The melting point of H₂O(s) is 0 °C. Would you expect the melting point of H₂S(s) to be 85 °C, 0 °C or -85 °C.? Justify your choice

The number of moles of mercury can you get you collect and process the entire volume of 1250 m3 of the water in the pond is 8.7  × 10^-5 moles.

First, we must convert the concentration of mercury in the pond to molar concentration using the relation;

Mass concentration = Molar concentration × molar mass

Molar concentration = Mass concentration /molar mass

Molar mass of mercury = 201 g/mol

Molar concentration = 14 × 10^-9 g/201 g/mol = 6.97 × 10^-11 M

Volume of solution = 1250 m3 or 1250000 L

Number of moles = concentration × volume

Number of moles =  6.97 × 10^-11 M ×  1250000 L

Number of moles = 8.7  × 10^-5 moles

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Answer:

Cr

Explanation:

Cr goes from +3 to +6 and when it increases it means is being oxidized.

The element being oxidized in the redox reaction is Cr. Oxidation state helps to determine the amount of oxidation which an atom undergoes. An increase in oxidation state or number signifies oxidation has taken place.

A decrease in oxidation state depicts reduction has taken place. In this

scenario, the element Cr has a change in oxidation state from +3 to +6 which

signifies oxidation took place in the atoms of the element. This is why Cr will

be the right option.

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Answer:

Use the formula PV=nRT to get the temperature

Answer:

None of them

Explanation:

The number of moles in 75ml is 0.01875moles while in 25ml is 0.004375 and in 129 ml is 0.018705.

REMEMBER: Molarity is the number of moles per litre so in order to get the number of moles you multiply the molarity of the substance by the quantity of the substance in litres.

129 mL of 0.145 M solution of KCl solution has the same number of moles of KCl as 75.00 mL of 0.250 M solution of KCl. Therefore, option B is correct.

Molarity is defined as the number of moles of a solute in one liter of solution. A solution's molarity is also known as its molar concentration.

To calculate the molarity of a solution, divide the number of moles of solute by the total volume of solution in liters.

Molarity is a concentration unit that is defined as the number of moles of dissolved solute per liter of solution. Molarity is expressed as the number of millimoles per milliliter of solution when the number of moles and volume are divided by 1000.

Given:

number of mol = M ×V

= 0.250 M × 0.0750 L

= 1.87 × 10^-2 mol

volume, V = 1.29*10^2 mL

= 0.129 L

use:

number of mol,

n = Molarity × Volume

= 0.145 × 0.129

= 1.87 × 10^-2 mol

Thus, option B is correct.

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Answer:

la primera va con la última

0.04 moles of iodide is required to precipitate all the lead II ions from  25.0 mL of a 1.6 M Pb(NO3)2 solution.

The reaction equation is;

2KI(aq) + Pb(NO3)2(aq) -------> PbI2(s) + 2KNO3(aq)

The net ionic equation is;

Pb^2+(aq) + 2I^-(aq) ------> PbI2(s)

Number of moles of Pb(NO3)2  = 25/1000 L ×  1.6 M = 0.04 moles

Number of moles of Pb^2+ = 0.04 moles /2 = 0.02 moles

Since 2 moles of iodide reacts with 1 mole of Pb^2+

x moles of iodide reacts with 0.02 moles of Pb^2+

x =  2 moles × 0.02 moles/ 1 mole

x = 0.04 moles of iodide

Hence,  0.04 moles of iodide is required to precipitate all the lead II ions from  25.0 mL of a 1.6 M Pb(NO3)2 solution.

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Answer:

New volume = 6.0L

Explanation:

Make a list of variables given in the question, and what we want to find:

Initial volume (L) = Vi = 3.1

Initial temperature (K) = Ti = 193

New temperature (K) = Tn = 374

New volume (L) = Vn

We have volumes and temperatures given and we're talking about gas, the equation including both these variables that should come to mind is the ideal gas equation:

PV = nRT

P = pressure (Pa)

n = number of moles

R = gas constant = 8.31

Now, we construct an equation we can solve to get the new volume:

P(Vn) = nR(Tn)

And insert the values we know:

P(Vn) = n(8.31)(374)

P(Vn) = n·3107.94

The equation contains 3 unknown variables;

We should first try to see if we can eliminate the 2 we are not interested in, namely P and n;

What we should recognise is that the pressure and number of moles will not change upon warming the balloon;

Firstly, heating the gas inside the balloon doesn't add anything to the balloon, i.e. doesn't increase the moles of gas, it simply raises the energy of the gas particles already within the balloon, so n will not change;

Secondly, I think there is a mistake in the question, it should read "assume constant pressure" in the brackets, since the temperature does change, which we are told;

Also, we can assume normal atmospheric pressure inside and outside the balloon as would be the case ordinarily;

What we want to do with this information is rearrange the equation we constructed to have these 2 constant or unchanging variables on one side and everything else on the other, so:

[tex]\frac{P}{n} = \frac{3107.94}{V_{n} }[/tex]

Next, we construct an equation for the balloon before warming:

P(Vi) = nR(Ti)

P(3.1) = n(8.31)(193)

P·3.1 = n·1603.83

Once again, rearrange to get P and n on one side of the equation and everything else on the other:

[tex]\frac{P}{n} = \frac{1603.83}{3.1} \\\\ \frac{P}{n} = 517.364516[/tex]

Now, we have two equations for P/n, we can eliminate P/n since both these values remain the same before and after warming the balloon as previously established:

[tex]\frac{3107.94}{V_{n} } = \frac{P}{n} = 517.364516 \\\\ \frac{3107.94}{V_{n} } = 517.364516 \\\\[/tex]

Now, rearrange and solve for Vn:

[tex]\frac{3107.94}{V_{n} } = 517.364516 \\\\ V_{n} = \frac{3107.94}{517.364516} \\\\ V_{n} = 6.00725...[/tex]

Vn = 6.0L

Answer:

answer is 4.6×10 with exponent 7

Answer:

[tex]4.6\times10^{-7}[/tex]

Explanation:

Remember that if the decimal point is to the right then the exponent is a negative.

[tex]4.6\times10^{-7}[/tex]

Move the decimal point to the left:

[tex].0.0.0.0.0.0.4.6[/tex]

[tex].0.0.0.0.0.0.4.6=0.00000046[/tex]

Hope this helps

Answer:

Biotic and abiotic are the two essential factors responsible for shaping the ecosystem. The biotic factors refer to all the living beings present in an ecosystem, and the abiotic factors refer to all the non-living components like physical conditions (temperature, pH, humidity, salinity, sunlight, etc.) and chemical agents (different gases and mineral nutrients present in the air, water, soil, etc.) in an ecosystem. Therefore, both the abiotic and biotic resources affect survival and reproduction process.

Furthermore, both these components are reliant on each other. Suppose if one of the factors is removed or altered, its repercussions will be faced by the entire ecosystem. Without a doubt, abiotic factors directly affect the survival of organisms. Read on to explore what role do abiotic and biotic resources play in the ecosystem.

The two primary forces influencing the ecosystem are biotic and abiotic. The terms "biotic factors" and "abiotic factors" describe the various living and non-living elements of an ecosystem, respectively.

A living thing that alters its surroundings is referred to as a biotic factor. Examples of organisms found in a freshwater habitat include algae, fish, amphibians, and aquatic plants. A particular ecosystem is the result of the interaction of biotic and abiotic components.

All living things, including people, fungi, and bacteria as well as animals and plants, are considered to be biotic factors. For each species to reproduce and to meet basic needs like food, the interactions between numerous biotic variables are vital.

Due to the fact that these organisms "create" food using inorganic materials and energy sources, the producers are biotic elements that are crucial to an ecological system. Without them, life might not be able to exist.

Thus, The two primary forces influencing the ecosystem are biotic and abiotic.

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Answer:

11000 g/L

Explanation:

Since density is mass divided by volume, find the volume of the metal ball by subtracting the initial volume of water in the graduated cylinder from the ending volume. In this case, the volume would be 17.90 mL - 16.05 mL =  1.85 mL = 0.00185 L. Then using the formula for density, calculate 20.350 g / 0.00185 L = 11000 g/L.

Density is an intensive property as it does not depend on the quantity of the substances Whereas mass and volume are extensive property. Therefore, the density of the metal ball is 11000 g/L.

Density tells about the compactness of the substances, how much dense is the substances in other words. Object that is more denser than water they just sink in the water.

Mathematically,

Density = Mass of the metal ball ÷volume marked on the graduated cylinder

volume=ending volume- initial volume of water in the graduated cylinder            

            =17.90 mL - 16.05 mL

            =  1.85 mL

            = 0.00185 L.

substituting all the given values in the above equation, we get

density=  20.350 g / 0.00185 L

            = 11000 g/L.

Therefore, the density of the metal ball is 11000 g/L.

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Answer:

1.1 million pounds

Explanation:

Answer:

1.1 million pounds

Explanation:

that's a lot of water above us!!

% Composition of elements:

Atomic mass of given elements:

Now, divide % composition by Atomic mass:

[tex]\footnotesize\implies Mg = \dfrac{\% \: Composition}{Atomic \: mass} = \dfrac{75}{24} = \bf 3.125[/tex]

[tex]\footnotesize\implies O = \dfrac{\% \: Composition}{Atomic \: mass} = \dfrac{25}{16} = \bf 1.5625[/tex]

Simplest Ratio:

[tex]\footnotesize\implies Mg = \dfrac{3.125}{1.5625} = 2[/tex]

[tex]\footnotesize\implies O = \dfrac{1.5625}{1.5625} = 1[/tex]

Empirical Formula:

[tex]\footnotesize\implies \underline{ \boxed{ \red{ \bf Empirical \: Formula = Mg_2O}}}[/tex]

The empirical formula will be [tex]Mg_{2}[/tex] .

The simplest entire number fraction of atoms contained in a chemical molecule is its empirical formula.

Calculation of empirical formula:

It is given that, composition of Mg = 75 %, composition of oxygen  = 25%.

It is known that, atomic mass of Mg = 24 g, atomic mass of oxygen = 16g.

By dividing % composition by atomic mass of given elements:

Mg = % composition / %atomic mass

= 75 / 24

= 3.125

Oxygen (O) = % Composition / atomic mass

= 25 / 1.56

Now, calculate simplest ratio of Mg and O.

For Mg = 3.125 / 1.56

= 2.

For O = 1.56 / 1.56

= 1

So, the empirical formula will be [tex]Mg_{2}O[/tex].

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Answer:The plates are not fixed but are constantly moving atop a layer of solid and molten rock called the mantle. The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. ... A hotspot is a place in the middle of a tectonic plate where hot magma rises.

Explanation:

Answer:

[tex]11 \times 6.022 \times {10}^{23} \\ = 66.242\times {10}^{23} \: of \: \\ water \: molecules[/tex]

Answer:

B

Explanation:

Option B is the correct answer. When you add 7 in front of the O2 in the left side, and then you add 4 and 6 in front of NO2 and H2O respectively, the number of oxygen atoms is the same in both sides.

Answer:

i dont speak mexican

Explanation:

The molarity of the acid, HCl solution is 0.103 M

We'll begin by calculating the number of mole in 0.2329 g of Na₂CO₃

Mass of Na₂CO₃ = 0.2329 g

Molar mass of Na₂CO₃ = (23×2) + 12 + (16×3) = 106 g/mol

Mole = mass / molar mass

Mole of Na₂CO₃ = 0.2329 / 106

Na₂CO₃ + 2HCl —> 2NaCl + H₂O + CO₂

From the balanced equation above,

1 mole of Na₂CO₃ reacted with 2 moles of HCl.

Therefore,

0.0022 mole of Na₂CO₃ will react with = 0.0022 × 2 = 0.0044 mole of HCl

Mole of HCl = 0.0044 mole

Volume = 42.87 mL = 42.87 / 1000 = 0.04287 L

Molarity = mole / Volume

Molarity of HCl = 0.0044 / 0.04287

Thus, the molarity of the acid, HCl solution is 0.103 M

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Answer:

No it has not.

Explanation:

The actual chemical compound has not changed, the materials have mixed but no reaction has taken place. Blowing the bubbles causes a physical change. Hope this helped!

Mixing soap and water and forming bubbles is a physical change as there is no change in composition.

Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.

Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.

They involve only rearrangement of atoms and are often characterized to be changes which are reversible.

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This question is asking for a method for the determination of the freezing point in a solution that does not have a noticeable transition in the cooling curve, which is basically based on a linear fit method.

The first step, would be to understand that when the transition is well-defined as the one on the attached file, we can just identify the temperature by just reading the value on the graph, at the time the slope has a pronounced change. For instance, on the attached, the transition occurs after about 43 seconds and the freezing point will be about 4 °C.

However, when we cannot identify a pronounced change in the slope, it will be necessary to use a linear fit method (such as minimum squares) to figure out the equation for each segmented line having a significantly different slope and then equal them so that we can numerically solve for the intercept.

As an example, imagine two of the segmented lines have the following equations after applying the linear fit method:

[tex]y=-3.5 x + 25\\\\y=-0.52 x + 2[/tex]

First of all, we equal them to find the x-value, in this case the time at which the freezing point takes place:

[tex]-3.5 x + 25=-0.52 x + 2\\\\-3.5 x+0.52 x =2-25\\\\x=\frac{-23}{-2.98}=7.72[/tex]

Next, we plug it in in any of the trendlines to obtain the freezing point as the y-value:

[tex]y=-3.5 (7.72) + 25\\\\y = 1.84[/tex]

This means the freezing point takes place after 7.72 second of cooling and is about 1.84 °C. Now you can replicate it for any not well-defined cooling curve.

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Answer:

=> moles = Given mass/molar mass

=> 0.787 = Given mass/(39 + 12 + 14)

=> 0.787 = Given mass/65

=> mass = 0.787 × 65

=> mass = 51.155 g

Answer:

Mass Number

Explanation:

In nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.

Please vote brainliest!

Answer:

Natural source of light

Explanation:

Answer:

Mercury has a relatively high vapour pressure and the highest volatility of any metal, vapourizing to become a colourless, odourless gas. The metal is a fair conductor of electricity, but a poor conductor of heat. Mercury's atomic number is 8.

Answer:Charge on X  = (+ 2)

Explanation:

Charge on one Cl = -1

So Charge on two Cl = -2

The molecule = Neutral = 0 charge

So, to make total charge = 0 , the X should have +2 charge

XCl2 = +2 -2 = 0

X = +2

Alkaline earth metals(Be , Mg , Ca , Sr) form such type of compounds

Explanation:

Answer:

XF3 is our compound. X is unknown For the problem I am using the periodic table at this ...

Explanation:Solution for Element X is an element in period 3. Identify X given that in the molecule XH3, it exhibits hybridization sp2 . Indicate the symbol and not ...

Two or more than two atoms with different physical or chemical properties can not combine together to form an element. The element X  in period 4 with covalency 3 is Arsenic (As).

Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same. The periodic table is divided into groups and periods. depending on the number of valence electrons and the number of outermost orbit respectively.

In the given compound XH[tex]_3[/tex], the covalency of X is 3, means the valence electrons in the outermost shell of element X is 3. The only group that have valence electron 3 is group 15  that is nitrogen family. In the fourth period of group 15 we find Arsenic element.

Therefore the element X  in period 4 with covalency 3 is Arsenic (As).

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Answer:

Na2S

Explanation:

hope this helps

Answer:

This tells you that one mole of sulfur atoms, S , has a mass of 32 g

Answer:

6am

Explanation:

answer this please thank you