I NEED HELPPP THIS DUE TODAY!!!! IT IS URGENT!!

Answer:

46%

Explanation:

When solving this problem we have to note that the amount of salt (in grams) before isolation and after isolation are equal. If [tex]V_1[/tex] represents its volume before isolation and [tex]V_2[/tex] its volume after isolation then:

[tex]2.1 \frac{g}{L} *V_1=3.89\frac{g}{L} *V_2\\\\\frac{V_2}{V_1} =\frac{2.1}{3.89}\\\\\frac{V_2}{V_1} =0.54\\\\This\ means\ after \ isolation\ the\ volume\ of water\ is\ 54\%\ of\ its\ original\ value.\\\\The\ amount\ of\ evaporation=1-\frac{V_2}{V_1} =1-0.54=0.46=46\%\\\\The\ amount\ of\ evaporation=46\%[/tex]

Answer:

Option C is correct = ₈₅At²²⁰

Explanation:

Given radioactive decay shows the beta emission.

²²⁰₈₄Po    ₈₅At²²⁰  +  ⁰₋₁e ⁻

Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.

Properties of beta radiations:

1) They can travel in air in few meter distance.

2) These radiations can penetrate into the human skin.

3) The mass of beta particle is smaller than the alpha particles.

4) The sheet of aluminium is used to block the beta radiation

¹⁴₆C → ¹⁴₇N + ⁰₋₁e ⁻

The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.

Answer:

Frogs have three circuits for their circulation, unlike humans who only have two. Like humans, however, frogs have a systemic circuit, which pumps oxygenated blood throughout the body. The pulmonary circuit moves blood to the lungs to pick up oxygen.

Explanation:

Answer:

A

Explanation:

Answer:

A) They are all acidic.

Explanation:

All 3 of those have acidic qualities in the drink.

Answer:

They are all acidic

Explanat

Answer:

HC₉H₇O₄(aq) + H₂O(l) ⇄ C₉H₇O₄⁻(aq) + H₃O⁺(aq)

Explanation:

A weak acid as aspirin, HC₉H₇O₄, is in equilibrium with water as follows:

This is the chemical equation that describes the process.

As you can see, not all aspirin is dissolved, just a part that is converted in its conjugate base (A weak acid doesn't dissociate completely!).

Also, the pH is decreasing because the hydronium ion (H₃O⁺) is produced in the equilibrium (Remember, if you have an increasing in H₃O⁺ concentration the pH will decreases and vice versa).

Answer:

Explanation:

Finding Limiting reactant:

Convert all reactant data to moles, divide by respective coefficient => smaller value is the limiting reactant.

Given      2KCl      +     CaF₂ => 2KF + CaCl₂

            55.1mole      46.7mole

(55.1/2) = 27.55          (46.7/1) = 46.7

Limiting reactant is KCl b/c smaller value after dividing by respective coefficients. CaF₂ will be in excess when rxn consumes all KCl.

Moles KF = 55.1 mole as coefficients of two substances in balanced equation are equal.

Answer:

2

Explanation:

Hello!

The answer is that they are a source of energy!

Hope this helps!

Answer:

B. technetium

Explanation:

Answer:

element

Explanation:

the gas inside a noble gas is made of only one neon atom and is less reactive and would not likely combine with any other element

Answer:

Pressures and temperatures

Explanation:

In deciding the new substances that develop in a metamorphic stone, pressures and temperatures are major factors. Under various conditions of pressure and temperature, various minerals form.

Metamorphic rocks are classified that, extreme heat and strain, have altered shape. Metamorphic derives from the terms meta and morph in german. Meta means alteration and morph means shape. So, to alter shape, we get metamorphosed significance.

Answer:

Explanation:

Given 2H₃PO₄ + 3Ca ⇒ 3H₂ + Ca₃(PO₄)₂

          27.4g

       =(27.4g/98g/mol)

       = 0.280 mole H₃PO₄ used

Ca Used:

Rxn Ratio H₃PO₄ : Ca => 2:3

∴ moles Ca used = 3/2(0.280) mole Ca =0.420 mole Ca

grams Ca used = 0.420 mole Ca x 40 g/mole = 16.8 grams Ca used

Grams H₂ Produced:

Rxn Ratio H₃PO₄ : H₂ => 2:3 => moles H₂ produced = 3/2(0.28 mole H₂) = 0.420 mole H₂ = (0.420 mole H₂ x 2.02 g/mole) = 0.8484 grams H₂(g) Produced.

Moles Ca₃(PO₄)₂ Produced:

FWt Ca₃(PO₄)₂ = 310 g/mole

Rxn Ratio H₃PO₄ : Ca₃(PO₄)₂  => 2:1

∴moles Ca₃(PO₄)₂ Produced = 1/2(moles H₃PO₄ used)

= 1/2(0.28 mole) = 0.14 mole Ca₃(PO₄)₂  

If you want grams Ca₃(PO₄)₂, multiply moles Ca₃(PO₄)₂ by formula weight.

Answer: Water as its the universal solvent

Answer:

dinosaur footprint

Explanation:

dinosaur footprint because the deffinition of trace fossil is a fossil of a foot print

Answer: Dinosaur footprint should be correct!

Explanation: As in the name, trace footprints are practically just traces, so a Dino print is a perfect example! The dinosaur left a trace, leaving evidence about it, for science to study:) please let me know if this helps! :)

A balanced chemical equation for the standard formation reaction of gaseous hydrogen iodide is H₂(g) + I₂(g) → 2HI(g).

Balanced chemical reactions are those in which equal amount of each entities will present on both sides of the reaction.

Formation of gaseous hydrogen iodide takes place by the mixing od hydrogen gas and iodine gas and balanced chemical equation for the formation of HI will be represented as:

H₂(g) + I₂(g) → 2HI(g)

So, required equation is H₂(g) + I₂(g) → 2HI(g).

To know more about balanced equations, visit the below link:
https://brainly.com/question/26694427

Answer:

chemically resistant

durable

non-reactive

easy to manufacture

Explanation:

Plastics are polymer materials which can be moulded or shaped into any desired shape when hot. There are two types of plastics; thermoplastics and thermo sets.

Most plastics are easily manufactured. They are light weight materials , chemically stable, durable and do not undergo chemical reactions upon prolonged exposure to the atmosphere.

The study of chemicals is called chemistry.

The correct answer is options B, C, and E

The plastic is made by the carbon by joining with itself by a covalent bond and this property of carbon is known as catenation.

In today's time plastic is used all over the world and it is because of the following reasons.

Hence, the correct answer is B, C, and E.

For more information, refer to the link:-

https://brainly.com/question/25305623

Answer:

Mitosis meiosis

Explain:

Mitosis is where the cell splits into 2 more cells (diploid)

Meiosis is where the cell splits into 2, and then split again, making 4 (haploid)

Answer:

Barium

Explanation:

Answer:

hello your question lacks the required reaction pairs below are the missing pairs

Reaction system 1 :

A + B ⇒ D  [tex]-r_{1A} = 10exp[-8000K/T]C_{A}C_{B}[/tex]

A + B ⇒ U [tex]-r_{2a} = 100exp(-1000K/T)C_{A} ^\frac{1}{2}C_{B} ^\frac{3}{2}[/tex]

Reaction system 2

A + B ⇒ D  [tex]-r_{1A} = 10exp( -1000K/T)C_{A}C_{B}[/tex]

B + D ⇒ U  [tex]-r_{2B} = 10^9exp(-10000 K/T) C_{B}C_{D}[/tex]

Answer : reaction 1 : description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1

condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2

reaction 2 :

description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1

condition to maximize selectivity:

to increase selectivity the concentration of D should be minimal

Explanation:

Reaction system 1 :

A + B ⇒ D  [tex]-r_{1A} = 10exp[-8000K/T]C_{A}C_{B}[/tex]

A + B ⇒ U [tex]-r_{2a} = 100exp(-1000K/T)C_{A} ^\frac{1}{2}C_{B} ^\frac{3}{2}[/tex]

the selectivity of D is represented  using the relationship below

[tex]S_{DU} = \frac{-r1A}{-r2A}[/tex]

hence SDu = 1/10 * [tex]\frac{exp(-800K/T)}{exp(-1000K/T)} * C_{A} ^{0.5} C_{B} ^{-0.5}[/tex]

description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1

condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2

Reaction system 2

A + B ⇒ D  [tex]-r_{1A} = 10exp( -1000K/T)C_{A}C_{B}[/tex]

B + D ⇒ U  [tex]-r_{2B} = 10^9exp(-10000 K/T) C_{B}C_{D}[/tex]

selectivity of D

[tex]S_{DU} = \frac{-r1A}{-r2A}[/tex]

hence Sdu = [tex]1/10^7 * \frac{exp(-1000K/T)}{exp(-10000K/T)} *\frac{C_{A} }{C_{D} }[/tex]

description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1

condition to maximize selectivity:

to increase selectivity the concentration of D should be minimal

Answer:

[tex]\mathbf{FeCl_3}[/tex] is the lewis acid

[tex]\mathbf{CH_3COCl}[/tex] is the lewis base

Explanation:

The Lewis acid is a compound capable of accepting a doublet of electrons and which has an electronic gap on its valence layer.

The lewis base is a compound capable of donating a doublet of electrons.

A Lewis acid associates with a Lewis base through a covalent bond (sharing of two electrons between two atoms). The reaction between an acid and a Lewis base produces a compound called the Lewis adduct.

We can see the illustration of the diagrammatic expression in the image attached below.

Answer: No

Explanation: Some scientists have declared that mineral deposits containing important non renewable resources such as copper and zinc will be exhausted in a few decades if consumption does not decrease.

Answer:

[tex]m_{H_2O}=6.84gH_2O[/tex]

Explanation:

Hello.

In this case, for 5.17 g of hexane (molar mass = 86 g/mol) and 16.5 g of oxygen (molar mass =32 g/mol), we have the reaction:

[tex]C_6H_{14}+\frac{19}{2} O_2\rightarrow 6CO_2+7H_2O[/tex]

Next, via the 1:7 mole ratio of hexane to carbon dioxide and 19/2:7 mole ratio of oxygen to carbon dioxide, we compute the yielded mass of water (molar mass = 18 g/mol) as its theoretical yield by the two masses of reactants and we infer that the limiting reactant is that yielding the fewest moles of product:

[tex]m_{H_2O}^{by\ Hexane}=5.17gC_6H_{12}*\frac{1molC_6H_{12}}{86 gC_6H_{12}} *\frac{7molH_2O}{1molC_6H_{12}}*\frac{18gH_2O}{1molH_2O} =7.57gH_2O\\\\m_{H_2O}^{by\ Oxygen}=16.5gO_2*\frac{1molO_2}{32gO_2} *\frac{7molH_2O}{\frac{19}{2}molO_2 }*\frac{18gH_2O}{1molH_2O} =6.84gH_2O[/tex]

Whereas it is evidenced that oxygen yields the fewest grams of water, therefore, it is the limiting reactant and the theoretical yield of water is:

[tex]m_{H_2O}=6.84gH_2O[/tex]

Best regards!

Answer:

d = 0.057 g/mL

Explanation:

Given that,

The dimensions of a rectangular metal is 25 dm long, 525 mm wide, and 1.5 m high.

The weight of the metal is 250 lb

We need to find the density of the metal in g/mL.

1 lb = 453.592 g

250 lb = 113398 g

Volume of the block,

V = 25 dm× 525 mm×1.5 m

Since, 1 dm = 0.1 m, 1mm = 0.001 m

V = 2.5 m× 0.525 m× 1.5 m

V = 1.9668 m³

Also, 1 m³ = 1968000 mL

So,

density = mass/volume

density = 113398 g/1968000 mL

= 0.057 g/mL

So, the density of a rectangular metal is 0.057 g/mL.

Answer:

C.Potassium

Explanation:

As we know that Potassium is a mineral also at the same time it is an electrolyte. It helps for muscles work involves the muscles so that the heartbeat and breathing could be controlled.

Now as per the periodic table on an early basis that depends upon the similar properties so the element that should be grouped with the sodium is Potassium

hence, the option c is correct

According to the early periodic table the element that has been grouped together with Na has been Potassium. Thus, option C is correct.

The early periodic table has been consisted of the elements that has been arranged based on the increasing order of the atomic mass. The grouping of the elements has been performed based on the similarities with the elements.

The sodium has been the electrolyte that has been responsible for maintaining the electrolyte balance in the human body. The sodium has been the smaller size element with being highly reactive.

The element that has also been small size with high reactive, and has been able to maintain the body electrolyte balance has been Potassium.

Thus, according to the early periodic table the element that has been grouped together with Na has been Potassium. Thus, option C is correct.

For more information about the early periodic table, refer to the link:

https://brainly.com/question/9915445

Answer:

See explanation and image attached

Explanation:

If we look at the question closely, we will discover that two molar equivalents of hydrogen gas was used to obtain cyclooctane rom X. This implies that the compound X is an alkyne and it must be cyclooctyne since the hydrogen serves to reduce the triple bond and yield the corresponding alkane.

This is confirmed by the second statement which is ozonolysis of the X with zinc in aqueous acid which gave two molar equivalents of the same dialdehyde.

Image credit: Chem spider

Answer:

it decreased

Explanation:

the distance stayed the same, and if it takes him longer to get somewhere than it did another day, it would mean his speed decreased.