Answers

Answer:

68.48%

Explanation:

The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.

In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:

%mass of Cr = mass of Cr/mass of Chromium oxide × 100%

%mass of Cr = 7.28/10.63 × 100

%mass of Cr = 0.6848 × 100

%mass of Cr = 68.48%

C is the element symbol for which element?
a. Carbon
b. Cadmium
c. Celenium
d. Chlorine​

Answers

Answer:

A) Carbon

Explanation:

the others are wrong its A

Answer:

A) carbon

Explanation:

carbon or simply c has an atomic number of 6 and it has an atomic mass of 12.01 amu. it belongs to group 4a

Question 2 of 25
Rain exists in which phase?
O A Liquid
O B. Solid
C. Plasma
D. Gas

Answers

Answer:

liquid

Explanation:

correct answer hope it helps

A 12 gram piece of Cu at 475 oC is placed in contact with a 15 gram piece of Cr at 265 oC.

Assume the two pieces of metal are the system and that there is no heat exchange between system and surrounding.

What is the final temperature of the two pieces of metal expressed in degree C?

Answers

Answer:

349.22°C

Explanation:

Let the final temperature of the two pieces of metal be x.

Now, the warmer metal which is C u reduces from 475°C to x. Thus Δt for C u is; Δt1 = 475 - x.

The cooler metal Cr increases in temperature from 265°C to x. Thus, it's change in temperature is Δt for Cr is; Δt2 = x - 265.

Now from conservation of energy, the amount of energy leaving the C u metal is equal to the amount of energy entering the Cr metal.

Thus;

q_lost = q_gain

Where;

q_lost = m1•c1•Δt1

q_gained = m2•c2•Δt2

Now, c1 & c2 are the specific heat capacity of C u and Cr respectively.

From online tables, c1 = 0.385 J/g°C and c2 = 0.46 J/g°C

We are given;

m1 = 12g and m2 = 15g

Thus;

12 × 0.385 × (475 - x) = 15 × 0.46 × (x - 265)

2194.5 - 4.62x = 6.9x - 1828.5

6.9x + 4.62x = 2194.5 + 1828.5

11.52x = 4023

x = 4023/11.52

x = 349.22°C

Other Questions
Find the LCM and GCF of 12 and 15. pls hurry and help me A recipe for 12 bran muffins calls for one cup of flour the number of muffins that can be made varies directly with the amount of flour used there are two 2/3 cups of flour available how many muffins can be made A Reuter's article on March 14, 2012 reported that Somali pirates had decided to cut their ransom demands so as to avoid costly hostage maintenance and increase flow rate. The article says that on average the pirates were holding 30 ships hostage, and each ship was held for 150 days.How many ships on average are the pirates capturing each month? (Assume a month is 30 days)- 10 ships per month- 30 ships per month- 6 ships per month- 1/5 ships per month Pleasee help, only if you know! me puede ayudar porfavor sequel nole entiendo nada a nandq b) Given that BC = 5 cm,work out the perimeter of the triangle. Give the percent equation AND answer for.......... 89% of what number is 14? 5 stars and a thank you Please complete the sentence with the correct word: She blank the shy kittenfrom under the couch. *totteredcoaxedunbridled PLZ HELP IM TIMEDDDRead the excerpt from The Diary of Anne Frank.Anne. Mouschi! Mouschi! Mouschi! (She picks up the cat, walking away with it. To Peter) I love cats. I have one . . . a darling little cat. But they made me leave her behind. I left some food and a note for the neighbors to take care of her . . . I'm going to miss her terribly. What is yours? A him or a her?Peter. He's a tom. He doesn't like strangers. (He takes the cat from her, putting it back in its carrier.)Anne (Unabashed). Then I'll have to stop being a stranger, won't I? What does this dialogue reveal about Anne?A.She is stubborn and impolite.B.She is clever and confident.C.She is quiet and understanding.D.She is sad and confused. Please help i will make the first correct answer BRAINLIEST I need help will mark BRAINLIEST if right!!!!!!!! Who took the blame in ancient Egypt for flooding, famine, and other disasters?ApriestsBfarmersinvadersDpharaohs 10 The rate of the reaction between hemoglobin (Hb)and carbon monoxide (CO) was studied at 20C.The following data were collected with allconcentration units in u mol/L. (A hemoglobinconcentration of 2.21 u mol/L is equal to2.21 x 10 mol/L.)[Hblo [CO),Initial Rate(u mol/L) (u mol/L) (u mol/Ls)2.211.000.6194.421.001.244.423.003.71(a) Determine the orders of this reaction withrespect to Hb and CO.(b) Determine the rate law.(c) Calculate the value of the rate constant.(d) What would be the initial rate for anexperiment with [Hb]o =3.36 u mol/L[CO] =2.40 4 mol/L? What is the value (in degrees) of angle Z1?55 The Kuiper Belt is estimated to be about 3,000,000 meters wide. Which value represents the estimated width of the Kuiper Belt, in meters, in scientific notation? Solve the equation 3(x-5) - 5x = -25 + 6x help me fast please I give brainliest answer Which practice can help prevent cross-contamination?A. storing ready-to-eat food below raw food in a coolerB. keeping food items in any covered durable containersC. using same equipment for prepping raw and ready-to-eat foodD. keeping single-use items in their original packagingE. cooling hot food by placing it on a prep counter overnight If you flip 3 coins what is the probability of NOT getting three Heads? P(not getting 3 Heads)