The food web above shows how energy moves through a lake environment. If a chemical company were to put a harmful chemical
that kills off all of the phytoplankton, which animal would be immediately affected?
)
A)
bacteria
B)
invertebrates
human
D)
prey fish

1.827 × 10²⁴ molecules H₂S

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Compounds

Atomic Structure

Step 1: Define

103.4 g H₂S (Sulfuric Acid)

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of H - 1.01 g/mol

Molar Mass of S - 32.07 g/mol

Molar Mass of H₂S - 2(1.01) + 32.07 = 34.09 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 4 sig figs.

1.82656 × 10²⁴ molecules H₂S ≈ 1.827 × 10²⁴ molecules H₂S

Answer:

56.04 g

Explanation:

Step 1: Given data

Moles of nitrogen (n): 2 mol

Step 2: Calculate the molar mass of nitrogen (M)

The molar mass of the molecule is the sum of the masses of the molecules that form it.

mN₂ = 2 × mN = 2 × 14.01 g/mol = 28.02 g/mol

Step 3: Calculate the mass corresponding to 2 moles of nitrogen

We will use the following expression.

m = n × M

m = 2 mol × 28.02 g/mol = 56.04 g

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Answer:

The molar mass of carbon

Explanation:

Before the mass (in grams) of two moles of carbon can be determined, the molar mass of the element would be needed.

This is because the number of mole of an element is the ratio of its mass and the molar mass. That is,

number of mole = mass/molar mass

Hence, the mass of elements can be obtained by making it the subject of the formular;

mass = number of mole x molar mass

Therefore, the molar mass of carbon would be needed before the mass of 2 moles of the element can be determined.

Answer:

sodium phosphide

Explanation:

Answer:

D

Explanation:

compound 1 probably ether and compound 3 1-bromo ethane have 2 carbon atoms

The decay product represented by X : Thorium (Th) : ²³⁴₉₀Th

Given

Decay reaction

²³⁸₉₂U ⇒ ⁴₂He + X

Required

The decay product

Solution

Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,  

In a decay reaction, the sum of the mass number and atomic number of the elements in the reactants and products must be the same

So the mass number of the element X = 238 - 4 = 234

Atomic number of the element X = 92 - 2 = 90

If we look at the periodic system, then the element with atomic number 90 is Thorium (Th)

Answer:It is number 4

Explanation:

Answer:

Explanation:

The first process is to draw out the heating curve to have a look at the transition possible which we've shown in the file below.

Now;

To find the energy removed to convert 75g steam → ice then comparing it with 215 kJ.

So conversion of steam at 125 °C → 100 °C

[tex]\Delta H = (75 \ g) (2.0 \ J/g^0C ) (125 - 100)^0 \ C[/tex]

[tex]\Delta H = 3750 \ J[/tex]

[tex]\Delta H = 3.75 \ kJ[/tex]

Since this is lesser than the energy given  (215 kJ), we then have to find the energy removed in the next phase.

For condensation of steam

Find the energy removed to change the steam from 100° C to liquid  at 100° C

[tex]\Delta H_2 = ( \dfrac{75 \ g}{18.02 \ g/mol}) (40.7 \ kJ/mol)[/tex]

[tex]\Delta H_2 =1.690* 10^ 2 \ J[/tex]

[tex]\Delta H_2 =169 \ kJ[/tex]

The total energy that is now removed from the system is:

[tex]\Delta H_1+ \Delta H_2 = (169 + 3.75) \ kJ[/tex]

[tex]\Delta H_1+ \Delta H_2 \simeq 173 \ kJ[/tex] which is still lesser than 215 kJ

To the third step; which is the conversion of water at 100° C → water at 0° C

[tex]\Delta H_3 = ( 75 \ g) (4.2 \ J/g^0 C)(100-0)^0C[/tex]

[tex]\Delta H_3 = 31500 \ J[/tex]

[tex]\Delta H_3 = 31.5 \ kJ[/tex]

Thus;

[tex]\Delta H_1+\Delta H_2+\Delta H_3 = (169 + 3.75 +31.5) \ kJ[/tex]

[tex]\Delta H_1+\Delta H_2+\Delta H_3 =204 \ kJ[/tex]

To the fourth step;

For freezing of water; we need to find the energy removed to change the water at 0° C → ice at 0° C

[tex]\Delta H_4 = (\dfrac{75 \ g}{18.02 \ g/mol})(6.02 \ kJ/mol)[/tex]

[tex]\Delta H_4 = 25.1 \ kJ[/tex]

∴

To change to the solid phase at 0° C; the total energy that is being removed from the steam is  

[tex]\Delta H_1+\Delta H_2+\Delta H_3 +\Delta H_4 =(169 + 3.75 + 31.5 +25.1) \ kJ[/tex]

[tex]\Delta H_1+\Delta H_2+\Delta H_3 +\Delta H_4 =229 \ kJ[/tex]

Here, the calculated total energy is more than the given energy 215 kJ.

This implies that the water is not fully converted to ice when 215 kJ of energy removal occurs, Hence the two phases that exist are liquid and solid.

Answer:

Mass = 19.85 g

Explanation:

Given data:

Volume of chlorine gas = 80.4 L

Temperature = standard = 273.15 K

Pressure = standard = 1 atm

Mass of chlorine = ?

Molar mass of chlorine gas = 70.9 g/mol

Solution:

PV = nRT

R = general gas constant = 0.0821 atm.L/mol.K

By putting values,

1 atm × 80.4 L = n× 0.0821 atm.L/mol.K  × 273.15 K

80.4 atm.L = n× 22.43 atm.L/mol

n = 22.43 atm.L/mol / 80.4 atm.L

n = 0.28 mol

Mass of Cl₂:

Mass = number of moles × molar mass

Mass = 0.28 mol × 70.9 g/mol

Mass = 19.85 g

This question is not complete, the complete question is;

Calculate the final pH of a solution made by the addition of 10 mL of a 0.5 M NaOH solution to 500 mL of a 0.4 M HA originally at pH  = 5.0 ( pKa = 5.0)

Neglect the volume change.

Options:

a) 6.10

b) 5.09

c) 7.00

d) 5.02

Answer:

the final pH of a solution is 5.02

Option d) 5.02 is the Correct Answer

Explanation:

Given the data in the question,

Initially pKa = pH; so ratio is 1:1

thus, 0.4 M acid and base

Now, moles of NaOH = molarity × volume = 0.5 × 10 = 5 mmol = 5 × 10⁻³ mol.

Going into 500 mL ( 0.5 L ) of solution

new molarity will be;

⇒ moles / volume = 5 × 10⁻³ / 0.5 = 0.01 M

ACID reacting with BASE

original concentration of acid = 0.4 - 0.01 = 0.39 M

original concentration of base = 0.4 + 0.01 = 0.41 M

so

pH = 5 + log( base/acid)

= 5 + log ( 0.41/0.39)

= 5 + log ( 1.0512)

= 5 + 0.021

pH = 5.02

Therefore the final pH of a solution is 5.02

Option d) 5.02 is the Correct Answer

Answer:

2000 m

Explanation:

From the question given above, the following data were:

Elevation (m) >>>>>> Temperature (°C)

4000 >>>>>>>>>>>>> –8

3500 >>>>>>>>>>>>> –4

3000 >>>>>>>>>>>>> 0

2500 >>>>>>>>>>>>> 4

Temperature = 8 °C

Elevation =?

A careful observation of the table shows that:

Elevation is reducing with 500 m, while the temperature is increasing with 4 °C.

Next, we shall determine number of increase in the temperature. This can be obtained as follow:

Last Temperature from the table = 4 °C

New temperature = 8 °C

Difference = 8 °C – 4 °C

Number of Increase = difference / 4 °C

Number of Increase = 4 °C / 4 °C

Number of Increase = 1

Thus, the temperature increased just ones from 4 °C to 8 °C

Since the temperature increased just ones from 4 °C to 8 °C, it means the elevation will decrease just ones i.e

Last elevation from the table = 2500 m

Decrease factor = 500 m

New elevation = 2500 – 500

New elevation = 2000 m

Thus, the temperature (i.e 8 °C) was recorded at an elevation of 2000 m

Answer:

See explanation

Explanation:

The nucleophile here is CH3OH. We know that CH3OH is a good nucleophile that promotes SN2 reanction. However, (R)-6-bromo-2,6-dimethylnonane is a tertiary alkyl halide so the reaction proceeds by SN1 mechanism. This means that a racemic mixture is obtained at the end of the reaction because the attack occurs at the stereogenic carbon atom (6R) hence the product is optically inactive.

On the other hand, when (5R)-2-bromo-2,5-dimethylnonane is reacted with CH3OH, an optically active product is obtained because; though a tertiary alkyl halide and reaction occurs by SN1 mechanism, the attack does not occur at the stereogenic carbon atom (5R). Therefore, an optically active product is obtained in this case.

Answer:

Yes this is true

Explanation:

Answer:

i have the same question for chemistry, do you have the answer?

Explanation:

Answer:

[tex]1.214\ g[/tex]

Explanation:

[tex]We\ know\ that,\\No.\ of\ molecules\ of\ Hydrobromic\ acid=9.03*10^{21} HBr\ molecules\\Now,\\We\ know\ that\ Hydrobromic\ acid\ is\ constituted\ by\ 1\ Hydrogen\ molecule\\ and\ 1\ Bromine\ molecule.\\Gram\ Atomic\ Mass\ of\ Bromine \approx 80\ g\\Gram\ Atomic\ Mass\ of\ Hydrogen =1\ g\\Hence,\\The\ Gram\ Molecular\ Mass\ Of\ Hydrobromic\ Acid=1*1+1*80=81\ g\\Avagadro's\ Constant=6.022*10^{23}\ particles[/tex]

[tex]Now,\\We\ know\ that,\\Mass=\frac{No.\ of\ particles}{Avagadro's\ Constant}*GMM\\Here,\\Mass\ of\ 9.03*10^{21} molecules\ of\ HBr= \frac{9.03*10^{21}}{6.022*10^{23}}*81 \approx 1.214\ g[/tex]

Answer:

- the central atom is usually the atom with the lowest subscript in the molecular formula and the atom that can form the most bonds. If all of the atoms usually form the same number of bonds, the least electronegative atom is usually the central atom.

- molecular shape (the shape that a single molecule has) is important in determining how the molecule interacts and reacts with other molecules. Molecular shape also influences the boiling point and melting point of molecules. If all molecules were linear then life as we know it would not exist.

Answer:

Zero with the subscripts, +2 without them.

Explanation:

Hello!

In this case, since we consider that two silicon are bonded with four oxygen atoms to form silicon oxide according to the following chemical equation:

[tex]Si^{4+}+O^{2-}\rightarrow Si_2O_4[/tex]

It is also possible to realize it can be simplified to obtain:

[tex]SiO_2[/tex]

Which means that the total charge with the subscripts is zero, and without the subscripts +2 (+4-2).

Best regards!

The ionic formula for the ionic crystal is Fe₃O₂

Ionic crystals are solid, crystalline ionic substances that are made up of ions linked together in a regular lattice structure by electrostatic attraction.

From the given structure; the key element shows that:

Therefore, from the diagram, the correct formula of the ionic crystal by considering the lone pairs and valence electrons is Fe₃O₂

Learn more about ionic crystals here:

https://brainly.com/question/11638999

Answer:

Hey..! I know only 1st one answer

Answer:

it takes two hydrogen atoms for every oxygen atom to produce this reaction, so the mole ratio between hydrogen and oxygen is 2:1

Answer:

Mineral deficiencies can lead to a variety of health problems, such as weak bones, fatigue, or a decreased immune system.

Explanation:

There are five main categories of mineral deficiency: calcium, iron, magnesium, potassium, and zinc.

One major cause of mineral deficiency is simply not getting enough essential minerals from food or supplements.

Answer:

it can lead to a variety of health problems, such as weak bones, or a decreased immune system.

Explanation:

Answer:

this not easy

Explanation:

come on

Explanation:

Heat is transferred by conduction when adjacent atoms vibrate against one another or electrons move from one atom to another . Conduction is the most significant meanings of heat transfer within a solid or between solid objects informal contact.

We know, 1 mole of any element/compound contains 6.022 × 10²³ atoms/molecules .

Now, we have to calculate the number of molecules in 0.5 mole of sulfur dioxide, SO₂.

So, number of molecules of SO₂ in 0.5 mole is :

[tex]n = 0.5\times 6.022\times 10^{23}\\\\n = 3.011\times 10^{23}[/tex]

Therefore, number of molecules in 0.5 mole of SO₂ is 3.011 × 10²³.

Answer:

neutral!

pH = 7

Explanation:

⁄(⁄ ⁄•⁄ω⁄•⁄ ⁄)⁄

Answer:

B, C, E

Explanation:

did usatestprep

When the plunger is pulled out, pressure inside syringe decreases, lower pressure on balloon causes volume to increase,volume of the chamber also increases.

Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.

There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .

It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.

Learn more about pressure,here:

https://brainly.com/question/18107358

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Answer:

8

Explanation:

The atomic mass of an atom refers to the number of protons in the nucleus of an atom. Hence, an element with 6 valence electron mean that it has 6 electrons in its outermost shell.

The atomic Number of elements with 6 valence electrons cannot necessarily be the same, however, elements with 6 valence electrons belong to group six on the periodic table.

From the options given above, :

Atomic number of 8 :

Configuration : 2, 6

Atomic number of 10 :

Configuration : 2, 8

Atomic number of 12 :

Configuration : 2, 8, 2

Hence, only the element with atomic number of 8 has 6 valence electrons in its outer most shell, hence, the answer.