Select the correct answer.
Given the law of conservation of energy, what happens when a 200°C iron bar is placed in thermal contact with a 30°C block of wood?
A
Energy leaves the iron bar and enters the wood until the temperatures are equal.
B. Energy leaves the wood and enters the iron bar until the temperatures are equal.
C. All the energy from the iron bar is transferred to the wood.
D. All the energy from the wood is transferred to the iron bar.

Answer: 401.4g

Explanation:

The mass can be calculated by using the following mathematical expression for Moles ,which is:

Moles = Mass / Molar Mass

From the question given, Moles = 1.72, Molar mass of BaSO4 = 233.38g/mol, Mass =?

Making 'Mass' the subject of formula, we get:

Mass = Molar mass x Moles

= 233.38 x 1.72 = 401.4g

In the water cycle, the stage following evaporation is condensation. This process involves water transforming from a gas back into a liquid form in the atmosphere, eventually leading to precipitation.

In the water cycle, the stage that occurs after evaporation is condensation. After water evaporates from the earth's surface, it rises into the atmosphere where cooling temperatures cause it to change from a gas (steam) back into a liquid form, creating clouds.

This is the process of condensation. It's important to note that the water cycle is a continual process, and after condensation, the cycle usually moves on to precipitation, where the condensed water falls back to the earth as rain, sleet, or snow.

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Answer:

1. Option(1) 3

2. Option (2) 1/2

Explanation:

1. We'll begin by obtaining the molar mass of H3PO4. This is illustrated below:

Molar Mass of H3PO4 = (3x1) + 31 + (16x4) = 3 + 31 + 64 = 98g/mol

Mass of H in H3PO4 = 3x1 = 3g

The percentage by mass of H in H3PO4 given by:

Mass of H in H3PO4/Molar Mass of H3PO4 x 100

=> 3/98 x 100

=> 3

2. Atoms present in H3PO4 are given below:

H = 3 atoms

P = 1 atom

O = 4 atoms

Total = 8 atoms

The fraction of oxygen atom in H3PO4 is given by:

=> Atom of O/total atoms

=> 4/8

=> 1/2

Answer:

Boyle's Law

Explanation:

It's Boyle's law because, for a fixed mass of a perfect gas remaining at a fixed temperature ,pressure and volume are inversely correspondent . Boyle's law is a gas law, that states that  pressure and volume of a gas has an inverse relationship . So, if the volume of the gas increases then,the pressure will decrease and vice versa , when temperature is held constant.

Answer:

1025.08

Explanation:

Answer:

1.025e+6 joules

Explanation:

Answer:

combination reaction

Explanation:

i'm not sure i just searched it on the internet

Answer:

Combination reaction

Explanation:

When sodium reacts with chlorine

It is known to be combination reaction because they will combine to give a specific compound

That is,Na+Cl=NaCl

And the bond formed between them is ionic bond

The volume of a gas is dependent on:

1. Pressure

2. Temperature

3. Amount of gas.

Answer:

2000

Explanation:

it is verified by scientists

3440 kJ is the energy that is required to vaporize 2 kg of aluminum. The elemental source of energy upon earth is said to be the sun.

On earth, energy comes in a variety of ways. The elemental source of energy upon earth is said to be the sun. Energy is seen as a quantifiable property in physics that may be transferred form an item to carry out work. Thus, we might characterise energy as the capacity to engage in any sort of physical action. So, to put it simply, we may describe energy as:

The capacity to perform work is energy. Energy "can neither be created neither destroyed but must instead be converted forms one form to another," according to the rules of conservation of energy. The SI unit for energy is called a joule.

Q = m× Lvapor

    =m×293.4 kJ/mol

    =3440 kJ

Therefore, 3440 kJ is the energy that is required to vaporize 2 kg of aluminum.

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Answer:

520.8 mL

Explanation:

We can solve this problem by using Boyle's Law, which states that:

"For a fixed mass of an ideal gas kept at constant temperature, the pressure of the gas is inversely proportional to its volume"

Mathematically:

[tex]p\propto \frac{1}{V}[/tex]

where

p is the pressure

V is the volume

We can rewrite the equation as

[tex]p_1 V_1 = p_2 V_2[/tex]

where here:

[tex]p_1=12.5 psi[/tex] is the initial pressure of the gas

[tex]V_1=750 mL[/tex] is the initial volume

[tex]p_2=18 psi[/tex] is the final pressure

And solving for V2, we find the final volume of the gas:

[tex]V_2=\frac{p_1 V_1}{p_2}=\frac{(12.5)(750)}{18}=520.8 mL[/tex]

Answer:

Write 2 behind the NaCl so it becomes 2NaCl and 2 behind the NaF so it becomes 2NaF. The others take 1 each

Explanation:

The coefficients of the given balanced chemical equation are 2, 1, 2, 1.

A chemical equation can be defined as the representation of a reaction in terms of symbols of the reactants and products. A chemical equation has of reactants contributing to the reaction, formed products.

The equation which contains the number of atoms of substances that is equal on either side of the equation is known as a balanced chemical equation.

The law of conservation of mass has to be followed by a balanced chemical equation. By obeying this law, the total mass of reactants in the chemical reaction should be equal to the total mass of the products in a balanced chemical equation.

The given equation of the reaction of sodium chloride and fluorine is:

[tex]NaCl + F_2 \longrightarrow NaF + Cl_2[/tex]

The balanced chemical equation for the above reaction NaCl ad F₂ is:

[tex]2NaCl + F_2 \longrightarrow 2NaF + Cl_2[/tex]

Therefore the coefficients to balance the given equation are 2, 1, 2, 1.

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Answer:

Prokaryotic are unicellular organisms that lack organelles or other internal membrane-bound structures. Therefore, they do not have a nucleus, but, instead, generally have a single chromosome: a piece of circular, double-stranded DNA located in an area of the cell called the nucleotide.

Explanation:

Answer:

second

convection current

first

lithosphere

Explanation:

xoxo

Demi

Explanation:

This calculator will find the missing variable in the physics equation for force (F = M * a), when two of the variables are known.

Force is measured in newtons (N)

Force = mass × acceleration

Mass is in kilograms (kg) and acceleration in meters per second squared (m/s2).

Answer:

Q = 25.6 j

Explanation:

Given data:

Energy needed= ?

Mass of lead = 10.0 g

Initial temperature = 30 °C

Final temperature = 50°C

Cp = 0.128 j/g.°C

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 50°C - 30°C

ΔT = 20°C

Now we will put the values in formula.

Q = 10 g × 0.128 j/g.°C × 20°C

Q = 25.6 j

Answer:

True!

Explanation:

Answer: 0.37 m/s

Explanation:

Given that:

Velocity of object = ?

Mass of object = 17.6 kg

kinetic energy of object = 1.19 J

Since kinetic energy is the energy possessed by a moving object, and it depends on the mass of the object and its velocity, apply the formula

K.E = 1/2 x mass x velocity^2

1.19J = 1/2 x 17.6kg x velocity^2

1.19J = 8.8kg x velocity^2

velocity^2 = 1.19J / 8.8kg

velocity^2 = 0.135

To get the value of velocity, find the square root of 0.135

velocity = √0.135

Velocity = 0.367 m/s (Rounded to the nearest hundredth as 0.37m/s)

Thus, the velocity is 0.37 m/s

Answer:

its manganese

Explanation:

Manganese is in the middle of the period has the highest number of oxidation states because all other elements have at least two different oxidation states

Answer: hey its me btw the answer is The number of electrons the element needs to lose or gain to have a full valence shell

Explanation:

Answer : The negative value indicate about the reaction is exothermic and heat is released.

Explanation :

Enthalpy of a reaction (ΔH): It is defined as the energy change that takes place during the chemical processes. It is represented as, ΔH.

If the heat is absorbed during the chemical process then the enthalpy of reaction is positive.

If the heat is released during the chemical process then the enthalpy of reaction is negative.

That means,

When the value of enthalpy of reaction is negative then the heat is released and the reaction will be exothermic reaction.

When the value of enthalpy of reaction is positive then the heat is absorbed and the reaction will be endothermic reaction.

Final answer:

A negative ∆H in calorimetry signifies an exothermic reaction where heat is released by the system to the surroundings.

Explanation:

A negative ∆H in a calorimetry investigation indicates that the reaction is exothermic, meaning heat is released by the system to the surroundings.

For example, if the enthalpy change is negative in the combustion of methane, it signifies that heat is being given off by the system.

In calorimetry, negative ∆H values represent energy being transferred from the system to its surroundings in exothermic reactions.

Answer:

ΔH₁₂ = -867.2 Kj

Explanation:

Find enthalpy for 3H₂ + O₃ => 3H₂O given ...

2H₂ + O₂ => 2H₂O      ΔH₁ = -483.6 Kj

        3O₂ => 2O₃        ΔH₂ = + 284.6 Kj

_____________________________

3(2H₂ + O₂ => 2H₂O) => 6H₂ + 3O₂ => 6H₂O       (multiply by 3 to cancel O₂)

6H₂ + 3O₂ => 6H₂O        ΔH₁ = 3(-483.6 Kj) = -1450.6Kj

          2O₃ => 3O₂           ΔH₂ = -284.6Kj              (reverse rxn to cancel O₂)

_______________________________

6H₂ + 2O₃ => 6H₂O         ΔH₁₂ = -1735.2 Kj       (Net Reaction - not reduced)

________________________________

divide by 2 => target equation (Net Reaction - reduced)

3H₂ + O₃ => 3H₂O            ΔH₁₂ = (-1735.2/2) Kj = -867.2 Kj    

Answer:

-1300

Explanation:

The percentage of water in the hydrated lithium nitrate is calculated by subtracting the mass of the dehydrated compound from the initial mass of the hydrated compound. The result is the mass of water, which is then divided by the initial mass of the hydrated compound and multiplied by 100 to give the percentage of water.

A chemist started with a hydrated lithium nitrate which weighed 170 grams. After heating it and driving off the water of hydration, the mass of the sample reduced to 95.3 grams. This mass reduction is due to the loss of water molecules.

The chemist found that the mass of water lost is 170 grams − 95.3 grams = 74.7 grams. Therefore, the percentage of water in the hydrate can be calculated by dividing the mass of the water lost by the initial mass of the hydrate and then multiplying by 100%.

Using this method, the percentage of water in the hydrated lithium nitrate can be calculated as: (74.7 grams/170 grams)*100% = 43.94%. Therefore, approximately 44% of the mass of the hydrated lithium nitrate is water.

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The mass of carbon dioxide gas occupying a volume of 81.3 L at 204 kPa and 95 °C is calculated using the ideal gas law and converting the pressure and temperature to compatible units, followed by converting moles to mass using the molar mass of CO2.

To determine the mass of carbon dioxide gas that occupies a given volume under specific conditions of pressure and temperature, we can use the ideal gas law. The ideal gas law is represented by the equation PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

Firstly, we need to convert the temperature from Celsius to Kelvin by adding 273.15 to the Celsius temperature:
T(K) = 95 °C + 273.15 = 368.15 K

The pressure needs to be converted from kPa to atm because the standard value for the gas constant R is usually given in units of L atm/mol K. The conversion factor is 1 atm = 101.325 kPa, so:
P(atm) = 204 kPa / 101.325 kPa/atm = 2.012 atm

Using the ideal gas law, we can solve for the number of moles:
n = PV / RT = (2.012 atm)(81.3 L) / (0.082057 L atm/mol K)(368.15 K)

After calculating n, we then convert moles to mass using the molar mass of CO2, which is 44.01 g/mol. The final mass, in grams, will be the product of the number of moles and the molar mass.

Answer:

Endergonic reactions

Explanation:

The terms endergonic and exergonic describe reactions in terms of the energy transfer. Because ender = in, exo = out, we can tell that endergonic reactions need energy put in, and exergonic don't need energy put in, they release energy!

Answer:

34.8 L of hydrogen gas

Explanation:

Now we have to use the ideal gas equation;

PV= nRT

P= pressure of the gas= 3.22atm

V= volume of the gas = ?????

T= temperature of the gas = 45°C +273= 318K

n= number of moles =4.3 moles

R= universal gas constant= 0.082atm Lmol-1K-1

Making V the subject of the formula

V= nRT/P

V= 4.3×0.082×318/3.22

V= 34.8 L

Answer:

34.82 L

Explanation:

Step 1:

Data obtained from the question:

Number of mole (n) = 4.3 mole

Temperature (T) = 45°C = 45°C +273 = 318K

Pressure (P) = 3.22 atm

Volume (V) =?

Step 2:

Determination of the volume hydrogen gas.

With the application of the ideal gas equation, the volume of Hydrogen gas can be obtained as follow:

Note that the gas constant (R) = 0.082atm.L/Kmol

PV = nRT

3.22 x V = 4.3 x 0.082 x 318

Divide both side by 3.22

V = (4.3 x 0.082 x 318) /3.22

V = 34.82 L

Therefore the volume occupied by the hydrogen gas is 34.82 L

The statement of kb is "[C5H5NH+][OH-]/[C5H5N]"

The base dissociation constant is defined as Kb. In water, the base dissociation constant is a measurement of how efficiently a base dissociates into its component ions.

The hydroxide ion is formed when weak bases react with water, as stated in the general equation below, where B is the parent base and BH+ is its conjugate acid:

B(aq) + H2O(l) ⇌ BH+ (aq) + OH−(aq)

The base dissociation constant (Kb), also known as the base ionisation constant, is the equilibrium constant for this reaction:

Kb = [BH+][OH−]/[B]

From the given equation, base dissociation constant comes out to be,

Kb = [C5H5NH+][OH-]/[C5H5N]

Hence the correct answer is Kb = [C5H5NH+][OH-]/[C5H5N]

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Final answer:

In Chemistry, significant figures represent precision in measurements. The number of significant figures varies for each measurement based on the rules of counting significant figures, considering zeros as either placekeepers or significant values.

Explanation:

The subject of this question is Chemistry, particularly focusing on significant figures which are crucial for representing precision in measurements. Let's determine the number of significant figures in each given measurement using the rules for counting significant figures:

0.0908 has three significant figures (leading zeros are not significant).

340.02 has five significant figures (zeros between non-zero digits are significant).

5420 has three significant figures, assuming the last zero is not significant unless otherwise stated (if in scientific notation, it would clarify).

12.90 has four significant figures (trailing zeros in a decimal are significant).

3.09 x 10^8 has three significant figures (all digits in the coefficient are significant).

0.79 has two significant figures (leading zeros are not significant).

0.02050 has four significant figures (trailing zeros in a decimal number are significant).

0.009 has one significant figure (leading zeros are not significant).

4709 has four significant figures (all non-zero digits are significant).

Answer:

The answer is 3rd option.

Explanation:

Lipid is a liquid form of fat

Protein is not a sugar or starch solution.

Carbohydates is a large and complex molecules in a form of sugar.

The pOH of the solution is 8.

What is pOH?

pOH is a measure of the hydroxide ion concentration in a solution, reflecting its alkalinity. It is calculated as the negative logarithm of the hydroxide ion concentration. The pOH scale complements the pH scale, which measures the hydrogen ion concentration, and together they provide a comprehensive view of a solution's acid-base balance.

We know that;

pOH = - log[OH-]

pOH = -log[9.5 *[tex]10^{-9[/tex]]

pOH = 8

a, proton following identifies an element

The number of protons identifies an element. Therefore, option A is correct.

The atomic number is used to identify an element, and it is the number of protons in an element's nuclei. Every element has a distinct number of protons, and thus an atomic number.

Electron configuration, atomic size, ionization energy, electron affinity, and electronegativity are atomic properties that are critical to element behavior.

The atomic number is the number of protons in the nucleus of an atom. The number of protons defines the identity of an element.

The number of protons in an element is the only way to identify it; the number of neutrons and electrons can vary without changing the element's identity.

Thus, The number of protons identifies an element, option A is correct.

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