In chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with the more active metals. He placed the following into 4 separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, and (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals, and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water. What is the independent variable?
a) the amount of water
b) the metals strips
c) amount of rust
d) hydrochloric acid

Answers

Answer 1

Answer:

b) the metals strips

Explanation:

In an experimental design, an independent variable is a variable that is changed or manipulated in a series of experiments. An independent variable is not dependent on any other variable in the experiment. The hypothesis for this experiment is stated to be: "If the chemical activity of the metallic wrapper is increased, then less rusting of iron will occur. The independent variable relates to the type of metal wrapping strip, and the dependent variables are the amount of rusting and color of the water.


Related Questions

helpppppp i hate chemistry
I will give brainiest who helps me with the correct answer
I promise

5. Name the compound which contain Strontium, Fluorine, and Oxygen.

Options:

Strontium fluorate
Strontium fluoride
Strontium chlorate
Strontium fluorine

Answers

Answer:

The first option: Strontium Fluorate.

Explanation:

because Fluorine and oxygen combines to make fluorate, Strontium stays the same.

p.s: i need help in geo and there's an exam tomorrow.

I WILL GIVE BRANLIEST What factor is the temperature in an ecosystem? Abiotic or Biotic?

Answers

Abiotic I think

“ temperature is an abiotic factor with an ecosystem abiotic factors are the parts of an ecosystem that are nonliving such as weather and temperature”

Answer:abiotic .

Explanation:

Determine the final temperature of a system, if 120 grams had an initial temperature of 80°C and mixes with 3,000 g of water at an initial temperature of 20°C

Answers

Answer:

The final temperature of the mixture is 22.3°C

Explanation:

Assuming that the 120 g substance at 80°C is water, final temperature of the mixture can be determined using the formula:

Heat lost = Heat gained

Heat = mc∆T where m is mass, c is specific heat capacity of water, and ∆T is the temperature change = Tfinal - Tinitial.

Let the final temperature be T

Heat lost = 120 × c × (T - 80)

Heat gained = 3000 × c × ( T - 20)

Equating the heat lost and heat gained

120 × c × -(T - 80) = 3000 × c × (T - 20)

9600 - 120T = 3000T - 60000

60000 + 9600 = 3000T + 120T

69600 = 3120T

T = 69600/3120

T = 22.3°C

Therefore, the final temperature of the mixture is 22.3°C

what occurs at the cathode of a galvanic cell? (sorry about the picture my back camera is broken)

Answers

Answer:

The reduction half-reaction of a redox reaction

Explanation:

(just took the test)

The reduction of half-reaction of a redox reaction. Hence, option B is correct.

What is an electrolytic cell?

An electrolytic cell converts electrical energy into chemical energy or vice versa.

A galvanic cell is an electrochemical cell in which chemical energy is converted to electrical energy. The chemical reaction which drives a galvanic cell is a redox reaction i.e. a reduction-oxidation process.

A typical galvanic cell is composed of two electrodes immersed in a suitable electrolyte and connected via a salt bridge. One of the electrodes serves as a cathode where reduction or gain of electrons takes place. The other half cell functions as an anode where oxidation or loss of electrons occurs. Batteries and fuel cells are examples of galvanic cells.

Hence, option B is correct.

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A state property X has a value 89.6 units. It undergoes the following changes, first increase by
3.6 units, then increase by another 18.7 units, then decrease by 12.2 units and finally attains a
value of 85.5 units The value for this series of change is A) 14.2 units
B) -4.1 units C) 108.3 units
D) uncertain​

Answers

Answer:

B) -4.1 units

Explanation:

According to this question, a state property X has a value 89.6 units. It undergoes the certain changes as follows:

- first increase by 3.6 units

- then increase by another 18.7 units

- then decrease by 12.2 units

- and finally attains a value of 85.5 units

This can be mathematically represented by 89.6 - {3.6 + 18.7 - 12.2 - x) = 85.5

To get x, we say;

89.6 + 3.6 = 93.2

93.2 + 18.7 = 111.9

111.9 - 12.2 = 99.7

99.7 - 85.5 = 14.2units.

The changes that occured is represented as follows:

= (3.6 + 18.7) - (12.2 + 14.2)

= 22.3 - 26.4

= -4.1 units

Why are flowers brightly colored?

Answers

Answer: In order to help the plants reproduce, flowers that are bright in color are meant to attract birds, bees and other insects. In the genetics of a flower, bright or dull colors are set in

Explanation:

What is the mass of 0.9210 moles of sulfur dioxide gas (SO2)?

Answers

Answer:

58.944 g

Explanation:

From the question given above, the following data were:

Mole of SO2 = 0.9210 mole

Mass of SO2 =?

Next, we shall determine the molar mass of SO2. This can be obtained by adding the molar mass of sulphur and oxygen together as illustrated below:

Molar mass of SO2 = 32 + (2 × 16)

= 32 + 32 = 64 g/mol

Finally, we shall determine the mass of 0.9210 mole of SO2 as follow:

Mole of SO2 = 0.9210 mole

Molar mass of SO2 = 64 g/mol

Mass of SO2 =?

Mole = mass /Molar mass

0.9210 = mass of SO2 / 64

Cross multiply

Mass of SO2 = 0.9210 × 64

Mass of SO2 = 58.944 g

Thus, the mass of SO2 is 58.944 g.

Give a scenario in which a good conductor would come in handy.

Answers

Explanation:

Not sure if ment like an electric type that gives off energy but here is my answer. a good conductor comes off handy in every situation. meaning, without one a machine, or whatever the conductor is being used for could be unstable, or not be able to work perfectly. which would could lead to certain malfunctions. so a good conductor could also give you a better chance of succeeding.

how do i caculate velocity

Answers

Answer:

Velocity Equation in these calculations:

Final velocity (v) of an object equals initial velocity (u) of that object plus acceleration (a) of the object times the elapsed time (t) from u to v.

Explanation:

What evidence always shows that a chemical change has happened?
O A. The total mass of material changes.
O B. A new substance is produced.
C. A solid material dissolves in a liquid.
O D. A liquid changes into a solid.

Answers

Answer:

B. A new substance is produced.

Explanation:

In chemical changes, you will always have a new end product from the reactants that were used within the process.

Please mark as brainliest! <3

Please HELP ME please it would be amazing if you can!!

Answers

Answer:

i think 4

Explanation:

Answer:

i guess number 4

Explanation:

When a 0.4500 g sample of impure potassium chloride was dissolved in water and treated with an excess ofsilver nitrate, 0.8402 g of silver chloride was precipitated. Calculate the percentage KCl in the original sample.

Answers

Answer:

97.78% KCl in the original sample

Explanation:

The % of KCl in the original sample would be as follows:

[tex]97.78[/tex]%

Given that,

Amount of sample of impure Potassium Chloride [tex]= 0.4500 g[/tex]

Amount of Silver Nitrate precipitated [tex]= 0.8402g[/tex]

Now,

Molarity of KCl = [tex]74.5 g/mol[/tex]

Minimum moles required for reaction [tex]= 0.0059 mol[/tex]

Final number of moles  [tex]= 0.0059 mol[/tex]

So,

Concentration = Number of moles * Molarity

[tex]= 0.0059 mol * 0.74.5 g/mol\\= 0.440g[/tex]

Therefore,

% of KCl in the original Sample = Weight of Pure KCl/Weight of Impure KCl

[tex]= 0.440/0.450[/tex] × [tex]100[/tex]

[tex]= 97.78[/tex]%

Thus, [tex]97.78[/tex]% is the correct answer.

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Answers

Answer:

hxtististsy z7tzotz8tsx lhsitzrizrs ypzyztozkt udriztkzto

A cylinder fitted with a piston has 10 dm3
of a gas 27ºC. How can you double the pressure
by varying the temperature only?

Answers

Answer:

go to the website quizlet it will help you!!!!!!!!

Explanation:

Please Help!!!

Which of the following is not a good indication that a chemical change has occurred?
A. The formation of gases
B. A change in color
C. A scratched surface
D. The release heat or light​

Answers

Answer:

C.

Explanation:

A chemist is identifying the elements present in a sample of seawater. What characteristic of an element’s atoms always determines the element’s identity?

Answers

The element is sodium, and it is highly reactive. The atoms of a certain element each contain 11 protons and one valance electron.

What is the best definition of biology?
A. The study of energy and light
B. The study of matter
C. The study of applied science
D. The study of living things

Answers

Answer:

D. The study of living things

Explanation:

prefix "bio-" means life, living things

The scientist philosopher Aristotle is known as the father of biology. The best definition of biology is the study of living things. The correct option is D.

What is biology?

The branch of science which deals with the study of living organisms, their origins, anatomy, morphology, and distribution is known as the biology. Biology is a natural science discipline which studies living things.

The study of living things and their important processes is explained in biology. This field deals with all the physiochemical aspects of life. It is sub divided into other branches like botany, physiology and zoology.

Thus the correct option is D.

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6. All changes in states of matter (freezing, evaporation, condensation, etc.) are
a. physical changes
b. chemical changes

Answers

Pretty sure its Physical Changes

No chemical reaction is happening.

Answer:

Changes of states are physical changes

Explanation:

They are reversible changes that do not involve changes in matter's chemical makeup or chemical properties.

PLEASE MARK BRAINLIEST

Right Now Please <_> I really need it to level up

What type of conspiracy did Apple take part in?

Answers

There is sufficient evidence to show that Apple violated Section 1 of Sherman Act by making publishers raise price of e-books.

Explanation:

Google

if the atomic mass is 14 and the atomic number is 7,how many neutrons do you have?​

Answers

Answer: 7 neutrons

Explanation: Atomic number refers to the number of protons in the nucleus of the atom. Also you can treat atomic mass as how many particles (protons and neutrons) are in the nucleus of the atom. So for this problem:

14 particles - 7 protons = 7 neutrons (and we know all that's left over is neutrons because we subtracted all the protons)

A student wants to develop a model of an organism's cell that lacks chloroplasts. Which statement BEST explains how the lack of chloroplasts affects an organism?Your answer:An organism that lacks chloroplasts would not be able to convert sunlight into chemical energy through photosynthesis.An organism's cells would not be able to reproduce since the chloroplasts contain the genetic material.An organism that lacks chloroplasts would not be able to manufacture all the protein required by its cells

Answers

Recall that the main function of chloroplasts is to convert sunlight to chemical energy, or to carry out photosynthesis.  Plant (and eukaryotic algae) cells contain these organelles, while animal cells do not, and hence, animals cannot carry out photosynthesis.

So, a lack of chloroplasts would mean that an organism would not be able to convert sunlight into chemical energy through photosynthesis.

Plants cells, and specifically the chloroplast organelle, are able to absorb sunlight, and together with CO₂ and water, produce glucose (for the plant to eat) and oxygen (which is released into the atmosphere).  That glucose is further broken down by the plants' mitochondria.  Animals directly consume the glucose to be broken down and converted into energy, hence why we do not have - nor need - chloroplasts in our cells.

Knowledge of the functioning of cells and DNA has led to the creation of new life in laboratories. What is an example of an ethical question this raises?
a) Why are cells and DNA important to study?
b) How do cells create new life?
c) How many cells do humans have?
Is it wrong to change or control life forms?​

Answers

Answer:

Explanation:

It’s D

Answer:

D. Is it wrong to change or control life forms?

Explanation:

edge 2021 :P

Which of the following equations is not balanced? ​

Answers

Explanation:

i think the answer is first and last

first equation only.
last one is balanced!!

A student has a remote control for a television. The student points the
remote at the television and presses a button on the remote labeled
Volume. A small red light flashes on the front of the remote. The student
observes that the sound from the television becomes lower.
Which statement best describes how the remote control communicates
with the television to change the volume of the sound?
a

Od
The remote control sends microwaves toward the television that are absorbed by the front of the television
The remote control sends low-energy infrared radiation to a light detector on the front of the television
The remote control sends radio waves in many directions, which bounce off the walls of the room toward the front of the
television
The remote control sends sound waves in many directions, which bounce off the walls of the room toward a vibration detector on
the front of the television
od

Answers

Answer:

The remote control sends low-energy infrared radiation to a light detector on the front of the television

Explanation:

The signal between a remote control and the TV controls consists of pulses of infrared light, which is invisible to the human eye

State the career function of mechanical engineering​

Answers

Answer:

Mechanical engineers design power producing machines, like electric generators, internal combustion engines, and steam and gas turbines, also power using machines, such as refrigeration and air-conditioning systems. Mechanical engineers design other machines inside buildings, such as elevators and escalators.

Explanation:

If the atomic number of Lithium is 3 and its mass number is 7, how many protons, electrons, and neutrons does a neutral
atom of Li have

Answers

Answer:

Protons = 3

Neutrons = 4

Electrons = 3

Explanation:

For every atom, the atomic number is equal to the number of protons.

In a neutral atom (atom with no charge) the number of protons is equal to the number of electrons.

To calculate neutrons subtract the number of protons (atomic number) from the rounded molar mass:

7 - 3 = 4 neutrons

5)
Experiments with gold foil indicated that atoms
A)
usually have a uniform distribution of positive charges
B)
usually have a uniform distribution of negative charges
C)
contain a positively charged, dense center
D)
contain a negatively charged, dense center

Answers

Answer:

c

Explanation:

I just learned all this in chemistry too lol

got 100 on the test last week so its good

Experiments with gold foil indicated that atoms contain a positively charged, dense center and the correct option is option C.

Experiments with gold foil, known as the Rutherford gold foil experiment, were conducted by Ernest Rutherford in 1911. In this experiment, he bombarded a thin gold foil with alpha particles.

Most of the alpha particles passed through the foil with little deflection, but some of them were deflected at large angles, and a small fraction even bounced back. This observation led Rutherford to conclude that the atom contains a positively charged, dense center called the nucleus, where most of its mass is concentrated. He proposed the nuclear model of the atom, which became a significant advancement in the understanding of atomic structure.

Thus, the ideal selection is option C.

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A brick has a volume of 475 cubic centimeters and a mass of 912 grams. Calculate its
density.
Write your answer to the hundredths place

Answers

Answer:

1.92 g/cm³

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question we have

[tex]density = \frac{912}{475} \\ [/tex]

We have the final answer as

1.92 g/cm³

Hope this helps you

How many moles are equal to 145 g of sodium carbonate?

Answers

More explain??!!?!???

Answer:

There are

0.0642 mol Na

2

CO

3

in

6.80 g

.

Explanation:

The chemical formula of sodium carbonate is

Na

2

CO

3

. The molar mass of sodium carbonate is

105.988439 g/mol

.

What else is produced during the combustion of butane, C4H10?

2C4H10 + 13O2 8________ + 10H2O

Answers

Answer:

CO2

Explanation:

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