what happens to water as it freezes? i know the answer is either b or c, but i’m not sure which one it is :(

Answer:

Ka = 9.2x10⁻⁷

Explanation:

The equilibrium of carbonic acid in water is:

H₂CO₃ ⇄ HCO₃⁻ + H⁺

Where Ka is defined as:

Ka = [HCO₃⁻] [H⁺] / [H₂CO₃]

The equilibrium concentration of the species is:

[H₂CO₃] = 1.9x10⁻² - X

[HCO₃⁻] = X

[H⁺] = X

As pH is -log[H⁺]

3.88 = -log[H⁺]

1.318x10⁻⁴ = [H⁺] = X

Replacing:

[H₂CO₃] = 1.9x10⁻² - 1.318x10⁻⁴ = 1.8868x10⁻²

[HCO₃⁻] = 1.318x10⁻⁴

[H⁺] = 1.318x10⁻⁴

Replacing in ka equation:

Ka = [1.318x10⁻⁴] [1.318x10⁻⁴] / [1.8868x10⁻²]

Answer: 9.2 x 10^-7

Explanation:

Answer:

location of earthquakes epicenter

Explanation:

The location of an earthquake's epicenter  is indirect evidence used to study Earth's interior. Therefore, option C is correct.

The Earth's interior is made up of four layers, three solid and one liquid—molten metal that is nearly as hot as the sun's surface. The deepest layer is a solid iron ball with a diameter of about 1,500 miles.

The Earth's core is significant for three reasons: (1) it generates the planet's magnetic field; (2) it contains information about the planet's early history of accretion; and (3) it contains information about the planet's earliest history of accretion.

Geologists use an indirect method as well. They use seismic waves instead of knocking on walls. Seismic waves are produced when earthquakes occur. Geologists study seismic waves and how they travel through the Earth.

Thus, option C is correct.

To learn more about the Earth's interior, follow the link;

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Answer:

15 g

Explanation:

1. According to the Law of Conservation of Mass, the sum of the products should be 105 g because 70 g + 35 g = 105 g.

2. If 90g of solution was produced and there's supposed to be 105 g, then the remaining grams would be equal to the mass of the gas.

3. 105 g - 90g = 15 g

Answer:

D. Two or more elements or compounds that are mixed together but not chemically bonded.

Explanation:

Mixture is unique as it is not chemically bonded and individual entities such as elements or compounds keep their unique identities.

Answer:

Mixture consists of two or three elements or compounds that are mixed together but not chemically bonded.

Answer:

smaller volume ⇒ Crowded particles ⇒ More collisions  ⇒ Higher pressure

Explanation:

Smaller the volume , more crowed the particles . Then the particles will have rapid collisions so the free mean path is decreased , hence the pressure will be increased as follows

[tex]P=\frac{K_bT}{\sqrt{2}\pi d^2\lambda }[/tex]

where λ is mean free path , P is pressure .

The sequence the represent the relationship between pressure and volume of an ideal gas is: smaller volume right arrow Crowded particles right arrow More collisions right arrow Higher pressure

The kinetic molecular theory made five postulates which are used to explain the behaviour of gases.

From the postulates, he uses the kinetic molecular theory to explain Boyle's Law because the majority of a gas's volume in space is usually empty and may be compressed.

So, when a gas is compressed without affecting its temperature, the average kinetic energy of the gas particles remains constant. The particles continue to flow at the same rate, but the container has reduced.

As a result, the particles go from one end of the container to another in less time. This suggests they're hitting the barriers (collision) more frequently. Each and every increase in the frequency of collisions with the walls, thus, results in an increase in the gas's pressure.

Hence, as the volume of a gas decreases, the pressure of the gas increases.

Learn more about the Kinetic molecular theory here:

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Answer:

B

Explanation:

Answer:

The Solar Nebula Theory accounts for the creation of solar systems, stars, and planets. The theory accounts for planet composition by stating that iron compounds, silicates, and dust clump together to form planetesimals. Because of the proximity of the sun, ices and gases cannot condensate near them, so they do not become gas giants. The planetesimals then collide together due to gravity and collect to form our rocky planets.

Explanation:

Answer:

The information from Mariner 6 and Mariner 7

Explanation:

Because they had not been launched yet

Answer: The chemical formula for lead (II) iodide is [tex]PbI_2[/tex]

Explanation:

Lead (II) iodide is a ionic compound because it are formed by transference of electrons between metals and non metals.The bond formed between a metal and a non-metal is always ionic in nature.

For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

The nomenclature of ionic compounds is given by:

1. Positive is written first followed by the oxidation state of metal in roman numerals in square brackets.

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

The chemical formula for lead (II) iodide is [tex]PbI_2[/tex]

To calculate the actual heat, I'd use calorimetric to weigh a sample mass. I 'd calculate the mass of a material sample. At a specified temperature, I will heat the material. I should position the heated material inside a calorimeter for coffee cup containing an initially established mass of water. I 'd wait for the weather to stabilize and then measure the difference in weather. To assess the sum of energy consumed, I will use the increase in water temperatures. For measure real heat I will use the sum of energy per material, weight, and temperature shift.

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Hope this helps!

Brainliest would be great!

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With all care,

07x12!

Answer:

-I would use calorimetry to determine the specific heat.

-I would measure the mass of a sample of the substance.

-I would heat the substance to a known temperature.

-I would place the heated substance into a coffee-cup calorimeter containing a known mass of water with a known initial temperature.

-I would wait for the temperature to equilibrate, then calculate temperature change.

-I would use the temperature change of water to determine the amount of energy absorbed.

-I would use the amount of energy lost by substance, mass, and temperature change to calculate specific heat.

Answer: 2.48×10^-17 J

Explanation:

Given the following :

Wavelength = 8nm (8 x 10^-9 m)

Energy(e) of X-ray =?

Energy=[speed of light(c) × planck's constant (h)] ÷ wavelength

Speed of light = 3×10^8m/s

Planck's constant = 6.626×10^-34 Js

Wavelength = 8 x 10^-9 m

Energy = [(3×10^8) * (6.626×10^-34)] / 8 x 10^-9

Energy = [19.878×10^(8-34)] / 8 x 10^-9

Energy = 2.48475 × 10^(-26+9)

Energy = 2.48×10^-17 J

Answer: 2.48×10^-17 J

Explanation: a pex

Answer:

[tex]\large \boxed{\text{0.88 L}}[/tex]

Explanation:

The temperature and amount of gas are constant, so we can use Boyle’s Law.

[tex]p_{1}V_{1} = p_{2}V_{2}[/tex]

Data:

[tex]\begin{array}{rcrrcl}p_{1}& =& \text{1.34 atm}\qquad & V_{1} &= & \text{ 0.56 L} \\p_{2}& =& \text{0.85 atm}\qquad & V_{2} &= & ?\\\end{array}[/tex]

Calculations:  

[tex]\begin{array}{rcl}\text{1.34 atm} \times \text{0.56 L} & =& \text{0.85 atm} \times V_{2}\\\text{0.750 L} & = & 0.85V_{2}\\V_{2} & = &\dfrac{0.750}{0.85}\\\\& = &\textbf{0.88 L}\\\end{array}\\\text{The balloon's new volume is $ \large \boxed{\textbf{0.88 L}}$}[/tex]

Answer:

so mass in gram=560grams

Explanation:

number of moles=10moles

molar mass=56grams/moles

mass in gram of Fe=?

as we know that

[tex]number of moles=\frac{mass in gram}{molar mass}[/tex]

evaluating the formula

number of moles×molar mass=mass in gram

mass in gram=10moles×56grams/moles

mass in gram=560grams

i hope this will help you :)

Answer:

The vinegar is not enough to neutralize the pool.

Explanation:

The [OH⁻] in the pool is 1.0x10⁻¹mol / L. To know how many moles of OH⁻ are in the solution, you must calculate volume of the pool thus:

V(pool) = πr²h

Where r, radius is d/2 = 12m/2 = 6m  and h is deep of the pool = 10m

V(pool) = π(6m)²*10

V(pool) = 1131m³

As 1m³ = 1000L:

1131m³  × (1000L / 1m³) = 1131000L in the pool.

And moles of OH⁻ are:

1.0x10⁻¹mol / L ₓ 1131000L = 131100 moles of OH⁻ are in the pool

The neutralization of OH⁻ with H⁺ is:

OH⁻ + H⁺ → H₂O

That means to neutralize the pool you must add 131100 moles of H⁺.

The H⁺ concentration in a vinegar pH = 2 is:

pH = -log [H⁺]

2 = -log [H⁺]

1x10⁻²M = [H⁺]

4L are just 4x10⁻² moles of [H⁺]. As you need 131100 moles of H⁺:

Answer:

Volume is 0.0247L

Explanation:

This question involves the use of Boyle's law which states that the volume of a given mass of gas is inversely proportional to it's pressure provided that temperature remains constant.

Mathematically,

v = k/p

K = VP

P1V1 = P2V2 = P3V3 = .........=PnVn

V = volume

p = pressure

Data;

P1 =1.0atm

V1 = 1.73L

P2 = 70atm

V2 = ?

P1V1 = P2V2

V2 = P1V1 / P2

V2 = (1.0×1.73)/70

V2 = 0.0247L

The volume of the sample is 0.0247L

Answer:

The answer to your question is given below

Explanation:

8. The equation for the reaction is given below:

Mg3N2 + H2O –> Mg(OH)2 + NH3

Number of reactant atoms before balancing:

Mg = 3

N = 2

H = 2

O = 1

Number of product atoms before balancing:

Mg = 1

N = 1

H = 5

O = 2

Now, let us balanced the equation.

Mg3N2 + H2O –> Mg(OH)2 + NH3

There are 3 atoms of Mg on the left side and 1 atom on the right side. It can be balance by putting 3 in front of Mg(OH)2 as shown below:

Mg3N2 + H2O –> 3Mg(OH)2 + NH3

There are 2 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 2 in front of NH3 as shown below:

Mg3N2 + H2O –> 3Mg(OH)2 + 2NH3

There 2 atoms of H on the left side and a total of 12 atoms on the right side. It can be balance by putting 6 in front of H2O as shown below:

Mg3N2 + 6H2O –> 3Mg(OH)2 + 2NH3

Now the equation is balanced.

Number of reactant atoms after balancing:

Mg = 3

N = 2

H = 12

O = 6

Number of product atoms after balancing:

Mg = 3

N = 2

H = 12

O = 6

9. When methane react with steam, carbon dioxide and hydrogen gas are produced as shown below:

CH4 + H2O –> CO + H2

Now, let us balance the equation. This is illustrated below:

There are a total of 6 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 3 in front of H2 as shown below:

CH4 + H2O –> CO + 3H2

Now the equation is balanced.

Answer:

NH3 is the molecular formula of ammonia

Explanation:

i hope this will help you :)

Answer:

A) It increases when the concentration of reactants increases.

Explanation:

When you increase the concentration, there is more of a substance, and therefore more opportunities for the reactants to collide together with enough energy to create a product.

Answer:

A) It increases when the concentration of reactants increases.

Explanation:

It's just right!!!

Answer:

amoeba is the unicellular organism which can be seen by only microscope but not with our nacked eyes

Answer:

An amoeba often called an amoeboid, is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.

name of parts of ameoba

3 parts – the cytoplasm, plasma membrane and the nucleus. The cytoplasm can be differentiated into 2 layers – the outer ectoplasm and the inner endoplasm. The plasma membrane is a very thin, double-layered membrane composed of protein and lipid molecule

i hope this will help you

Answer:

according to quantum physics newtons 3rd law is in the state of nuclear power things so the answer is c

Explanation:

according to quantum physics newtons 3rd law is in the state of nuclear power things so the answer is c

Answer:

THE HEAT EVOLVED FROM THE COMBUSTION OF 1 MOLE OF GLUCOSE IS - 2819.7 KJ/MOL OR -2.82 * 10^3 KJ/MOL OF HEAT.

Explanation:

Write out the variables given:

Mass of glucose = 3 g

Heat capacity of bomb calorimeter = 2.21 kJ /°C

Mass of water = 1.2 kg

Specific Heat capacity of water = 4.184 kJ/kg °C

Change in temperature = ( 25.50 °C - 19.0 °C ) = 6.5 °C

To calculate the heat evolved from the combustion of 1 mole of glucose, we do the following:

Equation for the reaction:

C6H1206 (s) + 6 02 (g)--------> 6 CO2 (g) + 6 H20 (l)

Calculate the total heat capacity involved in the system:

Heat capacity (Ctotal) = Heat capacity of the bomb calorimeter + heat capacity of water

Ctotal = 2.21 kJ/°C  + (1.2 * 4.184 kJ/kg°C)

Ctotal = 7.2308 kJ°C

Next is to calculate the heat absoorbed by the calorimeter and water

Heat = Heat capacity (Ctotal) * change in temperature

Heat = 7.23 kJ/°C * 6.5 °C

Heat = 46.995 kJ

Hence, the amount of heat evolved when 3g of glucose was involved is 46.995 kJ

Since 1 mole of glucose reacts with 6 moles of oxygen to produce 6 moles of carbon dioxide and water respectively, then the amount of heat needed for the combustion of 1 mole of glucose is:

1 mole of glucose = (12 *6 + 1 * 12+ 16 *6) = 180 g/mol

From 3 g of glucose producing 46.995 kJ of heat

180 g of glucose will produce (180 * 46.995 / 3) kJ of heat

= 2819.7 kJ/mol of heat.

In conclusion, from the combustion of 1 mole of glucose, -2819.7 kJ/ mol of heat is evolved, since the heat was evolved or liberated.

Answer:

Q = mass x sph x temp change

temp change = Q/(mass x sph)

Temp change =57/(22 x .903)

Temp Change = 2.97 ∘C

Temp change 3.0 ∘C

or

We can use the heat equation,

Q = mcΔT

Where Q is the amount of energy transferred (J), m is the mass of the substance (g), c is the specific heat (J g⁻¹ °C⁻¹) and ΔT is the temperature difference (°C).

The given data

 Q = 52 J

 m = 28.4 g

  c = 0.903 J g⁻¹ °C⁻¹

ΔT = ?

By applying the formula,

 52 J = 28.4 g x 0.903 J g⁻¹ °C⁻¹ x ΔT

   ΔT = 2.03 °C

Hence, the temperature change of aluminium during the heating process is 2.03 °C.

Answer:

B. 1 triple bond and 2 single bonds

Explanation:

C2Cl2  has linear structure.

For its Lewis structure, the C2Cl2 molecule has a total of 22 valence electrons. Each Carbon (C) atom has 4 valence electrons and 7 atoms in each chlorine atoms.

So, after pairing in C2Cl2, Chlorine (Cl) form 2 single bonds, one with each carbon atom andboth the Carbon (C) atoms form one triple bond with each other.

Answer:

The correct answer is 7.1 degree C.

Explanation:

Based on the given information, the initial temperature or To of the block is 23.4 degree C.  

The energy lost or Q from the given wooden block is -759 J.  

The specific heat capacity or c of the wood given is 1.716 J/g°C

The mass of the wooden block given is 27.2 grams.  

There is a need to find the final temperature of the wooden block, for this the formula to be used is,  

Q = m × c × (T-To)

Now by putting the given values in the formula we get,  

-759 = 27.2 × 1.716 (T - 23.4)

T = 7.1 degree C.  

Answer:

ΔG°rxn = 28.4kJ/mol at 600K

Explanation:

Using Hess's law, you can find the ΔH°rxn and S°  subtracting ΔH°f of products - ΔH°f of reactants ×its coefficients. In the same way for S°rxn

For example, for the reaction:

aA + bB → cC:

ΔH°rxn = c×ΔH°fC - (a×ΔH°fA + b×ΔH°fB).

S°rxn = c×S°fC - (a×S°fA + b×S°fB).

For the reaction:

SO₂(g) + Cl₂(g) → SO₂Cl₂(g)

ΔH°rxn = 1×ΔH°f{SO₂Cl₂} - (1×ΔH°fSO₂ + 1×ΔH°fCl₂).

S°rxn = 1×S°f{SO₂Cl₂} - (1×S°fSO₂ + 1×S°fCl₂).

As at 298K:

ΔH°f{SO₂Cl₂} = -364.0kJ/mol

ΔH°f{SO₂} = -296.8kJ/mol

ΔH°f{Cl₂} = 0kJ/mol

ΔH°rxn = 1×{-364.4kJ/mol} - (1×-296.8kJ/mol + 1×0).

ΔH°rxn = -67.2kJ/mol at 298K.

S°f{SO₂Cl₂} = 311.9J/molK

S°f{SO₂} = 248.2J/molK

S°f{Cl₂} = 223.0J/molK

S°rxn = 1×{311.9J/molK} - (1×248.2J/molK + 1×223.0J/molK).

S°rxn = -159.3J/molK = -0.159.3KJ/molK

Using:

ΔG°rxn = ΔH°rxn - S°rxn×T

Assuming ΔH°rxn doesn't change at 600K:

ΔG°rxn = -67.2kJ/mol - -0.159.3J/molK×600K

Answer:

A scientist conducts an experiment to determine the rate of the following reaction: N2(g) + O2(g) ? 2NO(g)

Explanation:

Answer:

A central C is double bonded to an O, and single bonded to 2 H

Explanation:

Methanal, also known as formaldehyde, is a chemical compound used to preserve dead biological specimens for further study. It is called formalin when in a solution and it helps keep specimens in a fresh state by hardening the tissues of the specimen involved.

Formaldehyde is a gaseous compound that has an aldehyde functional group i.e. -CHO and has a chemical formula, H-CHO or CH2O as described in the question that a central C is double bonded to an O, and single bonded to 2 H (see attached image for structural formula).

The chemical for the preservation of biological specimens has consisted of central C with a double-bonded O and two single-bonded hydrogens. Thus, option A is correct.

The biological compound that has been used to preserve biological specimens has been methanal. It has been the simplest aldehyde. The chemical formula of formaldehyde, also known as methanal has been H-CHO.

The structure of formaldehyde has been consisted with single bond between H and C. The central carbon has been associated with a double bond between the C and O, with single-bonded H.

Thus, the chemical for preservation of biological specimen has been consisted of central C with a double-bonded O and two single-bonded hydrogens. Thus, option A is correct.

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Answer:

The oxide is basic, X must be a group two metal

Explanation:

The oxide XO2 must be an inorganic peroxide of a group two element. Inorganic peroxides of group two elements are highly basic because they dissolve in water to yield the corresponding metal hydroxides. These metal hydroxides are strongly basic solutions with a very high pH. Hence X may be Calcium, magnesium, barium, strontium or radium.

Group two metal peroxides include; CaO2, MgO2,BaO2 etc. They all dissolve in water to give corresponding basic solutions. For instance, calcium peroxide reacts with water as follows; CaO2 (s) + 2H2O(l) --------->Ca(OH)2(aq) + H2O2(aq). The production of Ca(OH)2 makes the solution basic. The hydrogen peroxide produced decomposes to water and oxygen.

Answer:

All elements have protons and neutrons.

Explanation:

Sure, some standard norms of elements don't have neutrons present (like hydrogen), but different forms of hydrogen have neutrons. Neutrons can and are present in every element in the Periodic Table of Elements.

Answer:

C, Si, Al

Explanation:

We use periodic trends to help us find the atomic radii. The trend for atomic radii on the Periodic Table of Elements is down and to the left. So whichever elements are furthest to the left and farthest down have the largest atomic radii.