Which of these is an example of a chemical change?

Answer:

TRUE

Explanation: because it is positively charged and protons are positive ions

Answer:

B. O2 is reduced when it accepts electrons and forms water.

Explanation:

During cellular respiration water is formed when oxygen receives electrons and picks up protons at the conclusion of the electron transport chain. The electron transport chain will stop functioning if there isn't enough oxygen to receive electrons (for example, because a person isn't breathing in enough oxygen), and ATP will no longer be created by chemiosmosis. Cells can't carry out the reactions they need to function if they don't even have enough ATP, and they may perish after a long period of time.

Answer:

Shift it toward the side with lower total mole concentration

Explanation:

The reaction will shift in a direction that is less affected by stress, so that the pressure is reduced. This means that the reaction will change towards where there is fewer gas molecules (the fewer gas molecules, the smaller the pressure).

Answer:

A. Shift it toward the side with lower total mole concentration

Explanation:

Answer:

B. Anyone can make a claim, but a scientific claim is backed by experimental evidence.

<3 Have a nice day!!

Answer:

the awnser is B i got it right

Explanation:

Answer:

the answer is option E they are bronsted lowry acid

Answer:

276g of Br are present

Explanation:

To solve this question we need to find the moles of CaBr2 using its molar mass -CaBr2: 199.89g/mol-. As 1 mole of CaBr2 contains 2 moles of Br we can find the moles of Br and its mass:

Moles CaBr2:

345g * (1mol/199.89g) = 1.7259 moles CaBr2

Moles Br:

1.7259 moles CaBr2 * (2mol Br / 1mol CaBr2) = 3.4519 moles Br

Mass Br -Molar mass: 79.904g/mol-

3.4519 moles Br * (79.904g/mol) = 276g of Br are present

Answer:

When gases in containers are heated, their molecules increase in average speed. This means that they exert a greater force when they collide with the container walls, and also collide with the walls more frequently. The gas is therefore under greater pressure when its temperature is higher.

Answer:

-Being in the service of quality, safety, designing and problem solving.

-It plays an importnat part in our lives too, to measure any surface, object, etc.

Explanation:

Measurement is perhaps one of the most fundamental concepts in science. Without the ability to measure, it would be difficult for scientists to conduct experiments or form theories.

Answer:

0.250L of solution. 0.250 moles of solute.

Explanation:

As you can see in the image, there is a beaker with an amount of solution. 1/2L are 500mL and each line of the beaker represents 100mL. That means the volume of the solution is approximately 250mL = 0.250L

Molarity is an unit of concentration defined as the moles of solute per liter of solution. A solution that is 1.000M contains 1.000 moles of solute per liter of solution.

As the volume of the solution is 0.250L, the moles are:

0.250L * (1.000mol/L) = 0.250 moles of solute

Answer:

c

Explanation:

and that's bc it will not share stay the same

Answer:

NO. 10.

performed experiments

NO. 11.

Inference

Explanation:

No 10.

in order to prove that Mary Mellon was in fact infected by typhoid proper experiments needs to be carried out.

No. 11

inference means an assumption due to the situation.

Answer:

B

Explanation:

4.8×10^-4

10^-4 = 0.0001

4.8×0.0001 = 0.00048

Answer:

i am so sorry. i do not have a answer but i am trying to find questioms i can answer

Answer:

Matter is made up of many elements

Answer:

matter is made of smallest tiniest invisible particles.

Answer:

reaction

Explanation:

A reaction is defined as a process where the chemical transformation takes place from one form to some other form. Here, two different chemical substances are reacted together to form some other completely different product.

A hydrogenation process is a chemical process where between the molecular hydrogen and some another element or a compound. This process is usually carried out in the presence of catalyst mainly nickel, platinum or palladium.

Thus, in hydrogenation of a double bond, the catalyst is used to speed up the reaction. The first step in this process is adsorption process, the second step is the diffusion process, the third step is the reaction process and the last step is the desorption process.

Answer:

0.067M H3PO4

Explanation:

H3PO4 reacts with NaOH as follows:

H3PO4 + 3NaOH → 3H2O + Na3PO4

Where 1 mole of H3PO4 reacts with 3 moles of NaOH

To solve trhis question we need to find the moles of NaOH required. With the chemical equation we can find the moles of H3PO4 and its concentration as follows:

Moles NaOH:

50.0mL = 0.0500L * (0.20moles /L) = 0.0100 moles NaOH

Moles H3PO4:

0.0100 moles NaOH * (1mol H3PO4 / 3mol NaOH) = 0.00333 moles H3PO4

Concentration:

0.00333 moles H3PO4 / 0.0500L = 0.067M H3PO4

Answer:

False

Explanation:

it has both magnitude and direction and unit

Answer: The mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.

Explanation:

Given: Mass of solution = 140 g

Mass percent = 12%

Formula used to calculate grams of solute are as follows.

[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}[/tex]

Substitute the values into above formula as follows.

[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}\\= \frac{140 g \times 12 percent}{100 percent}\\= 16.8 g\\= 17 g[/tex]

Thus, we can conclude that the mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.

Considering the definition of percentage by mass, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.  

The Percentage Composition is a measure of the amount of mass that an element occupies in a compound and indicates the percentage by mass of each element that is part of a compound.

This is, the percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.

In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.

The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:

[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]

In this case, you know:

Replacing:

[tex]12=\frac{mass of solute}{140 grams}x100[/tex]

Solving:

mass of solute= [tex]\frac{12 x 140 grams}{100}[/tex]

mass of solute= 16.8 grams ≅ 17 grams

Finally, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.

Learn more about percentage by mass:

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Answer:

-Aerospace Industry.

-Transport Industry.

-Computer Industry.

-Telecommunication industry.

-Agriculture industry.

-Construction Industry.

-Education Industry.

-Pharmaceutical Industry.

-Food Industry

-Health Care Industry

-Hospitality Industry

-Entertainment Industry

Answer: If a gas is pumped from a smaller container to a container that is twice the size, and its pressure is kept the same, then temperature of the gas increases twice.

Explanation:

Charles law states that at constant pressure, the volume of a gas is directly proportional to the temperature.

That is, [tex]V \propto T[/tex].

So, when a gas is pumped from a smaller container to a container that is twice the size shows that volume is increasing by 2 times and its pressure is kept the same.

Therefore,

[tex]2V \propto 2T[/tex]

This means that the temperature of the gas will also become twice its initial temperature.

Thus, we can conclude that if a gas is pumped from a smaller container to a container that is twice the size, and its pressure is kept the same, then temperature of the gas increases twice.

Answer:

There is 9.6 grams of CO2 produced

Explanation:

Step 1: Data given

Mass of methane = 5.50 grams

Molar mass of methane = 16.04 g/mol

Mass of oxygen = 13.9 grams

Molar mass of oxygen = 32.0 g/mol

Step 2: The reaction

CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

Step 3: Calculate number of moles

Moles = mass / molar mass

Moles methane = 5.50 grams / 16.04 g/mol

Moles methane = 0.343 moles

Moles oxygen = 13.9 grams / 32.0 g/mol

Moles oxygen = 0.434 moles

For 1 mol CH4 we need 2 moles O2 to produce 1 mol CO2 and 2 moles H2O

O2 is the limiting reactant. It will completely react (0.434 moles).

There will react 0.434/2 = 0.217 moles CH4

There will remain 0.343-0.217 = 0.126 moles CH4

There will be produced 0.434 moles of H2O and

0.434/2 =0.217 moles of CO2

Step 4: Calculate mass of products

Mass = moles * molar mass

Mass CO2 = 0.217 moles ¨44.01 g/mol

Mass CO2 = 9.6 grams

Mass H2O = 0.434 moles * 18.02

Mass H2O = 7.8 grams

Answer:

i think its C polymer hope it helps

Answer: The mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Explanation:

Given: Volume = 450 L

Temperature = 450 K

Pressure = 300 atm

The reaction equation is as follows.

[tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]

Here, 1 mole of nitrogen reacts to give 2 moles of ammonia.

From the given data, moles of nitrogen are calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into the above formula as follows.

[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{300 atm \times 450 L}{0.0821 L atm/mol K \times 450 K}\\= \frac{135000}{36.945}\\= 3654.08 mol[/tex]

For 3654.08 moles of nitrogen, the moles of ammonia produced is as follows.

[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]

Therefore, mass of ammonia (molar mass = 17.03 g/mol) is calculated as follows.

[tex]Moles = \frac{mass}{molarmass}\\7308.16 mol = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]

Thus, we can conclude that the mass of ammonia is 124457.96 g which can be produced from reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Voltaic cells convert chemical energy to electrical energy by means of an oxidation-reduction reaction while Electrolytic cells convert electrical energy to chemical energy, so they are the opposite of voltaic cells,in an electrolytic cell, the cathode is negatively charged and the anode is positively charged

Answer:

ELECTROLYTIC CELL

An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.

EXAMPLE

Nelsons cell and Downs cell

VOLTAIC CELL OR GALVANIC CELL

The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.

EXAMPLE

Daniel cell

Explanation:

Answer:

2.8 L

Explanation:

From the question given above, the following data were obtained:

Number of mole (n) = 0.109 mole

Pressure (P) = 0.98 atm

Temperature (T) = 307 K

Gas constant (R) = 0.0821 atm.L/Kmol

Volume (V) =?

The volume of the helium gas can be obtained by using the ideal gas equation as follow:

PV = nRT

0.98 × V = 0.109 × 0.0821 × 307

0.98 × V = 2.7473123

Divide both side by 0.98

V = 2.7473123 / 0.98

V = 2.8 L

Thus, the volume of the helium gas is 2.8 L.

B. A circle.

The center void shape that generates the most thrust in a solid fuel rocket is a circle.

What is Fuel?

Fuel is a substance that is used to produce heat or energy through combustion or other chemical reactions. It can be in the form of a solid, liquid, or gas and is typically used to power engines, generators, or heating systems. Examples of fuels include gasoline, diesel, natural gas, coal, wood, and propane. The choice of fuel depends on factors such as availability, cost, energy content, and environmental impact.

This is because a circular shape allows for the most efficient burning of the fuel, with the flame front moving evenly in all directions. Other shapes, such as a heart, triangle, or tree with branches, can cause uneven burning and may result in less thrust.

Learn more about Fuel from the given link

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Answer:

Explanation:

D.
tree with branches