pls help as soon I will give brainlist

Pls Help As Soon I Will Give Brainlist
Pls Help As Soon I Will Give Brainlist
Pls Help As Soon I Will Give Brainlist

Answers

Answer 1
Presence of water and oxygen

You could coat the iron with paint to prevent water coming in contact with it.

Answer 2

Answer:

1) Conditions necessary for rusting are:

a) Presence of atmospheric oxygen or air

b)Presence of water or moisture

2) For protecting the iron gate, we can paint it because the paint will coat it and protect it from atmospheric oxygen and water.

3) Magnesium, Carbon and Oxygen (MgCO₃)


Related Questions

50cm3 of sodium hydroxide solution was titrated against a solution of sulfuric acid. The concentration of the sodium hydroxide solution was 20g/dm3. Work out the concentration of the acid in grams per litre if it took 25cm3 of acid to completely neutralise the alkali. The relative molecular mass of sulfuric acid is 98.

Answers

Answer:

49 g/L is the concentration of the acid

Explanation:

Firstly, we proceed to write the equation of reaction.

2NaOH + H2SO4 ——-> Na2SO4 + 2H2O

We can see that 1 mole of the base reacted with two moles of the acid.

kindly note that dm^3 is same as liter

Firstly, we need to get the concentration of the reacted sulphuric acid in g/L

we use the simple titration equation below;

CaVa/CbVb = Na/Nb

From the question;

Ca = ?

Va = 25 cm^3

Cb = 20 g/L

we convert this to concentration in mol/L

Mathematically, that is concentration in g/L divided by molar mass in g/mole

molar mass of NaOH = 40 g/mol

so we have; 20g/L / 40 = 0.5 mol/L

Vb = 50 cm^3

Na = 1

Nb = 2

Where C represents concentrations, V volumes and N , number of moles

Now, substitute the values;

Ca * 25/0.5 * 50 = 1/2

25Ca/25 = 0.5

So Ca = 0.5 mol/L

Now to get the concentration of H2SO4 in g/L

What we do is to multiply the concentration in mol/L by molar mass in g/mol

That would be 0.5 * 98 = 49 g/L

The concentration of the acid in grams per litre is 49g/L

From the question,

We are to determine concentration of the sodium hydroxide solution.

First, we will write a balanced chemical equation for the reaction.

The balanced chemical equation for the reaction is

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

This means,

2 moles of NaOH is required to completely neutralize 1 mole of H₂SO₄

From the formula

[tex]\frac{C_{A}V_{A} }{C_{B}V_{B} }=\frac{n_{A} }{n_{B} }[/tex]

Where

[tex]C_{A}[/tex] is the concentration of acid

[tex]C_{B}[/tex] is the concentration of base

[tex]V_{A}[/tex] is the volume of acid

[tex]V_{B}[/tex] is the volume of base

[tex]n_{A}[/tex] is the mole ratio of acid

[tex]n_{B}[/tex] is the mole ratio of base

From the question

[tex]V_{A}= 25 \ cm^{3}[/tex]

[tex]C_{B} = 20 \ g/dm^{3}[/tex]

Convert this to mol/dm³

Molar mass of NaOH = 40 g/mol

Using the formula

[tex]Concentration\ in \ mol/dm^{3} =\frac{Concentration\ in \ g/dm^{3}}{Molar\ mass}[/tex]

∴ Concentration of the NaOH in mol/dm³ = [tex]\frac{20}{40}[/tex]

Concentration of the NaOH in mol/dm³ = 0.5 mol/dm³

∴ [tex]C_{B} = 0.5 \ mol/dm^{3}[/tex]

and

[tex]V_{B} = 50 \ cm^{3}[/tex]

From the balanced chemical equation

[tex]n_{A} = 1[/tex]

[tex]n_{B} = 2[/tex]

Putting the parameters into the formula, we get

[tex]\frac{C_{A} \times 25}{0.5 \times 50}= \frac{1}{2}[/tex]

Now, this becomes

[tex]2 \times 25 \times C_{A}=0.5 \times 50 \times 1[/tex]

Then, we get

[tex]50 C_{A} = 25[/tex]

∴ [tex]C_{A} = \frac{25}{50}[/tex]

[tex]C_{A} = 0.5 \ mol/dm^{3} = 0.5 \ mol/L[/tex]

Now, we will determine the concentration in g/L

From the formula,

Concentration in g/L = Concentration in mol/L × Molar mass

From the question,

Molar mass of sulfuric acid = 98

∴ Concentration of the acid in g/L = 0.5 × 98

Concentration of the acid in g/L = 49 g/L

Hence, the concentration of the acid in grams per litre is 49g/L

Learn more here: https://brainly.com/question/25290615

An elements mass number is made up of the number of ____ in the nucleus.

protons and neutrons

electrons and neutrons

protons and electrons

atoms and molecules

Answers

Answer:

The answer is protons and nuetrons

Explanation:

A 2.575 g piece of gold (specific heat = 0.129 J/g°C) at a temperature of 75°C is placed into cold water at 10°C. If the gold loses 10.0 J of energy, what is its final

temperature in the water? Enter your answer to the

nearest whole number of °C.

Answers

Answer:

The final temperature of the mixture is 44.9°C

Explanation:

Mass of the substance (gold) = 2.575g

Specific heat capacity of gold = 0.129J/g°C

Initial temperature (T1) = 75°C

Final temperature (T2) = ?

Energy lost = 10J

Heat energy(Q) = MC∇T

Q = heat energy (in this case lost)

M = mass of the substance

C = specific heat capacity of the substance

∇T = change in temperature of the substance = (T2 - T1)

Q = MC∇T

Q = MC(T2 - T1)

-10 = 2.575 × 0.129 × (T2 - 75) energy is -ve because it was energy lost.

-10 = 0.3321 × (T2 - 75)

-10 = 0.3321T2 - 24.9075

Collect like terms

0.3321T2 = 24.9075 - 10

0.3321T2 = 14.9075

T2 = 14.9075 / 0.3321

T2 = 44.88

T2 = 44.9°C

The final temperature of the mixture is 44.9°C

Level 3- How is tooth decay related to pH?How can it be prevented?

Answers

Answer:

A lower pH of the mouth creates bad bacteria that eventually lead to decay of the tooth.  

It can be prevented by avoiding food that causes acidity.

Explanation:

Tooth decay is caused by the pH level in the mouth dropping below 5.5, meaning it is acidic. It can be prevented by brushing your teeth as toothpaste is an alkali which will neutralise the pH level in your mouth.

Hope this helps

Can someone please help me with this question

Answers

Answer:

the second one I think...

Answer:

The answer is the first one.

Acceleration is the change of velocity

Velocity is another term for speed with direction.

NEED HELP
What is the temperature in kelvin of a gas if it is allowed to expand from 1.50 L to 4.50 L? The initial temperature is 10.0°C and pressure is constant throughout the change. Which equation should you use?

Answers

Answer:

Explanation:

V1/T1 =V2/T2    at constnant pressure

Answer:

c

Explanation:

50 points - I need this really soon! plz help

The pictured compound has which bond?
A.) C = C and C −C
B.) C = C and C −H
C.) C −Cand C −H
D.) C −C, C −H, and C −O

Answers

Answer:

C.

Explanation:

Butane (C4H10) has 3 C-C bonds in the carbon chain and 10 C-H bonds

Butane ([tex]C_4H_10[/tex]) has 3 C-C bonds in the carbon chain and 10 C-H bonds

What is alkane?

Alkanes are saturated hydrocarbons. This means that their carbon atoms are joined to each other by single bonds.

Based on the diagram, butane is considered to be an alkane. It not only contains single covalent bonds, but also has carbon and hydrogen atoms present in its structure.

When comparing both structures to one another, isobutane is a branched chain, while butane is a linear chain.

Learn more about alkane here:

https://brainly.com/question/4260635

#SPJ2

Difference between rapid combustion and spontaneous combustion.

Answers

Answer: The difference between rapid combustion and spontaneous combustion...

Explanation:

Rapid combustion is a form of combustion, otherwise known as a fire, in which large amounts of heat and light energy are released, which often results in a flame.Whereas spontaneous combustion is the ignition of organic matter (e.g. hay or coal) without apparent cause, typically through heat generated internally by rapid oxidation.

The electron dot diagram for a neutral atom of chlorine (atomic number 17) is shown below.

Which of the following symbols represents a chlorine ion with a stable arrangement of eight valence electrons?
A. 35Cl1-
B. 35Cl2-
C. 35Cl1+
D. 35Cl

Answers

Answer:

A. 35Cl1-

Explanation:

Chlorine needs 1 more electron to have full octet thus will take 1 electron and possess a -1 charge.

What would the molecular formula be if lithium and sulfur reacted to form a neutral compound?

Answers

Answer:

Li2S

Explanation:

Since Lithium gives away one electron, I believe it goes to Sulfur.

Hope this helps! :)

Answer:

Li*2S

Explanation:

ed tell chem

the wavelength of a light wave whose frequency 5.0x 10^9 s^-1 is

Answers

Answer:

wavelength = 6 cm .

Explanation:

frequency given = 5 x 10⁹ .

wavelength = velocity of light / frequency

= 3 x 10⁸ / 5 x 10⁹

= .06 m

= 6 cm

where are people mostly exposed to chemicals?

Answers

Answer:

people are mostly exposed to chemicals through their nose, mouth, eyes, and ears

Explanation:

they are the easiest way for anything, bad or good, to enter the body because  people touch their face alot.

This might not answer what you were looking for but the other answer covered it pretty well so I thought I'd give you another angle to the question!

Hope this helps!!

Give some examples of how ultraviolet rays can be used

Answers

Answer:

One of the most common ways of producing UV light is passing an electric current through vaporized mercury or some other gas. This type of lamp is commonly used in tanning booths and for disinfecting surfaces. The lamps are also used in black lights that cause fluorescent paints and dyes to glow.Explanation:

1. Look at yourself in the front of the spoon (the side where the food sits). What do you see?
The you see the image

Answers

Answer:

If you look at yourself in the front of the spoon, you see that the mirror forms an inverted real image.

Explanation:

The word 'concave' means to bend inwards.

A curved mirror is a mirror that has a curved reflecting surface.

The front side of the spoon is just like a concave mirror. If you look at yourself in the front of the spoon, you see that the mirror forms an inverted real image.

Concave mirrors produce real inverted image of an object only if it is placed further away from the mirror than the focal point.

Answer:

It shows me upside down like a ghost. OoooOooh

Explanation:

Boo

In the following reaction, which are the products?

Mg + 2HCl —> H2 + MgCl2

If you could, please explain as well.​

Answers

Answer: H2 + MgCl2

Explanation: As they are on the right side of the equation/ are the products being made as a result of the reaction, they are the products.

WILL MARK BRAINLIEST IF GOOD EXPLANATION...

Ethyl acetate is a sweet-smelling solvent used in varnishes and fingernail polish remover. It is produced industrially by heating acetic acid and ethanol
together in the presence of sulfuric acid, which is added to speed up the
reaction. The ethyl acetate is distilled off as it is formed. The equation for the
process is as follows.

CH3COOH + CH3CH2OH --> CH3COOCH2CH3 + H2O

Determine the percentage yield in the following cases:
a. 68.3 g of ethyl acetate should be produced but only 43.9 g is recovered.
b. 0.0419 mol of ethyl acetate is produced but 0.0722 mol is expected. (Hint:
Percentage yield can also be calculated by dividing the actual yield in moles
by the theoretical yield in moles.)
c. 4.29 mol of ethanol is reacted with excess acetic acid, but only 2.98 mol of
ethyl acetate is produced.
d. A mixture of 0.58 mol ethanol and 0.82 mol acetic acid is reacted and 0.46
mol ethyl acetate is produced. (Hint: What is the limiting reactant?)

Answers

Answer:

a) 64.27%

b) 58%

c) ethanol is the limiting reactant

d) ethanol is the limiting reactant

Explanation:

We have to note that the expected yield is the theoretical yield while the actual mass or amount of product formed is the actual yield.

a) theoretical yield=68.3g

Actual yield= 43.9 g

Percentage yield= 43.9/68.3 ×100

Percentage yield= 64.27%

b) theoretical yield= 0.0722 moles

Actual yield = 0.0419

Percentage yield= 0.0419/0.0722 × 100

Percentage yield= 58%

c) note that the limiting reactant yields the least number of moles of product

Ethanol will be the limiting reactant since it is not present in excess.

d) from the reaction equation;

1 mole of acetic acid produces 1 mole of ethyl acetate

0.58 moles of ethanol produces 0.58 moles of ethyl acetate

1 mole of acetic acid yields 1 mole of ethyl acetate

Hence 0.82 moles of acetic acid yields 0.82 moles of ethyl acetate

Hence ethanol is the limiting reactant.

The diagram shows the setup of an experiment. The observations of the experiment are listed in the table below the diagram. A beaker filled three-fourths with a liquid labeled colorless silver nitrate solution is shown. A small strip is shown inside the beaker. The strip is labeled copper strip. The title of the image is Experimental Setup. Experimental Observations Observation Description 1 Copper strip became thinner 2 Gray particles were deposited on the edge of the strip Which of the following is the correct explanation for one of the given observations? (4 points) Observation 2 is a result of nitrate ions moving into the solution. Observation 2 is a result of silver ions moving into the solution. Observation 1 is a result of copper atoms losing two electrons. Observation 1 is a result of silver atoms losing one electron.

Answers

Answer:

The answer is Observation 1 is a result of copper atoms losing two electrons.

Explanation:

The electrons result in the color change of the copper strip, causing the gray particles to join onto the metal.

Answer:

C

Explanation:

Observation 1 is a result of the copper atoms losing two electrons. It came out as the right answer.

The density was of a solution of sulfuric acid is 1.285g/cm3 and it is 38.08% (by weight) acid. How many millimeters of the acid solution do you need to supply 125 grams of sulfuric acid?

Answers

Answer:

255.5cm³

Explanation:

A solution that is 38.08 % by weight has 38.08g of sulfuric acid per 100g of total solution. Thus, mass of solution you need to obtain 125g is:

125g H₂SO₄ × (100g solution / 38.08g H₂SO₄) = 328.3g of solution

As density of the solution is 1.285g / cm³, the volume of 328.3g is:

328.3g × (1cm³ / 1.285g) = 255.5cm³

Attempt 1 of 1
Which of the following is most likely to have a crystalline structure?
wood
rubber
glass
quartz

Answers

I’m not 100% positive but quartz would make sense

Answer: Quartz

Explanation: I looked it up ;)

Which phrase describes a feature of a Mercator projection? is least commonly used sizes most features to scale presents longitude lines as parallel shows most accurately near the prime meridian

QUICK

Answers

Answer:

  presents longitude lines as parallel

Explanation:

The Mercator projection shows longitude lines as  parallel, hence greatly distorts sizes and distances near the poles. A useful feature is that a course of constant bearing shows as a straight line.

Answer:

C.) presents longitude lines as parallel

Explanation:

Took it on E2020

What is the definition of a scientific theory

A) A method of learning that emphasizes reason as the way to understand the world.
B) A brief statement that summarizes past observations and predicts future ones.
C) A model that explains the underlying reasons for observations and laws.
D) The equivalent of a scientific opinion which others may disagree with.
E) None of these.

Answers

Answer:

The correct answer to the following question will be Option C.

Explanation:

The theory seems to be the context within which findings are explained as well as possible predictions are made. This theoretical perspective discusses the factors behind the results as well as the laws.Theories have been used in scientific knowledge to give wide interpretations to accommodate observed facts in case the root reason is still yet to be found as well as characterized.

So that Option C will be the right answer.

What is the frequency of radiation emitted by a photon of light if the energy released during its transition to ground state is 3.611 × 10-15 joules? (Planck's constant is 6.626 × 10-34 joule seconds)

Answers

Answer:

5.449 x 10¹⁸ Hz

Explanation:

Energy (E) =Frequency (F) x Plancks constant (h)

F= 3.611x10⁻¹⁵J / 6.626 x 10⁻³⁴ Js⁻¹

F =5.449 x10¹⁸ s⁻¹ or 5.449 x 10¹⁸ Hz

The energy from 0.015 moles of octane was used to heat 250 grams of water. The temperature of the water rose from 293.0 K to 371.2 K. What is the enthalpy of combustion of octane? The specific heat capacity of water is 4.18 J/K g.

A. -5448 kJ/mol
B. 1226 kJ/mol
C. -1226 kJ/mol
D. 293.25 kJ/mol

Answers

I would probably go with B but it also might be D

Answer:

A.) -5448 kJ/mol

Explanation:

I got it correct on founders edtell

at what temperature would 2.10moles of N2 gas have a pressure of 1.25atm and fill a 25.0 L tank

Answers

Answer:

[tex]\large \boxed{\text{-92 $^{\circ}$C}}[/tex]

Explanation:

We can use the Ideal Gas Law and solve for T.

pV = nRT

Data  

p = 1.25 atm

V = 25.0 L

n = 2.10 mol

R = 0.082 06 L·atm·K⁻¹mol⁻¹

Calculations

1. Temperature in kelvins

[tex]\begin{array} {rcl}pV & = & nRT\\\text{1.25 atm} \times \text{25.0 L} & = & \rm\text{2.10 mol} \times 0.08206 \text{ L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times T\\31.25&=&0.09847T\text{ K}^{-1}\\T& = &\dfrac{31.25}{\text{0.098 47 K}^{-1}}\\\\& = &\text{181 K}\end{array}[/tex]

2. Temperature in degrees Celsius

[tex]\begin{array} {rcl}T & = & (181 - 273.15) \, ^{\circ}\text{C}\\& = & -92 \, ^{\circ}\text{C}\\\end{array}\\\text{The temperature of the gas is $\large \boxed{\mathbf{-92 \, ^{\circ}}\textbf{C}}$}[/tex]

let's consider the effectiveness of two antacids to illustrate how chemical calculations can be important in daily life. Baking soda NaHCO3, is often used as an antacid. It neutralizes excess hydrochloric acid sereted by stomach. The balanced equation for the reaction is NaHCO3(s)+HCl(aq)=H20(l)+CO2(g). Milk of magnesia, which is an aqueous suspension of magnesium hydroxide, Mg(OH)2(s)+2HCl(aq)=2H20(l)+MgCl2(aq), Which anatacid can consume the most stomach acid, 1.00g of NaHCO3,or 1.00g of Mg (OH)2?

Answers

Answer:

Milk of Magnesia would consume the most stomach acid at almost 3 times the amount as baking soda.

Explanation:

Baking Soda = NaHCO3(s)+HCl(aq)=H20(l)+CO2(g)

NaHCO3 Molar mass of 84.007 g/mol

0.012 Moles of NaHCO3 and since an equal ratio of HCl is required

we therefore neutralize 0.012 Moles of HCl

Milk of magnesia = Mg(OH)2(s)+2HCl(aq)=2H20(l)+MgCl2(aq)

Mg(OH)2(s) Molar mass: 58.3197 g/mol

0.017 Moles of Mg(OH)2 and the ratio is 2:1, so 2 moles for each 1 mole of Mg(OH)2, so we need 0.034 Moles of HCl

Element X is a solid that is brittle, lacks luster,and has six valence electrons. In which group on the Periodic Table would element X be found

Answers

Answer:

Sulfur?

Explanation:

Sulfur has 6 valence electrons and does not have luster.

Which process occurs at each link in a food chain?

Answers

Some Energy is released into the environment as heat

Explanation:

A 500ml bottle contains 2.50 moles of gas. What is the new volume when the number of miles is increased 5.00 moles?

Answers

Answer:

The new volume is 1,000ml

Explanation:

Mathematically, we know that the number of moles per ml(volume) should be constant irrespective of the increase.

Initially, we have a volume of 500 ml and number of moles of 2.5 moles

The ratio of the number of moles to the volume is 2.5/500 = 0.005 mole/ml

Now, this is expected to remain the same even if we have an increment.

let’s call the new volume x

0.005 mol/ml = 5 moles/x ml

x = 5/0.005 = 1,000 ml

In an ecosystem, why can only one species fill an ecological niche?

Answers

Answer:

Explanation:es porque las especies con nichos idénticos tienen las mismas necesidades, lo que significa que competirían exactamente por los mismos recursos.

In which orbitals would the valence electrons for carbon (C) be placed?

Answers

Answer: orbitals supernumerary

Explanation:

Answer:

both S orbital and p orbitals

Explanation:

took the exam got the question right.

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The distance around the edge of a circular pond is 88 m. The radius, inmetres. 19 Suppose that a wave has a period of 0.03 seconds what is its frequency be sure to show the steps for your work The two independent cases are listed below: Case A Case B Year 2 Year 1 Year 2 Year 1 Sales Revenue $11,000 $9,000 $21,000 $18,000 Cost of Goods Sold 6,000 5,500 12,000 11,000 Gross Profit 5,000 3,500 9,000 7,000 Depreciation Expense 1,000 1,000 1,500 1,500 Salaries and Wages Expense 2,500 2,000 5,000 5,000 Net Income 1,500 500 2,500 500 Accounts Receivable 300 400 750 600 Inventory 750 500 730 800 Accounts Payable 800 700 800 850 Salaries and Wages Payable 1,000 1,200 200 250 Show the operating activities section of the statement of cash flows for year 2 using the indirect method. (Amounts to be deducted should be indicated with a minus sign.) Find the exact length of the third side. (Pythagorean Theorem) What is The mass of an electron A couple borrows $200,000 for a mortgage that requires fixed monthly payments over 30 consecutive years. The first monthly payment is due in one month. If the interest rate on the mortgage is 5%, which of the following comes closest to the monthly payment?When would the calculation of the effective annual interest rate be most useful?a. When comparing two investments with different annuity amountsb. When comparing two investments with different par valuesc. When comparing two investments that end at different points in timed. When comparing two investments that compound differently within a yeare. When comparing two investments that have different inherent risk A stone is thrown vertically into the air at an initial velocity of 79 ft/s. On a different planet, the height s (in feet) of the stone above the ground after t seconds is sequals79tminus3t squared and on Earth it is sequals79tminus16t squared. How much higher will the stone travel on the other planet than on Earth? Solve for y: 3y + 6 = -45 A researcher classifies firefighters according to whether their gloves fit well or poorly and by gender. They want to know if there is a difference in the proportion of poorly fitted gloves and gender. At alpha = 0.01, use the chi-square test to determine if there is a difference in the population proportion of glove fitness for the two genders. Observed data Males Females TotalGloves fit poorly 132 20 152Gloves fit well 415 19 434Total 547 39 586Expected data Males Females TotalGloves fit poorlyGloves fit wellTotal Write a short essay comparing and contrasting lyric and narrative poetry. A short-term effect of anorexia might include weight loss.O A. TrueO B. False Which of the steps of the scientific method means to create an explanation of the facts as you see them?a.Observec.Testb.Hypothesized.PredictPlease select the best answer from the choices providedHURRY, PLEASE HELP ME! a student placed a stack of rocks on a ramp. she added clumps of soil rooted with live grass. using a garden hose, she then applied a steady spray of water that soaked into the soil, making it heavier. what does the students experiment model Which inequality is true?5(2)>103(13) Government spending that is required by laws that have been previously passed is called __________ spending. What is the slope-intercept for Y-5 =-3x+2 How many square roots is the area ? Plaintiffs filed a class action lawsuit against investment banks alleging that they inflated prices on more than 300 IPOs, causing IPO investors to overpay for stock, and unlawfully benefited these banks through overcompensation of banking commissions and profits made through quick sales of this stock in their own accounts before prices settled into a more realistic valuation. How would you combat such abuses going forward Fill in the blanks with the correct word or phrase.The process of change in a population over time is called .The process by which organisms that are better adapted to the environment survive and reproduce is called . Please help me with 2 more questions ill give good ratings please!