my chem test is tomorrow!! please help

My Chem Test Is Tomorrow!! Please Help

Answers

Answer 1

Answer:

The pH of the pure water is not always neutral but actually sometimes it can be slightly acidic but not of the same extent or value as HCl obviously. However ,it is enough to result to a color change in the presence of phenolphthalein.

Explanation:

I will try to be brief and spare the boring details .Basically ,this is caused by the reaction of water and CO2 that is naturally present in the atmosphere to produce a weak acid known as carbonic acid.

~Hope this helps:)


Related Questions

Everything can dissolve in water because water is considered a universal solvent.
Liquid water is cooler than solid salt and sugar, allowing them to dissolve easily.
Salt's ions and sugar's polar bonds are both attracted to the polar water molecules.
Small solutes like salt and sugar can fit in the spaces between large water molecules.
What change would increase the amount of solid solute able to be dissolved in liquid water?

Decreasing rate of stirring
Decreasing surface area
Increasing pressure
Increasing temperature

Answers

Answer:

Increasing the temperature

Explanation:

The rate of solubility depends on a few factors. By increasing the temperature, the kinetic energy of the particles increase, leading to a higher rate of diffusion, dissolving the solid solute quicker.

If 34.9g of water is measured out, how many moles is that?

Answers

Answer:

1.94 moles

Explanation:

because moles =mass/mr

=34.9/18

which gives 1.938 so we round it up to 1.94

mr of H2O is 18

hope this helps :)

1.94 moles of water in 34.9 g of water.

Number of moles:

It is defined as given mass over molar mass.

Molar mass = 18 g/mol

Number of moles  =  Given mass  /  Molar mass

Number of moles = 34.9 g / 18 g/mol

Number of  moles = 1.94 moles

Thus, 1.94 moles of water in 34.9 g of water.

Find more information about Number of moles here:

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Which human organ turns the food we eat into a liquid mixture?

Large intestine
Liver
Pancreas
Stomach

Answers

Answer:

the digestive system

Explanation:

The digestive system is the stomache

it breaks down the food

makes glucine

creates energy

Stomach

Explanation:

When food enters your stomach, it mixes the foods and liquids with digestive juices.

Write a hypothesis using IF-THEN - BECAUSE of statement.
Ahmed is curious about the death of the fishes in the ocean. He knows from his environmental chemistry class that pollutants like heavy metals can cause the rapid death of marine organisms. So, Ahmed did an experiment and obtained water samples. He tested that water contains a high amount of lead and chromium.

Answers

Answer:

The correct hypothesis would be - "if a water body contains a high amount of heavy metals such as chromium and lead then the death of the fishes will increase because lead and chromium affect the aquatic environment and gills of fishes."

Explanation:

Heavy metal like chromium in a high concentration can affect the gills of the fishes, it is seen in fishes that swim at the point of disposal of metals at thewater surface harm their gills. In high concentration, it becomes toxic for the fishes.

Lead also causes a negative impact on the aquatic ecosystem if accumulated in a high amount in the aquatic environment that leads to the death of the fishes.

If 10.0 grams of sodium phosphate are reacted, what mass of barium nitrate is
required?

Answers

Answer: The mass of barium nitrate required is 23.91 g

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]    ......(1)

Given mass of sodium phosphate = 10.0 g

Molar mass of sodium phosphate = 163.94 g/mol

Plugging values in equation 1:

[tex]\text{Moles of sodium phosphate}=\frac{10.0g}{163.94g/mol}=0.061 mol[/tex]

The chemical equation for the reaction of sodium phosphate and barium nitrate follows:

[tex]3Ba(NO_3)_2+2Na_3PO_4\rightarrow Ba_3(PO_4)_2+6NaNO_3[/tex]

By the stoichiometry of the reaction:

If 2 moles of sodium phosphate reacts with 3 moles of barium nitrate

So, 0.061 moles of sodium phosphate will react with = [tex]\frac{3}{2}\times 0.061=0.0915mol[/tex] of barium nitrate

Molar mass of barium nitrate = 261.337 g/mol

Plugging values in equation 1:

[tex]\text{Mass of barium nitrate}=(0.0915mol\times 261.337g/mol)=23.91g[/tex]

Hence, the mass of barium nitrate required is 23.91 g

Explain how the particles of air inside the balloon create pressure

Answers

Inside the balloon, the gas particles collide with the balloon's inner walls. ... As the molecules heat up, they move faster and strike the inside wall of the balloon harder. This increased motion of the gas particles increases the force on an area of the balloon, producing a rise in the pressure.

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How many moles are in 7.36 x 1025 molecules of H2O?

Answers

Answer:

There are 122.1982401 moles of  H2O in [tex]7.36*10^{25}[/tex]  molecules of H2O

Explanation:

We know,

[tex]6.023*10^{23}[/tex]  molecules of H2O contains 1 mole H2O

            1      molecules of H2O contains [tex]\frac{1}{6.023*10^{23}}[/tex]  mole H2O

∴ [tex]7.36*10^{25}[/tex] molecules of H2O contains [tex]\frac{1}{6.023*10^{23}}*(7.36*10^{25})[/tex] moles of H2O

                                                               = 122.1982401 moles of  H2O

∴ There are 122.1982401 moles of  H2O in [tex]7.36*10^{25}[/tex]  molecules of H2O

The pressure of a certain amount of gas in a 1.25 L balloon is 760 torr. What would the pressure of that balloon be if it's volume was increased to 2.15 L?

Answers

Answer:

440 torr

General Formulas and Concepts:

Chemistry

Ideal Gas Law

Boyle's Law: P₁V₁ = P₂V₂

P₁ is pressureV₁ is volumeP₂ is new pressureV₂ is new volume

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right  

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of Equality Explanation:

Step 1: Define

Identify

[Given] V₁ = 1.25 L

[Given] P₁ = 760 torr

[Given] V₂ = 2.15 L

[Solve] P₂

Step 2: Solve for P₂

Substitute in variables [Boyle's Law]:                                                              (760 torr)(1.25 L) = P₂(2.15 L)Multiply:                                                                                                             950 torr · L = P₂(2.15 L)[Division Property of Equality] Divide 2.15 L on both sides:                          441.86 torr = P₂Rewrite:                                                                                                             P₂ = 441.86 torr

Step 3: Check

Follow sig fig rules and round. We are given 2 sig figs as our lowest.

441.86 torr ≈ 440 torr

En un tanque se halla CO₂ a 285K ocupando un volumen de 8 L. En esas condiciones determinamos el volumen que ocupa a 393K, considerando que la presión se mantiene constante

Answers

Answer:

11.0 L

Explanation:

Podemos resolver este problema usando la ley de Charles, que afirma que a presión constante:

T₁V₂=T₂V₁

Donde el subíndice 1 indica las condiciones iniciales y el 2 las finales. En este caso:

T₁ = 285 KV₂ = ?T₂ = 393 KV₁ = 8 L

Introducimos los datos:

285 K * V₂ = 393 K * 8 L

Y calculamos V₂:

V₂ = 11.0 L

90 grams of NaNO3 were added to solution at 10 degrees Celsius. What type of solution was formed?

Answers

Answer:

friend me on here and imma send you the link Explanation:

If 2.18 grams of Br2 react with excess KI, how many grams of KBr are formed? Br2 + 2 K1 - 12 +2 KB

Answers

Answer:

2.18 grams of Br2 reacts to produce 3.25 grams of KBr

Explanation:

The balanced equation is

2 KI + Br2 → 2 KBr + I2

2 moles of KI and 1 mole of Br2 reacts to produce two molecules of KBr

Mass of two moles of KI = 2 * 166 grams

Mass of one mole of Br2 = 159.808 grams

Mass of two moles of KBr = 2* 119 grams

Thus,  159.808 grams of Br2 reacts to produce 2* 119 grams of KBr

2.18 grams of Br2 reacts to produce {(2* 119)/ 159.808} * 2.18 grams of KBr

2.18 grams of Br2 reacts to produce 3.25 grams of KBr

what is the difference between autotrophs and heterotrophs?

Answers

Answer:

Autotrophs have the ability to synthesize their own food from the substances surrounding them. Examples of this are photosynthesis or chemical energy. Heterotrophs cannot synthesize their own food. They have to get their nutrition from other animals or plants.

In shorter terms, autotrophs are plants. Heterotrophs are humans.

Explanation:

Particles diffuse

A. from low concentration to higher concentration
B. from higher concentration to lower concentration
C. at any direction​

Answers

B from higher concentration to lower concentration

[tex]\huge{ \mathrm{  \underline{ Answer} \:  \:  ✓ }}[/tex]

The Correct option is :

[tex] \large \boxed{\mathrm{B.}}[/tex]

The particles diffuse from the region of higher concentration to the region of lower concentration.

for example :

At alveoli -

during Inhalation, oxygen is in higher concentration in our lungs but in lower concentration blood capillaries, so oxygen diffuses into the blood and carbon dioxide which is in higher concentration in blood diffuses out from the blood capillaries.

_____________________________

[tex]\mathrm{ ☠ \: TeeNForeveR \:☠ }[/tex]

You are given a small beaker of solution at room temperature. You add a bit of solute to the solution and it dissolves. The original solution was

Answers

Answer:

Unsaturated

Explanation:

An unsaturated solution contains less solute than it can normally hold at a particular temperature.

This kind of solution can also dissolve more solute.

Hence, when a bit of solute is added to this solution, the solute dissolves indicating that the original solution was unsaturated.

Explain the reason that the atomic emission spectrum of hydrogen contains only four lines.
A)
The hydrogen atoms form a continuous series of quantized energy levels
that transmute at a variety of frequencies.
B)
Hydrogen atoms contain a limited number of quantized energy levels that
emit radiation at a limited number of frequencies.
C)
Many hydrogen atoms accomodate an array of quantized energy levels that
can release energy at a progression of frequencies.
A hydrogen atom consists of a sequence of quantized energy levels that
incorporate radiation only from consecutive frequencies.
D)

Answers

Answer:

Though a hydrogen atom has only one electron, it contains a large number of shells, so when this single electron jumps from one shell to another, a photon is emitted, and the energy difference of the shells causes different wavelengths to be released... hence, mono-electronic hydrogen has many spectral lines.

Explanation:

thank me later

The reason that the atomic emission spectrum of hydrogen contains only four lines is the hydrogen atoms form a continuous series of quantized energy levels that transmute at a variety of frequencies.

What is atomic emission spectrum of hydrogen?

The emission spectrum of hydrogen consist of numerous spectral series, the wavelength is postulated by Rydberg formula.

The reason behind the lines of spectrum is the transition of electron between two energies.

Thus, the correct option is A.

Learn more about atomic emission

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b) determine the number of moles of carbon dioxide
produced.​

Answers

Explanation:

The mass of one mole of a substance, expressed in gms, is equal to the mean molecular mass of the substance. The molecular mass of CO2= 12+2x16= 44 so the mass if a mole of CO2 is approximately 44 grams.

Hope it helps!!!...

Please mark it as brainliest...

is how much a material opposes electric current.
*
insulator
conductor
resistance
short circuit

Answers

Answer:

Resistance

Explanation:

Resistance is the measure of the opposition of current in a circuit.

In which radiation does the mass number decrease by 4 and proton number of the nuclei decrease to form a new element?

Answers

Answer:

Alpha

Alpha decay

When a nucleus emits an alpha particle, these changes happen: the mass number decreases by 4.

it is alpha decay!!!

I need D and E please I know the rest

Answers

Answer:

K2 +Br ->2KBr

K + I ->KI

actually I don't know the e option but I had tried can u pls balance it urself

Answer:

D. KOH + HBr will give KBr + H2O

E. KOH + HI will give KI + H2O

How many Fluorine atoms are needed to accept the electrons of one Ca atom?
1
2
3
4

Answers

2 F atoms

Explanation:

A Ca atom has a valence number of +2, which means that when ionized, it will give up two electrons. In turn, a F atom has a valence number of -1, which means it can only accept 1 electron when ionized. So to accommodate the two electrons from Ca atom, we need 2 F atoms.

A 187.4g sample of C3H5(NO3)3 decomposes to produce carbon dioxide, water, diatomic oxygen, and diatomic nitrogen.

1) Write the balanced chemical equation for the decomposition reaction.
2) How many grams of carbon dioxide are produced?
3) How many grams of water are produced?
4) How many grams of diatomic oxygen are produced?
5) How many grams of diatomic nitrogen are produced?
6) The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Verify the law of conservation of mass for the decomposition of the 187.4 g of C3H5(NO3)3 .

Answers

Answer:

Answer:

Kc = 0.20        

Explanation:

                 N₂O₄     ⇄    2NO₂

moles       5.3mol          2.3mol

Vol               5L                5L

Molarity    5.3/5M        2.3/5M

               = 1.06M     = 0.46M

Kc = [NO₂]²/[N₂O₄] =  (0.46)²/(1.06) = 0.1996 ≅ 0.20

Note:

All credit goes to  drpelezo (Ace) who created and explained the answer.

Have a nice day, and I hope this helps

-kiniwih426

If the half-cell containing 1.00 M Fe(NO3)2(aq) in galvanic cells Y and Z is replaced with a half-cell containing 5.00 M Fe(NO3)2(aq), what will be the effect on the cell voltage of the two galvanic cells

Answers

The details of the galvanic cells are missing so i have attached it.

Answer:

The voltage will increase in cell Y and decrease in cell Z.

Explanation:

Looking at the reaction, in half cell 3, we see that reduction takes place in galvanic cell Y while oxidation takes place in galvanic cell Z.

In galvanic cell Y, aluminum gains electrons which is reduction while in galvanic cell Z, Copper loses electrons which is oxidation.

Now, electricity involves movement of electrons and where there is a loss of electrons, it means a decrease in electricity and when there is a gain in electrons, it means there is an increase in electricity.

Now, in electricity, Voltage is directly proportional to electric power.

Thus, the higher the voltage, the higher the electric power.

Thus, in galvanic cell Y that undergoes gain in electrons, there will be an increase in voltage while in galvanic cell Z that undergoes loss of electrons, there will be a decrease in voltage.

Na2S(aq)+Cd(NO3)2(aq) 2NaNO3(aq)+CdS(s)
Sodium sulfide is the limiting reactant. Select the substances that are found in the test tube after the reaction has ended.
A) Na2S
B) Cd(NO3)2
C) NaNO3
D) CdS

Answers

I dont but maybe its c in my opinion

Help plz!
--------------
Objects that are very dense, such as iron, can decrease their density by spreading their mass out over
A. a larger mass
B. a larger volume
C. a larger density
D. a larger object

Answers

Answer:

hi! I hope your having a awesome day

Explanation:

write the chemical formula of 25 compound​

Answers

C2h40
No cap that’s it

Im confused someone please help me

Answers

answer would be c! hope i can help

Select the ion. HCl H 3O +1 H 2O

Answers

Answer:

[tex]H _{3}O {}^{ + } [/tex]

Hydroxonium ion

(06.06 MC)
A gaseous product has a mass of 2.34 g and occupies a volume of 0.854 L. The
temperature in the laboratory is 302 K, and the air pressure is 1.04 atm. Calculate
the molar mass of the gas. (3 points)
1) 22.4 g/mol
2) 44.0 g/mol
3) 65.3 g/mol
4) 86.9 g/mol

Answers

The molar mass of the gas is 65.3 g/mol

How to determine the mole of the gas Volume (V) = 0.854 L.Temperature (T) = 302 KPressure (P) = 1.04 atmGas constant (R) = 0.0821 atm.L/Kmol Number of mole (n) =?

The number of mole of the gas can be obtained by using the ideal gas equation as illustrated below:

PV = nRT

Divide both side by RT

n = PV / RT

n = (1.04 × 0.854) / (0.0821 × 302)

n = 0.0358 mole

How to determine the molar mass Mass = 2.34 gNumber of mole = 0.0358 mole Molar mass =?

Molar mass = mass / mole

Molar mass = 2.34 / 0.0358

Molar mass of gas = 65.3 g/mol

Learn more about ideal gas equation:

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Answer:

65.3 g/mol

Explanation:

use the ideal gas law with molar mass formula

M = mRT/PV

m= 2.34 g

V = 0.854 L

T = 302k

P = 1.04

R = 0.0821

just plug those in and solve

The body system that transports molecules to and from all cells of the body

Answers

cardiovascular system

Answer:

El sistema cardiovascular tiene como función distribuir los nutrientes y el oxígeno a las células del cuerpo y recoger los desechos metabólicos para después eliminarlos en los riñones a través de la orina, y por el aire exhalado en los pulmones. El sistema cardiovascular comprende el corazón, que actúa como una bomba que mantiene el conjunto en funcionamiento, los vasos sanguíneos (arterias, venas y capilares), que son los conductos que transportan la sangre y, la sangre, que es el líquido fluido que contiene las células producidas por la maduración de las células madre de la médula

How many moles of Chromium(III) nitrate (Cr(NO3)3) are produced when Chromium reacts with 0.85 moles of Lead(IV) nitrate (Pb(NO3)4) to produce chromium(III) nitrate (Cr(NO3)3) and lead? 4 Cr + 3 Pb(NO3)4 → 4 Cr(NO3)3 + 3 Pb

Answers

Answer:

[tex]0.64molCr(NO_3)_3[/tex]

Explanation:

Hello there!

In this case, according to the given chemical equation, it turns out possible for us to realize there is a 4:3 mole ratio of chromium(III) nitrate to lead(IV) nitrate, and therefore, we can calculate the moles of the former by applying the shown below stoichiometry setup:

[tex]0.85molPb(NO_3)_4*\frac{3molCr(NO_3)_3}{4molPb(NO_3)_4} \\\\0.64molCr(NO_3)_3[/tex]

Regards!

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