A balloon containing helium gas expands from 230 mL to 860 mL as more helium is added. What was the initial quantity of helium present if the expanded balloon contains 3.8 × 10-4 mol, assuming constant temperature and pressure? Which of the variables are known?

Answer:

[tex]\large \boxed{\text{299.4 g}}[/tex]

Explanation:

We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.

Mᵣ:        44.10                          44.01

              C₃H₈   +   5O₂   ⟶   3CO₂   +   4H₂O

m/g:  100.00

To solve a stoichiometry problem, you must

1. Moles of C₃H₈

[tex]\text{Moles of C$_{3}$H}_{8} = \text{100.00 g C$_{3}$H}_{8} \times \dfrac{\text{1 mol C$_{3}$H}_{8}}{\text{44.10 g C$_{3}$H}_{8}} = \text{2.268 mol C$_{3}$H}_{8}[/tex]

2. Moles of CO₂

The molar ratio is 3 mol CO₂:1 mol C₃H₈

[tex]\text{Moles of CO}_{2} = \text{2.268 mol C$_{3}$H}_{8} \times \dfrac{\text{3 mol CO}_{2}}{\text{1 mol C$_{3}$H}_{8}} = \text{6.803 mol CO}_{2}[/tex]

3. Mass of CO₂

[tex]\text{Mass of CO}_{2} = \text{6.803 mol CO}_{2} \times \dfrac{\text{44.01 g CO}_{2}}{\text{1 mol CO}_{2}} = \textbf{299.4 g CO}_{2}\\\text{The mass of CO$_{2}$ required is $\large \boxed{\textbf{299.4 g}}$}[/tex]

Answer:

Number of moles of propane:

=Mass in grams ÷ Relative molecular Mass

= 100/((12*3) + (1*8))

= 100 ÷ 44

= 2.2727

Mole ratio propane:carbon (IV) oxide = 1:3(from the equation)

Number of moles of CO2 = 3*2.2727 = 6.8181

Mass in grams = Relative molecular Mass * Number of moles

= 44 * 6.8181

= 299.9964 grams

Explanation:

Answer:

Basis and basic​ are two different words.

In English, Basis is used as a noun while basic is used as an adjective. Basis term refers as the base or starting point of any discussion.

For example: Bread is a basic ingredient of cake.

                      On the basis of Mendel's hypothesis.

In chemistry, Basis set is used as a set of functions that represent the electronic wave function in the density-functional theory which forms an  algebraic equations that can be easily implemented on a computer.

While Basic term is used for substances that can accept a hydrogen ion (H+) from another substance and have pH above 7. such as sodium.

So, It is not important that both the terms, basis and basic change their English meaning if used in chemistry, they both can be used with English meaning in chemistry as well. Bases and basic,​ both the terms can be used as either English or Chemistry without affecting the meaning.

Answer:

D. Thermal conduction is blocked by the flip-flops.

Explanation:

Convection is a process of heat transfer which involves fluids( liquid or gas). This however rules convection out of the answer.

Radiation involves heat transfer from the sun to bodies on earth.

Conduction involves heat transfer between two solid bodies. Hot beach sand and flip-flops are solid bodies which validates thermal(heat) conduction.

Answer:

Number of energy levels that the element has.

Explanation:

The period number (n) is the outer energy level that is occupied by electrons. The period number that an element is in, is the number of energy levels that the element has.

Answer:

Solute

Explanation:

Answer: C

Explanation:

A P E X

The VSEPR theory predicts the shape and molecular geometry of the molecule.

Molecular geometry can be defined as a three -dimensional arrangement of atoms which constitute the molecule.It includes parameters like bond length,bond angle and torsional angles.

It influences many properties of molecules like reactivity,polarity color,magnetism .The molecular geometry can be determined by various spectroscopic methods and diffraction methods , some of which are infrared,microwave and Raman spectroscopy.

They provide information about geometry by taking into considerations the vibrational and rotational absorbance of a substance.Neutron and electron diffraction techniques provide information about the distance between nuclei and electron density.

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Answer:

True

Explanation:

Because Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.

Answer:

kinetic energy. (General Physics) the energy of motion of a body, equal to the work it would do if it were brought to rest. The translational kinetic energy depends on motion through space, and for a rigid body of constant mass is equal to the product of half the mass times the square of the speed.

Answer:it is the simplest one

the energy possessed by a body due to its motion is called kinetic energy

K.E.=[tex]\frac{1}{2}[/tex]mv²

Answer: true

Explanation: hope this helpes

Answer:

TRUE

Explanation:

power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines.

Answer:

Acid rain causes corrosion in buildings.

Explanation:

This is true because acid rain over time can eat away at the building.

Answer:

Industrial activity increases the emission of greenhouse gases in the atmosphere, especially carbon dioxide (CO2), and it negatively affects climate by increasing global warming.

Two actions to face the global warming:

1- To substitute the use of fossil fuels by alternative clean energy sources such as, for example, hydroelectric, geothermal, solar and wind energy resources.  

2- The government's policies decided to develop electric cars and to stimulate healthy habits such as walking instead of the use of conventional fossil-fueled transport modes.

Answer:

2.alcohol and carbon dioxide

Explanation:

Fermentation is a metabolic process which is used to produce chemical changes in various organic substances. This process is used in many fields including biochemistry, where it is defined as the "extraction of energy from carbohydrates in the absence of oxygen". The main substances produced from fermentation reaction are alcohol, carbon dioxide and lactic acid.

Answer:

A group of cells working together is defined as a tissue and several tissues working together comprise an organ.

Explanation:

Answer:

may be the first one is a producer

Answer:

C. The electron clouds are negatively charged and repel each other as far apart as possible

Explanation:

This is the basis of VSEPR theory.

The angles between the electron clouds determine the shapes of the molecules.

B. and D. are wrong. All electron pairs are negatively charged.

The electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.

Every atom or molecule consist some kind of geometry or shapes like linier, tetrahedral, square planner, octahedral etc. with some bond length and angles present with them.

The bond pairs in a geometry is made up with positive charge and lone pairs present on the atom in the form of negative charge as they both are opposite in nature and repel or push each other in opposite direction.

Due to this phenomena the structure of the atom gets effected and geometry will change on the basis of lone pair and bond pair repulsion.

Therefore, electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.

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Answer: D. 4,6,4

Explanation:

The valence electron is the electron found in the outermost shell of an atom, and participates in bond formation.

For the following element, the valence electron can be noticed when we write the electronic configuration of each element.

Silicon =  1s2 2s2 2P6 3s2 3p2

Sulphur = 1s2 2s2 2P6 3s2 3p4

Germanium =  1s2 2s2 2P6 3s2 3p6 3d10 4s2 4p2

Answer:

Acid is a compound which dissolves in water to produce hydrogen ions (H+) and described as proton donors.

Answer:

the particles with a negative charge are protons

Answer:

1st answer choice

P4O6 + 2 O2 -> P4O10

Explanation:

You need to cancel out reactants and products that are the same.

P4 cancels out because it appears in both reactants and products

We get 2 O2 in the reactants because 5-3= 2

Thus, answer choice 1 is correct.

Answer:

1) 1.39 grams H2O2

2) 0.933 grams Fe

Explanation:

Step 1: Data given

Volume of oxygen = 0.460 L

STP = 1 atm and 273 K

Step 2: The balanced equation

2H2O2(aq) → 2H2O(l) + O2(g)

Step 3: Calculate the number of moles O2

p*V = n*R*T

⇒with p= the pressure = 1 atm

⇒with V = the volume = 0.460 L

⇒with n = the number of moles = TO BE DETERMINED

⇒with R = the gas constant = 0.08206 L*atm/mol*K

⇒with T = the temperature = 273 K

n = (p*V)/(R*T)

n = (1 * 0.460)/ (0.08206*273)

n = 0.0205 moles moles

Step 4: Calculate moles H2O2

For 2 moles H2O we'll have 2 moles H2O and 1 mol O2

For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2

Step 5: Calculate mass H2O2

Mass H2O2 = moles H2O2 * molar mass H2O2

Mass H2O2 = 0.041 moles * 34.01 g/mol

Mass H2O2 = 1.39 grams

Step 1: Data given

Volume of hydrogen = 0.500 L

STP = 1 atm and 273 K

Step 2: The balanced equation

3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)

Step 3: Calculate the moles of H2

p**V = n*R*T

⇒with p= the pressure = 1 atm

⇒with V = the volume = 0.500 L

⇒with n = the number of moles = TO BE DETERMINED

⇒with R = the gas constant = 0.08206 L*atm/mol*K

⇒with T = the temperature = 273 K

n = (p*V) / '*T)

n = (1 * 0.500) / (0.08206 * 273)

n = 0.0223 moles

Step 4: Calculate moles Fe

For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2

For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe

Step 5: Calculate mass of Fe

Mass Fe = moles Fe * atomic mass Fe

Mass Fe = 0.0167 moles * 55.845 g/mol

Mass Fe = 0.933 grams Fe

1. The mass of the hydrogen peroxide should be 1.39 grams H2O2.

2) The mass of the iron should be 0.933 grams Fe.

Since

Volume of oxygen = 0.460 L

STP = 1 atm and 273 K

Now The balanced equation

2H2O2(aq) → 2H2O(l) + O2(g)

Now the number of moles O2

p*V = n*R*T

Here p= the pressure = 1 atm

V = the volume = 0.460 L

n = the number of moles = ?

R = the gas constant = 0.08206 L*atm/mol*K

T = the temperature = 273 K

Now

n = (p*V)/(R*T)

n = (1 * 0.460)/ (0.08206*273)

n = 0.0205 moles moles

Now  moles H2O2 should be

For 2 moles H2O we'll have 2 moles H2O and 1 mol O2

So,

For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2

Now mass H2O2

Mass H2O2 = moles H2O2 * molar mass H2O2

Mass H2O2 = 0.041 moles * 34.01 g/mol

Mass H2O2 = 1.39 grams

2. The mass of the iron should be

Since

Volume of hydrogen = 0.500 L

STP = 1 atm and 273 K

Now

The balanced equation

3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)

Now the moles of H2

p**V = n*R*T

Here

p= the pressure = 1 atm

V = the volume = 0.500 L

n = the number of moles = ?

R = the gas constant = 0.08206 L*atm/mol*K

T = the temperature = 273 K

So,

n = (p*V) / '*T)

n = (1 * 0.500) / (0.08206 * 273)

n = 0.0223 moles

Now Calculate moles Fe

For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2

So,

For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe

Now the mass of Fe

Mass Fe = moles Fe * atomic mass Fe

Mass Fe = 0.0167 moles * 55.845 g/mol

Mass Fe = 0.933 grams Fe

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Answer:

Sulfur?

Explanation:

Sulfur has 6 valence electrons and does not have luster.

Answer: 204 L

Explanation:

According to ideal gas equation:

[tex]PV=nRT[/tex]

P = pressure of gas = 0.262 atm

V = Volume of gas = ?

n = number of moles = [tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{11.7g}{4g/mol}=2.92[/tex]

R = gas constant =[tex]0.0821Latm/Kmol[/tex]

T =temperature =[tex]-50^0C=(273+(-50))K=223K[/tex]

[tex]V=\frac{nRT}{P}[/tex]

[tex]V=\frac{2.92\times 0.0820 L atm/K mol\times 223K}{0.262atm}=204L[/tex]

Thus volume occupied by 11.7 g of Helium in a balloon is 204L

Answer:

The pressure will increase due ot expnasion of gasses in a closed sealed tube tube .

Explanation:

Answer:

The pressure inside of a sealed tube will increase if the temperature is raised.

Explanation:

When the temperature of the gas inside the sealed tube is raised, the particles within that tube will start to become faster and faster. Because they are going faster they collide with the sides of the tube faster, therefore increasing the pressure inside the sealed tube.

Hope this helps!

Answer:

Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information • Graphs are created from data tables • hope that helps love!

Answer:

2Cl- ⇒ Cl ↓2+ 2e

Explanation: sorry if this is not what you were looking for.

Answer:

152

Explanation:

since it weighs 1.9 grams per [tex]cm^{3}[/tex] we get 80*1.9 which is 152 grams

Answer:

2.67761514 moles

Explanation:

0.075kg equates to 75g.

This means that the car emits 75g of CO per km.

dividing 75g by the molar mass of CO (28.01g/mol) we get 2.67761514 moles