help me please i dont understand

Explanation:

Ca(OH) is a base

pOH = -Log[OH]

[OH] = 0.05

pOH = -Log(0.05)

pOH = 1.3

pH + pOH = 14

pH = 14 - pOH

pH = 14 - 2

pH = 12.7

Explanation:

The steps given in the question are incorrect.

Step 1 should be convert atoms to moles (n). Step 2 should be convert moles (n) to mass (m).

Step 1

Use dimensional analysis to convert the number of atoms to moles.

1 mole atoms = 6.022 × 10²³ atoms

n(Ag) = 2.3 × 10²⁴ Ag atoms × (1 mol Ag/6.022 × 10²³ Ag atoms) = 3.8193 mol Ag

Step 2

Convert the moles of Ag to mass.

mass (m) = moles (n) × molar mass (M)

n(Ag) = 3.8193 mol Ag

M(Ag) = atomic weight on the periodic table in g/mol = 107.868 g Ag/mol Ag

m(Ag) = 3.8193 mol × 107.868 g/mol = 412 g Ag = 410 g Ag rounded to two significant figures

The mass of 2.3 × 10²⁴ Ag atoms is approximately 410 g.

Answer:

[tex]\boxed {\boxed {\sf 3.8 \ moles \ of \ sulfur}}[/tex]

Explanation:

We are asked to convert a number of atoms to moles.

We can convert atoms to moles using Avogadro's Number, which is 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are atoms of sulfur. There are 6.022 ×10²³ atoms of sulfur in 1 mole of sulfur.

We use dimensional analysis to convert atoms to moles. This involves setting up ratios. Use Avogadro's Number and the underlined information to make a ratio.

[tex]\frac {6.022 \times 10^{23} \ atoms \ S}{1 \ mol \ S}[/tex]

We are converting 2.3 ×10²⁴ atoms of sulfur to moles, so we multiply by this value.

[tex]2.3 \times 10^{24} \ atoms \ S *\frac {6.022 \times 10^{23} \ atoms \ S}{1 \ mol \ S}[/tex]

Flip the ratio. It is equivalent, but it allows the units of atoms of sulfur to cancel.

[tex]2.3 \times 10^{24} \ atoms \ S *\frac {1 \ mol \ S}{6.022 \times 10^{23} \ atoms \ S}[/tex]

[tex]2.3 \times 10^{24} *\frac {1 \ mol \ S}{6.022 \times 10^{23} }[/tex]

[tex]\frac {2.3 \times 10^{24} }{6.022 \times 10^{23} } \ mol \ S[/tex]

[tex]3.819329127 \ mol \ S[/tex]

The original measurement of atoms (2.3 ×10²⁴) has 2 significant figures, so our answer must have the same. For the number we calculated that is the tenths place. The 1 in the hundredths place to the right (3.819329127) tells us to leave the 8 in the tenths place (3.819329127).

[tex]3.8 \ mol \ S[/tex]

2.3 ×10²⁴ atoms of sulfur is equal to approximately 3.8 moles of sulfur.

Answer:

La comida es un sólido y no podemos vivir sin comida. Algunos sólidos son buenos conductores de calor y electricidad; otros son aislantes. Los sólidos se utilizan todos los días en la vida.

Answer:

The correct answer is - alpha particle and positron.

Explanation:

In this question, it is given that, 38^88Sr decays to 34^84Kr, which means there is an atomic number decrease by 4, 38 to 34, and atomic mass decreases by 4 as well 88 to 84.

A decrease in the atomic mass is possible only when there is an emission of the alpha particle as an alpha particle is made of 2 protons and 2 neutrons. If an atom emits an alpha particle, there is a change in atomic number as it decreases by two, and its mass number decreases by four.

So after the emission of an alpha particle, the new atom would be

38^88Sr=> 36^84X => 34^84Kr

so there is also two positron emission that leads to decrease in atomic number by one with each emission:

38^88Sr=> 2^4He+ 36^84X => 36^84X + 2(1^0β+) => 34^84Kr

Positron decay is the conversion of a proton into a neutron with the emission of a positron that causes the atomic number is decreased by one, which causes a change in the elemental identity of the daughter isotope.

Answer: 52.17%

Explanation:

Number of matches in the box = 46

Number of matches that lit on the first strike = 22

Number of matches that did not light on the first strike = 46 - 22 = 24

Therefore, the percentage of the matches in the box did not light on the first strike will be:

= (Number of matches that did not light on the first strike / Number of matches in the box) × 100

= 24/46 × 100

= 52.17%

Therefore, the percentage of the matches in the box that did not light on the first strike is 52.17%.

Answer:

the name of reaction that produces esters is dehydration.

Answer:

The answer is A: The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster.

Explanation:

Think about it, if you boil water, whatever you put in the water is going to move around faster than if you put something in standing water.

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The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster. The correct answer is A.

Food coloring, or color additive, is any dye, pigment, or substance that imparts color when it is added to food or drink.

The food coloring we add to the water is pushed around by the water molecules. Since the molecules in warm water move around faster, the food coloring spreads out quicker in warm water than in cold water.

From the table, we can say that the water in glass B was heated by Ted and the molecules of food coloring spread out quickly in warm water and they have greater kinetic energy and move faster.

On the other hand, in glass A, the water is cold, so food coloring will not dissolve quickly.

Therefore, The water in Glass B was heated; therefore, the particles in Glass B have greater kinetic energy and move faster. The correct answer is A.

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Answer:

A

Explanation:

Two parents are involved in Sexual Reproduction but only one is involved in Asexual Reproduction.

Answer:

D

Explanation:

The correct answer would be that the thermal energy of the sun is transferred to the pavement.

Thermal energy refers to the internal energy possessed by a system by virtue of the movement of molecules within such a system. In other words, it is the heat energy possessed by a system.

When the thermal energy from the sun warms the pavement, it means that the thermal energy from the sun has been successfully transferred to the pavement. Thermal energy can be transferred by conduction, convection, or by radiation depending on whether the system is a solid, liquid, gas respectively.

The correct option is, therefore, D.

Answer:

The answer is in the explanation.

Explanation:

The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.

The reaction that explain this use is:

KHP + NaOH → KNaP + H2O

where 1 mole of KHP reacts per mole of NaOH

That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added

With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.

The moles of KHP are obtained from the volume and the concentration as follows:

Volume(L)*Concentration (Molarity,M) = moles of KHP

If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.

Answer:

The volume of the base is 0.05819·x L, where x is the number of moles of base that combines with one mole of sulfuric acid

Explanation:

The volume of the sulfuric acid, V = 25.3 mL = 25.3 × 10⁻³ L

The concentration of the sulfuric acid, c = 2.30 M

The concentration of the base, [tex]c_{base}[/tex] = 1.00 M

Let the mole ratio of the acid to base be 1 : x

The number of moles of sulfuric acid present, n = c × V

∴ n = 2.30 M/L × 25.3 × 10⁻³ L = 0.05819 moles

The number of moles of sulfuric acid present, n = 0.05819 moles

1 mole of sulfuric acid combines with x moles of base

Therefore, 0.05819 moles of sulfuric acid will combine with 0.05819·x moles of base

The number of moles of base, [tex]n_{base}[/tex] = 0.05819·x moles

Therefore, the volume of base, [tex]V_{base}[/tex] = [tex]n_{base}[/tex]/[tex]c_{base}[/tex]

∴  [tex]V_{base}[/tex] = 0.05819·x/1 ≈ 0.05819·x L

The volume of base,  [tex]V_{base}[/tex] ≈ 0.05819·x L.

Answer:

because the load arm is greater than the effort arm. As we know that when the load arm is greater than the effort arm, the mechanical advantage will always be lesser than one, which results in gain in speed

Answer:

An indication of calories consumed during anaerobic energy production

Explanation:

RER stands for respiratory exchange ratio, which is the ratio of the volume of carbon dioxide, CO₂, produced to the volume of oxygen, O₂ used in metabolism. RER is used in determining the respiratory quotient during aerobic exercise and rest, from which it can be determined if carbohydrate or fat is the source of fuel consumed in the production of energy for the body through metabolism

Therefore, the answer that is not correct is an indication of calories consumed during anaerobic energy production

mercury is not a mixture it is a element

Answer:

mercury

Explanation:

Answer:

0.289J of heat are added

Explanation:

We can relate the change in heat of a substance with its increasing in temperature using the equation:

q = m*ΔT*S

Where Q is change in heat

m is mass of substance (In this case, 0.0948g of water)

ΔT = 0.728°C

S is specific heat (For water, 4.184J/g°C)

Replacing:

q = 0.0948g*0.728°C*4.184J/g°C

q = 0.289J of heat are added

Answer:

5.17 percentage is water

Explanation:

answer from gauth math

Answer:

Answer is: elements in the same group have similar chemical properties. Periodic law is the arrangement of the elements in order of increasing atomic number.

Explanation:

"Its bonds are formed by large differences in electronegativity" is the statement among the choices given in the question that is generally true about CaCl2.

Answer:

60.55%

Explanation:

nO3=155/48

nO2 used: 3/2nO3=4.84375

percent yield: 4.84375/8=60.55%

answer is wildlife sanctuary

Answer:

a wildlife sanctuary

Explanation:

Answer:

I think it's answer would be A

Answer:

No Sodium(Na) in methylene

Explanation:

Methylene is an organic compound

Explanation:

The given molecule is

H3C - C ≡ C - CH3

The numbering order is shown below:

H3C - C ≡ C - CH3

    1     2     3     4

So, the alkyne group is in the second position.

The carbon chain has four carbons.

Hence, the IUPAC name of the given compound is:

2-butyne.

Answer:

Oxygen

Explanation:

Oxygen is abundant on earth

Answer:

Explanation:

The most prominent function of mitochondria is to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration and using sugar as fuel, and to regulate cellular metabolism .

Explanation:

The ionosphere is a shell of electron and electrically charged atoms and molecular that surrounds, the earth.

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The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm

The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).

Let's convert grams to moles (via molar mass).

Molar Mass (H₂) :  2 (1.008 g/mol)

Molar Mass (H₂) :  2.016 g/mol

1.8 grams H₂               1 mole

----------------------  x  ----------------------  =  0.893 moles H₂

                                2.016 grams

The Ideal Gas Law equation looks like this:

PV = nRT

In this equation,

After converting Celsius to Kelvin, you can put the given values into the equation and simplify to find the pressure.

P = ? atm                                R = 0.0821 L*atm/mol*K

V = 4.3 L                               T = 27 °C + 273.15 = 300.15 K

n = 0.893 moles

PV = nRT

P (4.3 L) = (0.893 moles) (0.0821 L*atm/mol*K)( 300.15 K)

P (4.3 L) =  22.0021

P = 5.12 atm

Therefore, The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm

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Answer:

D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.

Explanation:

Answer:

ném NaOH vào thì th AlCl3 tan hết còn lại kết tủa Fe(OH)3 lần.

Lọc kết tủa riêng phần dung dịch tan riêng

Rồi Cho HCl vô lại là xong

Explanation: