Please answer my question.

The denstiy of the gold bar of mass 3300 g is 18.3 g/cm³.

Density is the ratio of mass and volume.

To calculate the density of the bar gold, we use the formula below.

Formula:

Where:

From the question,

Given:

Susbtitute these values into equation 1

The bar is not a pure gold.

Hence, the denstiy is 18.3 g/cm³.

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18.72 moles of oxygen are needed to combust 3.12 moles of glucose.

Glucose is a type of sugar that can be represented by the chemical formula C6H12O6.

When glucose is burned in the human body, it combines with oxygen to form carbon dioxide (CO2) and water (H2O) as waste products.

The balanced equation for the combustion of glucose is:

C6H12O6 + 6O2 -> 6CO2 + 6H2O

From the equation, we can see that for every 1 mole of glucose, 6 moles of oxygen are needed.

To calculate the number of moles of oxygen needed to combust 3.12 moles of glucose, we can use this relationship;-

3.12 moles of glucose * 6 moles of O2/1 mole of glucose = 18.72 moles of O2

So, 18.72 moles of oxygen are needed to combust 3.12 moles of glucose.

The thermochemical equation of the reaction is CO (g) + 3H₂ (g) ⇒ CH₄ + H₂O. 48 KJ heat will be released during this reaction if 67.2 liters of methane.

A balanced stoichiometric chemical equation that includes the enthalpy change i.e, ΔH is called as thermochemical equation.

At STP,

1 mole of any gas occupies a volume of 22.4 L.

The volume of 67.2 L corresponds to  67.2 / 22.

= 3  moles.

1 mole of CO₂ obtained from 1 mole of methane.

3 moles of CH₄ will be obtained from 3 moles of CO₂.

The molar mass of methane = 16 g/mol.

Then, the mass of 3 moles of methane = 3 × 16

= 48 KJ

Thus,The thermochemical equation of the reaction is CO (g) + 3H₂ (g) ⇒ CH₄ + H₂O. 48 KJ heat will be released during this reaction if 67.2 liters of methane.

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The mass of the HNO3 solution was found to be 0.882 g and the titer of the NaoH solution was 0.016g/cm^3.

what was NaoH ?

The inorganic chemical sodium hydroxide, widely known as lye and caustic soda, has the formula NaOH. It is a white solid ionic compound that contains sodium cations Na+ and hydroxide anions OH.

Sodium hydroxide is a caustic base and alkali that degrades proteins at room temperature and can inflict serious chemical burns. It collects moisture and carbon dioxide from the air and is extremely soluble in water. It creates a succession of NaOHnH2O hydrates. Between 12.3 and 61.8 °C, the monohydrate NaOHH2O crystallises from water solutions. This monohydrate is frequently used in commercially available "sodium hydroxide," and published data may refer to it instead of the anhydrous component.

As one of the most basic hydroxides, sodium hydroxide is commonly employed in conjunction with neutral water.

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Answer: Potassium bromide, KBr

Explanation:

Potassium gives a lilac flame in flame test and Bromide ions produce a cream precipitate when they react with Silver ions to form Silver bromide

The mass of one mole of lead is 207.2 g and that of helium is just 4 g/mol. Therefore, a mole of lead weighs more than a mole of helium.

A mole is a unit of measurement that represents the amount of substance in a sample. One mole of any substance contains the same number of particles, which is known as Avogadro's number (6.022 x 10²³ particles per mole). Mass of one mole of an element is called its atomic mass.

The atomic  mass of lead is 207.2 g/mol, which means that one mole of lead has a mass of 207.2 grams. The atomic mass of helium is 4.0 g/mol, which means that one mole of helium has a mass of 4.0 grams.

Therefore, a mole of lead weighs more than a mole of helium, since the molar mass of lead is much greater than that of helium.

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Below is a list of the temperature change solution.

The source of the temperature change is

Initial Temperature - Final Temperature

Temperature measurements

It is a gauge for determining how hot or chilly a body is.

To quantify temperature variations,

The water and iron's beginning and final temperatures are noted.

To Iron

Iron that has been heated up is submerged in water.

Water is at a lower temperature, so both of the temperatures will change.

These information is saved.

Final temperature minus initial temperature equals temperature change.

a) The difference in temperature for metal is 200 - 100 = 100 0C

Water temperature change = 22.5

Change in temperature for both = 23.3

b) 0.7 for water

Metal 76.6 for iron

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Complete Question -

Put the Metal in the Water and Measure

Temperature Changes (Lead)

Measure the initial temperature of the water to the

nearest 0.1°C. Record in the data table.

Initial temperature of metal =

Initial temperature of water

Final temperature of both = [

27

DONE

26

25

24

23

Intro

Continue

AL

250 ml

=பா-©

200

150

100

1

27

O

°C

°C

Answer: 22.6g H2

Explanation:

You need to set up dimensional analysis starting with 11.2moles of H2O (the same as HOH).

First, you need to balance the equation. When balanced, it is:

2H2(g) + O2(g) --> 2H2O(g)

Starting with moles of H2O, you need to go from moles of H2O to moles of H2. To do so, you need to use the mole ratio that you can figure out from the balanced equation. In this case it will be 2mol H2/2mol H2O.

Then just convert to grams using the molar mass of H2 which is 2.016grams.

11.2 mol H2O x (2 mol H2 / 2 mol H2O) x (2.016g H2 / 1 mol H2) = 22.6g H2

When that equation is set up, all units except for grams of H2 will cancel and you'll be able to multiply across.

Answer: 509.8 g

Explanation:

5 moles Al₂O₃

Al: 2 x 26.98 g = 53.96 g

O: 3 x 16.00 g = 48.00 g

Total grams = 101.96 g

1 mole of Al₂O₃ = 101.96 g

5 mol Al₂O₃ x (101.96 g Al₂O₃/1 mol Al₂O₃) = 509.8 g Al₂O₃

Note that moles of Al₂O₃ cancel and you are left with grams, which is what you want.

Answer:

a. To calculate the standard enthalpy of neutralization of sulphuric acid and sodium hydroxide, we can use the formula:

ΔH_neutralization = q_calorimeter / n_reactant

where q_calorimeter is the heat absorbed or released by the solution and n_reactant is the number of moles of reactant.

First, we need to calculate the heat absorbed or released by the solution using the equation:

q_calorimeter = mcΔT

where m is the mass of the solution, c is the specific heat capacity of the solution and ΔT is the change in temperature.

In this case, the mass of the solution is 50 cm³ + 50 cm³ = 100 cm³. The specific heat capacity of the solution is approximately 4.18 J/g°C. The change in temperature is 6.8°C.

q_calorimeter = (100 cm³) (4.18 J/g°C) (6.8°C) = 28.624 J

Then we need to calculate the number of moles of reactant used. The acid is sulfuric acid and the base is sodium hydroxide.

H2SO4 + 2NaOH -> Na2SO4 + 2H2O

The balanced equation shows that 1 mole of H2SO4 reacts with 2 moles of NaOH.

n_reactant = (50 cm³)(0.50 M) + (50 cm³)(0.10 M) = 2.5 moles

Therefore, the standard enthalpy of neutralization of sulphuric acid and sodium hydroxide is:

ΔH_neutralization = q_calorimeter / n_reactant = (28.624 J) / (2.5 moles) = -11.4496 kJ/mol

b. The value obtained in (a) is less than the expected value because heat exchange occurs between the reaction mixture and the calorimeter, which causes a loss of energy. Additionally, the solution may not have been perfectly insulated and heat may have been lost to the surroundings, also causing a loss of energy. Furthermore, the reaction may not have been performed under standard conditions, such as at a specific temperature or pressure.

2.27x1022 molecules of CH4 contains 2.27x1022 moles of CH4 and 8.9x1022 moles of hydrogen atoms.

Hydrogen atoms are the simplest atoms, consisting of a single proton and electron. They are the smallest and most abundant atoms in the universe, making up about 75% of all matter. Hydrogen atoms are also the most reactive elements, easily combining with other elements to form molecules, such as water. They are an essential part of many biochemical reactions, and are used in fuel cells to generate electricity. Hydrogen atoms are also important in astronomy, as they are a key component of stars and other cosmic bodies. Hydrogen atoms are also a major component of the Earth's atmosphere, making up about 20% of the air we breathe. In summary, hydrogen atoms are a vital part of the universe and are essential to life as we know it.

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For a cylinder containing 7.00 grams of helium and a moveable piston. If the capacity was adjusted from 8 l to 12.7 l, the ultimate quantity of moles inside the cylinder would be 11.110 l.

Describe a cylinder?

The three-dimensional shape of a cylinder is made up of two parallel round base connected by a curved surface. The right cylinder is formed when the circular bases' centres cross each other. Right cylinders have parts that are parallel to the planes that include the bases; otherwise, they are referred to as oblique cylinders.

A round cylinder is what?

The circular cylinder is a cylinder with circular bases that are parallel to one another. Three dimensions are involved.

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As per the balanced reaction, 3 moles or 6 g of hydrogen gas produces 2 moles or 34 g of ammonia. Then, 6.5 g of hydrogen produces 36.8 g of ammonia.

Ammonia is a covalent compound formed from the nitrogen atom and three hydrogen atoms. The process of manufacturing of ammonia is called Haber process.

As per the balanced reaction, 3 moles or 6 g of hydrogen gas produces 2 moles or 34 g of ammonia. Then, 6.5 g of hydrogen produces 36.8 g of ammonia.

The mass of ammonia produced from 6.5 g of hydrogen is calculated as follows:

mass of ammonia   = (6.5 × 34 g) / 6 g = 36.8 g

Therefore, the mass of ammonia produced from 6.5 g of hydrogen gas is 36.8 g.

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The depression in freezing point of water here is 3.33 °C. Then the molality of the solution is 1.79. From number of moles of solute is calculated as 0.0161. Then , the molar mass of the solute is 62.11 g.

The addition of a non-volatile salt into a solvent will decrease the freezing point of the solution than the pure solvent. The change in freezing point is proportional to the molality of the solution.

ΔTf = Kf m

Kf is called molal depression constant.

Kf for water = 1.86 °C Kg/mol

given ΔTf = 3.33 (0 - (-3.33))

then m = ΔTf /Kf =  3.33/ 1.86 °C Kg/mol = 1.79

Now, mass of water= 9 g = 0.009 kg

then number of moles = molality × mass of solvent

n = 0.009 kg × 1.79 = 0.0161.

mass of solute taken = 1 g

then, molar mass = 1/0.0161 = 62.11 g.

Therefore, the molar mass of the solute is 62.11 g.

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Answer:

Here is the order of increasing boiling point and increasing solubility in water for the substances you listed:

-2-Methylpropane < -2-butanol < -2-pentanol < -2-propanol

Explanation:

-2-Methylpropane has the lowest boiling point and is the least soluble in water.

-2-butanol has a higher boiling point than -2-methylpropane, but lower than -2-pentanol and -2-propanol

-2-pentanol has a higher boiling point than -2-butanol and -2-methylpropane, but lower than -2-propanol

-2-propanol has the highest boiling point and is the most soluble in water.

Please note that this is a general trend and there can be variations depending on factors such as pressure, purity of the substance, and temperature.

Magnesium is less reactive than the elements of group 1.

Before we get into the question, it is good that we know what we mean by reactivity in chemistry. When we use the term reactivity, we are trying to look at how two or more substances can be able to combine together.

We know that the reactivity of the metals would depend on the position of the metals in the electrochemical series as well as the position of the metal  in the perioidic table of the elements.

Given that the atoms of the elements that we have in group 1 are more electro positive than magnesium, they are going to be much more reactive than the element magnesium and this is evidence by the reduction potentials of the elements that we can easily see from the standard tables.

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To solve this we must be knowing each and every concept related to environment. Therefore, the correct option is option B among all the given options.

An environment may be simply defined as a system that includes all abiotic and biotic components that have an impact on human life. All flora and animals are considered biotic, or living, elements, whereas water, sunshine, air, temperature, etc. are considered abiotic.

Any good, service, or feature that benefits people and society might be considered one of an environment's resources. They might be anything that fulfills a person's requirements on a daily basis. Amount of oxygen in the water is a biotic factor of an aquarium environment.

Therefore, the correct option is option B.

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Answer: B: Water Temperature

Explanation: k12 test 1.04 Science Life semester 2

The mass in kilograms of 100 pills is equal to 0.0697 kilograms.

In Science, a conversion factor can be defined as a number that is typically used to convert (change) a number in one (1) set of units to another, either by dividing or multiplying.

Generally speaking, an appropriate conversion factor to an equal value must be used when it is necessary to perform any mathematical conversion.

Conversion:

1 pill = 697 milligrams.

100 pills = X milligrams.

Cross-multiplying, we have:

Mass of X in milligrams (mg) = 697 mg × 100 pills

Mass of X in milligrams (mg) = 69700 mg.

Next, we would convert the unit of mass in milligrams (mg) to kilograms (kg) by dividing it with a conversion factor of 1 × 10⁶ as follows;

Mass of X in kilograms (kg) = 69700/(1 × 10⁶)

Mass of X in kilograms (kg) = 0.0697 kilograms.

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To create molecules, atoms combine. Two hydrogen (H) atoms and one oxygen (O) atom make up a water molecule's three atoms. H2O is a common abbreviation for water because of this.

The smallest unit of a material that keeps its content and characteristics is a molecule, which is made up of two or more atoms linked together by chemical bonds. The building blocks of chemistry are molecules.

The phrase "the molecules of life" frequently refers to these four categories of molecules. Proteins, carbohydrates, lipids, and nucleic acids make up the four basic building blocks of life. Every single life on Earth depends on one or more of the four categories. These four molecules are necessary for a cell and an organism to exist.

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Answer:

All abiotic and biotic factors of the zoo are part of the ecosystem.

Explanation:

An ecosystem is composed of all the living and non-living things in a particular area, and how they interact with one another. All the items listed, including rocks, water, trees, grass, monkeys, and birds, are part of the zoo ecosystem as they interact with each other and the environment.

The molality of the sodium ions and the sulfate ions are  44.5 and 10.66 respectively.

How do you calculate molality?

The total number of moles of solute per litre of solution is defined as the molarity of a specific solution. Because, unlike mass, the volume of a system changes with changes in physical circumstances of the system, the molality of a solution is reliant on changes in physical qualities of the system such as pressure and temperature. M, which stands for molarity, represents molarity. The molarity of a solution is one molar when one gramme of solute is dissolved in one litre of solution. As we know, the solvent and solute combine to create a solution, hence the total volume of the solution is measured.

molality of sodium was

=480.57/10.781

=44.5

molality of sulfate was

=28.93/2.712

=10.66

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Answer: There is a law

Explanation: This law says if the thing that you throwing could be more height depend how is its volume of mass

The pressure of a gas is directly proportional to its temperature and inversely proportional to its volume.

PV/T = PV/T

(1.00atm * 3.5 L)/ 273k = (P * 0.50L)/(39.1 + 273k)
Do some simple algebra and you will get
P = 8.0 (Note that there should be 2 sigfigs)

A thermodynamic system's property called enthalpy is the result of adding the internal energy of the system and the product of its pressure and volume.

The change in enthalpy for a chemical reaction, also known as the heat of reaction or delta H, is the amount of heat absorbed or released during the reaction at a constant pressure. To calculate the change in enthalpy for the chlorination of propane, you would need to know the enthalpies of formation for the reactants and products, and use the following equation:

ΔH = ΣΔHf (products) - ΣΔHf (reactants)

Where ΔHf is the enthalpy of formation for a given substance.

Without knowing the specific conditions and reactants, it's not possible to give a exact delta H value for the chlorination of propane. But it's an exothermic process, meaning that heat is released during the reaction. The magnitude of the heat released will depend on the specific reactants and conditions used.

Note that an overview was given as the information is incomplete.

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Answer: 64.7 [tex]*10^2[/tex]

Explanation:

Significant figures are the number of digits in a value that correlate with the accuracy of that value.

First lets solve the equation:

(1.7x10^6)/(2.63x10^2) + 7.33 = ?

(1,700,000)/(263) + 7.33

(6,463.8783) + 7.33 = 6,471.2083

We have to simplify the answer to the correct amount of significant digits.

6,471.2083 -> 64.7 [tex]*10^2[/tex]

Answer:

Explanation:

Since 1 gram of radium decays to 1/2 gram in 1622 years that means the half-life of radium is 1622 years.

So,  6 grams also decay to 3 grams in 1622years

Answer: 2:3

Explanation: The question is phrased annoyingly. NH3 to H2 means we need to keep our numbers correct.

2NH3 -> 2 mol of NH3.

3H2 -> 3 mol H2.

NH3/H2 = NH3 to H2.

2:3.

2 mol NH3

----------------

3 mol H2.

2:3, not 3:2.

Answer:

11000

Explanation:

85.3 has 3 significant figures

21.489 has 5 significant figures

0.0059 has 2 significant figures ( as zeros on the left are not significant)

The answer is always rounded off to the least number of decimal places given in the question. Here the least number is two significant figures.

Therefore;

(85.3 - 21.489)/0.0059

= (63.811)/0.0059

= 10815.42

As we have to round off the answer to two significant figures:

= 11000