my chem test is tomorrow!! please help

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:

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.

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

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.

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.

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Answer:

Resistance

Explanation:

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

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.

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.

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Answer:

hi! I hope your having a awesome day

Explanation:

440 torr

Chemistry

Ideal Gas Law

Boyle's Law: P₁V₁ = P₂V₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Equality Properties

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

Step 3: Check

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

441.86 torr ≈ 440 torr

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.

[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 :

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]

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.

Answer:

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

Hydroxonium ion

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

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!!!...

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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.

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!

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

Answer:

11.0 L

Explanation:

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

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

Introducimos los datos:

Y calculamos V₂:

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.

Answer:

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

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

Answer:

Alpha

Alpha decay

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

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

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.

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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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

The molar mass of the gas is 65.3 g/mol

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

Molar mass = mass / mole

Molar mass = 2.34 / 0.0358

Molar mass of gas = 65.3 g/mol

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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