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Physical Changes Versus Chemical Changes: Mastery Test
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Select the correct answer.
The metal wire in an incandescent lightbulb glows when the light is switched on and stops glowing when it is switched off. This simple process is
which kind of a change?
ОА a physical change
B. a chemical change
ca nuclear change
OD. an lonic change

Answers

Answer 1
B. a chemical change

Related Questions

What volume of oxygen gas at 20°C and 0.919 atm is
consumed in the production of 5.00 g of iron(III) oxide from
metallic iron?
4Fe(s) + 302(g) → 2Fe2O3 (9)
LO2​

Answers

Answer:

Volume of oxygen gas is 78.47L

Explanation:

Data;

Temperature (T) = 20°C = (20 + 273.15)K = 293.15K

Pressure (P) = 0.919atm

Mass (m) = 5g

Volume (v) = ?

Equation of reaction;

4Fe + 3O₂ → 2Fe₂O₃

From the equation of reaction, the number of moles of oxygen is 3.

To find the volume of oxygen produced, we'll have to use ideal gas equation

PV = nRT

P = pressure

V = volume

n = number of moles

R = ideal gas constant = 0.082J/mol.K

T = temperature of the ideal gas

PV = nRT

V = nRT/ P

V = (3 × 0.082 × 293.15) / 0.919

V = 72.1149 / 0.919

V = 78.47L

Volume of the gas is 78.47L

The metabolic oxidation of glucose, C6H12O6, in our bodies produces CO2, which is expelled from our lungs as a gas.
C6H12O6(aq) + 6 O2(g) → 6 CO2(g) + 6 H2O(l)

Calculate the volume of dry CO2 produced at body temperature (37°C) and 0.960 atm when 24.5 g of glucose is consumed in this reaction.

Answers

Answer:

[tex]\large \boxed{\text{21.6 L}}[/tex]

Explanation:

We must do the conversions

mass of C₆H₁₂O₆ ⟶ moles of C₆H₁₂O₆ ⟶ moles of CO₂ ⟶ volume of CO₂

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

Mᵣ:        180.16

         C₆H₁₂O₆ + 6O₂ ⟶ 6CO₂ + 6H₂O

m/g:      24.5

(a) Moles of C₆H₁₂O₆

[tex]\text{Moles of C$_{6}$H$_{12}$O}_{6} = \text{24.5 g C$_{6}$H$_{12}$O}_{6}\times \dfrac{\text{1 mol C$_{6}$H$_{12}$O}_{6}}{\text{180.16 g C$_{6}$H$_{12}$O}_{6}}\\\\= \text{0.1360 mol C$_{6}$H$_{12}$O}_{6}[/tex]

(b) Moles of CO₂

[tex]\text{Moles of CO}_{2} =\text{0.1360 mol C$_{6}$H$_{12}$O}_{6} \times \dfrac{\text{6 mol CO}_{2}}{\text{1 mol C$_{6}$H$_{12}$O}_{6}} = \text{0.8159 mol CO}_{2}[/tex]

(c) Volume of CO₂

We can use the Ideal Gas Law.

pV = nRT

Data:

p = 0.960 atm

n = 0.8159 mol

T = 37  °C

(i) Convert the temperature to kelvins

T = (37 + 273.15) K= 310.15 K

(ii) Calculate the volume

[tex]\begin{array}{rcl}pV &=& nRT\\\text{0.960 atm} \times V & = & \text{0.8159 mol} \times \text{0.082 06 L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times \text{310.15 K}\\0.960V & = & \text{20.77 L}\\V & = & \textbf{21.6 L} \\\end{array}\\\text{The volume of carbon dioxide is $\large \boxed{\textbf{21.6 L}}$}[/tex]

A radioactive isotope has a half life of 25 minutes. How many half lives have occurred after 175 minutes?
5
6
7
8
Will give Brainliest

Answers

Answer:

7

Explanation:

A child has a balloon in his house in the air conditioning. He goes outside with the balloon on a hot day. What happens to the temperature of the gas and volume of the balloon?

Answers

Answer:

There would be an increase in temperature and corresponding increase in the volume of the balloon

Explanation:

Charles law is been here

Charles law  states that the volume of a given mass of gas  is directly proportional to the temperature in Kelvin, provided that the pressure on the gas is kept constant. Mathematically Charles law can be represented thus;

V∝ T

Where V is the volume of the gas and;

T is the temperature.

Relating Charles Law to the question

The child moved outside from the room, constant atmospheric pressure is maintained.The temperature of the room is lower than the temperature outside.

From Charles law postulation, there would be an increase in volume because of the increased temperature, since our pressure is same.

How many senses does the human body have?
O A. 3
B. 5

Answers

Answer:

B

Explanation:

sight, hearing, smell, taste and touch

Answer:

Most easiest answer..

There are 5 senses in human body.☺️

Which of the following did Antoine Lavoisier correctly characterize as an element? light silicone dioxide mercury

Answers

Answer: mercury

Explanation: I looked up the answer to your question.

Answer:

Mercury

Explanation:

I did this question and I got it right.

Which is the molar mass of Calcium?

Answers

Answer:

40.078 u

Explanation:

what happens when light is not spread out

Answers

Answer:

Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets.Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets

Explanation:

Answer the questions using the drop-down menus.
Which is the independent variable in this experiment?
Which is the dependent variable in this experiment?
Which is a controlled variable in this experiment?

Answers

In the experiment to measure the heat absorbed by a material placed in

the Sun, we have;

The independent variable is either the angle of insulation or the type of materialThe dependent variable is the temperature of the materialThe controlled variable is the type of material when the angle of insulation is the independent variable and vice versa

What differentiates the given experimental variables?

The possible experiment is with regards to the factors that influence energy from the Sun

The factors investigated are;

The type of material and the angle of lighting (insulation) affects the absorption of heat

The independent variable is the variable that is the cause of the effect

measured in the experiment.

It is the variable that the researcher has control over or controls and

varies during the experiment to produce the measured effect.

In the above experiment, the independent variable are either ;

The angle of insulation or the type of material respectively

The dependent variable is the variable that is under test or that is being measured.

In the above experiment the dependent variable is the temperature of the material which can be measured

The controlled variable is the variable that remains the same or is held

constant during the experiment and can be used as reference to

compare the dependent variable.

In the experiment, the controlled variable are either;

The type of material when the angle of insulation is the independent variable or vice versa

Learn more about independent and dependent variables here:

https://brainly.com/question/3764906

Answer:

angle of light

temperature of material

type of material

Explanation:

E d g e 22 !

Write the full symbol for the isotope of oxygen having 8 neutrons.​

Answers

Answer:

Isotopes are forms of a chemical element that have the same atomic number but differ in mass. 16O → 8 protons + 8 neutrons; a “light” oxygen); The relative amounts are expressed as either 18O/16O or δ 18O Oxygen - 18 (aka 18O → 8 protons + 10 neutrons; a “heavy” oxygen).

Leon made a study chart about human-induced changes to
the environment.
Which headings best complete the chart?
Environmental Changes Caused by Humans
X: Habitat Destruction
Y: Pollution
Y
Results from
introducing harmful
substances into the
Results from natural areas
being cleared and replaced
by human development
© X: Long-Term Changes
Y: Short-Term Changes
X: Short-Term Changes
Y: Long-Term Changes
0 X: Pollution
Y: Habitat Destruction
environment
Example: deforestation
Example: oil spill​

Answers

The question was not well arranged above. It has been arranged in the answer below.

Question:

Leon made a study chart about human-induced changes to the environment.

Environmental Changes Caused by Humans

X Y

Results from introducing harmful substances into the environment

Example: oil spill

Results from natural areas being cleared and replaced by human development

Example: deforestation

Which headings best complete the chart?

X: Habitat Destruction

Y: Pollution

X: Long-Term Changes

Y: Short-Term Changes

X: Short-Term Changes

Y: Long-Term Changes

X: Pollution

Y: Habitat Destruction

Answer:

X: Pollution

Y: Habitat Destruction

Explanation:

From the above question, Leon gave us two variables, X and Y.

The human induced changes were divided into two.

1. Results from introducing harmful substances into the environment

Introducing harmful substances into the environment is also called pollution. And we can represent this as X which is the first variable.

2. Results from natural areas being cleared and replaced by human development.

This description given in number two above whereby land areas are been cleared and replaced by human development has a negative effects on the environment because the vegetation which includes the trees are been cut down and living organisms(animals) will go extinct gradually. This act affect the balance of the ecosystem and it can be referred to as the destruction of the habitat of living organisms

Therefore, the correct headings best complete the chart is :

X: Pollution

Y: Habitat Destruction

Answer:

what the top person said

Explanation:

What is an example of a polyatomic ion

Answers

Answer: The hydroxide cation (OH -) and the phosphate cation (PO 4 3-) are both polyatomic ions.

Explanation:

Answer:

OH - and PO 4 3- are both polyatomic ions

Which answer gives both a positive impact and a negative impact associated with the effects of nitrogen- and phosphorus-enhanced fertilizers?

A- increased algal blooms and damage to drinking water

B- increased plant growth and damage to drinking water

C- increase in denitrifying bacteria and increase in plant growth

D- increase in a limiting resource and increase in denitrifying bacteria

Answers

Answer:

The answer is B

Explanation:

Answer:

Which answer gives both a positive impact and a negative impact associated with the effects of nitrogen- and phosphorus-enhanced fertilizers?

1. increased algal blooms and damage to drinking water

Right Answer 2. increased plant growth and damage to drinking water

3. increase in denitrifying bacteria and increase in plant growth

4. increase in a limiting resource and increase in denitrifying bacteria

Explanation:

A 0.050L solution of Ba(OH)2 is neutralized by 0.072L of a 0.55 M HNO3 solution. What is the concentration of the Ba(OH)2 solution?

Answers

Answer:

0.396M

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

2HNO3 + Ba(OH)2 —> Ba(NO3)2 + 2H2O

From the balanced equation above,

The mole ratio of the acid (nA) = 2

The mole ratio of the base (nB) = 1

Step 2:

Data obtained from the question. This include the following:

Volume of base (Vb) = 0.05L

Concentration of base (Cb) =..?

Volume of acid (Va) = 0.072L

Concentration of acid = 0.55 M

Step 3:

Determination of the concentration of the base, Ba(OH)2.

The concentration of the base, Ba(OH)2 can be obtained as follow:

Cava /CbVb = nA/nB

0.55 x 0.072 / Cb x 0.05 = 2/1

Cross multiply to express in linear form

Cb x 0.05 x 2 = 0.55 x 0.072

Divide both side by 0.05 x 2

Cb = (0.55 x 0.072) / (0.05 x 2)

Cb = 0.396M

Therefore, the concentration of the base, Ba(OH)2 is 0.396M

how many number of electrons are in aluminium and nitrogen in their free state?​

Answers

Answer:

MRCORRECT has answered the question

Explanation:

13 electrons

So... for the element of ALUMINUM, you already know that the atomic number tells you the number of electrons. That means there are 13 electrons in a aluminum atom. you can see there are two electrons in shell one, eight in shell two, and three in shell three.

7 electrons

So... for the element of NITROGEN, you already know that the atomic number tells you the number of electrons. That means there are 7 electrons in a nitrogen atom. Looking at the picture, you can see there are two electrons in shell one and five in shell two.

what is the compound of scI2

Answers

Answer:

sulfur dichloride

Explanation:

SCl2 is the chemical formula for sulfur dichloride. This compound is made of only two elements, so it is a binary compound.

The element hydrogen has the highest specific heat of all elements. At room temperature, hydrogen's specific heat is 14.30 J/g •°C. If the temperature of a 340.0 g sample of hydrogen is to be raised by 30°C, how much energy will have to be added to the hydrogen?

Answers

Answer:

THE ENERGY NEEDED TO BE ADDED TO RAISE THE TEMPERATURE BY 30°C IS 145, 860 J

Explanation:

The energy needed can be calculated by using the heat formula, which is;

Heat = m c ΔT

m = mass of the hydrogen =  340 g

c = specific heat capacity of hydrogen at room temperature = 14.30 J/g°C

ΔT = change in temperature = 30°C

Heat =?

So therefore,

Heat = 340 * 14.30 * 30

Heat = 145860 J

The energy needed to be added to the hydrogen to bring the mass of 340 g to an increased temperature of 30°C is 145, 860 J or 145.86kJ

What happens when kmno4 is heated

Answers

Answer:

kmno4 is heated => k2mno4 + mno2 + o2

Hope this helps!

:)

Which of these conclusions is correct about P and Q in the diagram?

P represents the land and Q represents the ocean.
P represents the ocean and Q represents the land.
P represents the land and Q represents the atmosphere.
P represents the atmosphere and Q represents the ocean.

Answers

P represents the atmosphere and Q represents the ocean.

Answer:

P represents the atmosphere and Q represents the ocean.

Explanation:

What does the questions “how much?” and “how many?” have in common?

Answers

They both ask for an amount of something

The Sun is a constant supply of energy to Earth.
A. True
B. False

Answers

True.
The sun gives the earth thermal energy, which warmth the planet and effects the weather and the seasons. Also the sun is the beginning of the food chain, because it allows for plants to grow.
We also get our energy either directly or in directly from the sun, either from our food that we eat, or through things like the burning of fossil fuels, which was once plant-matter millions of years ago.

Whats the answer to 7/2 × 1/5?​

Answers

The answer to the problem is 7/10

Answer:7/10

Explanation:multiply top and bottom

1. Calculate the molarity of 35g of calcium chloride (CaCl2) that is dissolved in 850ml of water. (Calculate moles first)

a. 0.27M
b. 0.38M
c. 0.32M
d. 0.80M

2. Calculate the molarity of 90g of copper sulfate (CuSO4) when dissolved in 5 L of water.

a. 0.112M
b. 2.8M
c. 0.56M
d. 0.50M

3. What is the molarity of NaOH if 0.70 moles are dissolved in 250 ml of water?

a. 175,000M
b. 2.8M
c. 0.175M
d. 4M

4. How many moles of Lithium oxide (Li20) are in 2 L of solution with a molarity of 2.0M?

a. 1 mole
b. 2 moles
c. 0.2 moles
d. 4 moles

5. How many moles of NaCl are in 7.5 L of 0.5M?

a. 3.75 moles
b. 15 moles
c. 0.066 moles
d. 2.5 moles​

Answers

Answer:

yo I got same question do u know it

If a body was lying on their back when they died, and was moved to their front after 12 hours, where would one see the skin discoloration from pooling blood?

Answers

Answer:the parts of the body which is nearest to  the ground ie thier back will show discoloration

Explanation:

If the body remains at a position for long hours, the parts of the body which is nearest to  the ground can develop a skin discoloration as a result of pooling of blood in the tissues and this is called livor mortis, which tends to be permanent from 8Hours upwards.

What are three examples of acid-base reactions in cooking

Answers

Answer:

Lemon juice baking soda and vinegar

Explanation:

Ideal Stoichiometry

Barium oxide has a replacement reaction with lithium. Calculate the mass of Barium oxide needed to react with 34.67 g of lithium.

*equation needed and thorough explanation please*

A- 340.5
B- 383.0
C- 455.0
D- 256.8​

Answers

Answer:

the answer is 383.0

hope it is helpful

How many times more acidic is a pH of 2 than a PH of 7?

Answers

Answer: 10 times more

Explanation:

ILL GIVE YOU BRAINLIST * have to get it right * !!! Although individual body systems can perform specific functions, they depend on one another and work together for the good of the entire organism.
Which of the following provides the best evidence that the digestive system and the muscular system work together to carry out their functions?

Answers

I think it might be A muscles help move nutrients through the body to the stomach

Analysis: The limiting reactant(s) appeared to be
because

Answers

there is nothing with which it can react

Explanation:

The limiting reactant(s) prevents a reaction from continuing because there is none left.

Why do limiting reactants occur?

Identification of the limiting reactant makes it possible to calculate the theoretical yield of a reaction. The reason there is a limiting reactant is that elements and compounds react according to the mole ratio between them in a balanced chemical equation.

How do you get the limiting reactant?

The reactant that is consumed first and limits the amount of product(s) that can be obtained is the limiting reactant. To identify the limiting reactant, calculate the number of moles of each reactant present and compare this ratio to the mole ratio of the reactants in the balanced chemical equation.

Learn more about Limiting Reactant(s) here

https://brainly.com/question/14225536

#SPJ2

Calculate the molar mass of ammonium chloride

Answers

Answer:

53.491 g/mol

Explanation:

Create the chemical compound and find each individual element's molar mass. Lastly, add them up.

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