1
Answer the following questions by using the periodic table where necessary.
1. Which element is most reactive?
B. Ca
C. Ne
D. Ar
A. Na

The concentration of the strontium hydroxide, Sr(OH)₂ solution is 0.083 M.

The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.

The letters pH stand for "power of hydrogen" and the numerical value is defined as the negative base 10 logarithms of the molar concentration of hydrogen ions.

Mathematically;

pH = - log [H⁺]

pOH = 14 - pH

where;

[H⁺] = concentration  of hydrogen ions

[OH⁻] = concentration of hydroxide ions

pOH = 14 - 13.22

pOH = 0.78

The concentration of hydroxide ions in the solution is:

[OH⁻] = 10⁻⁰°⁷⁸

[OH⁻] = 0.166 M

The concentration of the strontium hydroxide, Sr(OH)₂ solution = 0.166/2 M

The concentration of the strontium hydroxide, Sr(OH)₂ solution = 0.083 M

Learn more about pH at: https://brainly.com/question/172153

#SPJ1

The amount of heat needed to boil 15.5 g of methanol (ch3oh). the molar heat of vaporization for methanol is 35.21 kj/mol. the molar mass of methanol is 32.04 g/mol.

To calculate the amount of heat needed to boil 15.5 g of methanol, we need to use the formula: Q = mL

Where Q is the heat energy, m is the mass of the substance, and L is the molar heat of vaporization.

First we need to find the moles of methanol:

moles = mass / molar mass

moles = 15.5 g / 32.04 g/mol = 0.4828 moles

Then we can calculate the heat energy required to boil the methanol:

Q = mL

Q = 0.4828 moles * 35.21 kJ/mol

Q = 17.04 kJ

So, 17.04 kJ of heat energy is required to boil 15.5 g of methanol.

To learn more about molar here:

https://brainly.com/question/8732513

#SPJ4

If 0.5 L of air at 203 k in an expandable container at constant pressure. The volume of air at 273 K would be 0.67 L.

The universal (or perfect) gas constant is 8.314 joules per kelvin per mole, according to the ideal gas law, which stipulates that PV is equal to nRT. n is the number of moles of the gas.

The Ideal Gas Law states that when a gas is at a given temperature, pressure, and volume, it has an equal number of molecules (but not the same mass)

V₁=0.5 L

T₁=203 K

V₂= 273 K

V₂ = unidentified

Now, V₁/T₁=V₂/T₂

So,

0.5L/203 = V₂/273

V₂= 0.67 L

Learn more about Gas Law

brainly.com/question/13207402

#SPJ4

The number of mole of methane, CH₄ needed to produce 5.75 moles of water vapour is 2.875 moles

We'll begin by obtaining the moles of CH₄ that reacted from the balanced equation:

CH₄ + 2O₂ -> CO₂ + 2H₂O

From the balanced equation above,

2 moles of H₂O were obtained from 1 mole of CH₄

Using the above information, we can determine the number of moles of CH₄ needed for the reaction. Details below:

From the balanced equation above,

2 moles of H₂O were obtained from 1 mole of CH₄

Therefore,

5.75 moles of H₂O will be obtained from = (5.75 × 1) / 2 = 2.875 moles of CH₄

Thus, we can conclude that the number of moles of CH₄ needed is 2.875 moles

Learn more about number of mole:

https://brainly.com/question/23350512

#SPJ1

The equation must have the following form to be balanced: 4CO2 + 2H2O = 2C2H2 + 5O2

S8: O2 = 1/8; S8 utilized = 240/8 = 30SO2 generated is equal to the number of sulphur molecules used, which is 240. Stoichiometry is the name given to the study of chemical processes in mathematics. Numerous calculations can be done, such as stoichiometry, which is most usually performed with moles but can also be done with masses and even percentages. Stoichiometric ratio A stoichiometric ratio is important when considering the interactions between specific elements or molecules. This exact ratio of reactant to product coefficients is necessary for a reaction to occur properly. Let's discuss some problems you can run across when you learn about stoichiometry. Chemical Equations in Balance Equations needing to be balanced is a fairly common stoichiometric issue type. This is an essential chemistry skill since a reaction can only occur if the ratio of reactants to products is correct.possess. Additionally, it provides an essential framework for organic chemistry. Balance the ensuing reply: _ CO2 + _ H2O C2H2 + _ O2 To be balanced, equations must have an equal number of each element on both sides of the reaction. Before balancing the oxygen, you can start by balancing the carbons and hydrogens. The equation must have the following form to be balanced: 4CO2 + 2H2O = 2C2H2 + 5O2

Learn more about Carbons here:

brainly.com/question/22530423

#SPJ4

The mass of NO2 produced by the reaction is 24.61g when the initial mass of 16.07g NO, an excess of O2 is converted to product NO2.

Given the chemical reaction: 2NO(g) + O2(g) + 2NO2(g)

The equation is balanced.

The initial mass of NO is (m) = 16.07g

Here first we calculate the number of moles of NO is used = mass/Molar mass of NO

moles of NO used = 16.07/30 = 0.535

An excess of O2 is used so we can neglect that.

Now calculate the moles of NO2 produced.

moles of NO2 =  0.535 x 2 mol(NO2) / 2mol(NO) =  0.535

we can determine that NO is the limiting reactant.

To convert from moles to mass, use the product's molar masses.

Molar mass of NO2 = 46g/mole

Then the mass of NO2 produced = 0.535 x 46 x 1 = 24.61g

Hence the mass of NO2 produced by the reaction is 24.61g

To learn more about reactant click here https://brainly.com/question/17096236

#SPJ4

The result of the four trials by the student is precise to the actual weight of the lead block.

Since we have been alive for millions of years, we have acquired a sense of measurement, which is necessary for us to comprehend the outside world. Tools that provide scientists a number are necessary for measurements. The issue here is that every measurement, using any measuring device, has some level of uncertainty in the outcome. Error is the name given to this uncertainty. When taking measurements, accuracy and precision are two crucial considerations. These two phrases describe how closely a measurement resembles a value that is understood or accepted.

Accuracy refers to an instrument's capacity to measure exact values. It is, in other words, the degree to which the measured value resembles a standard or real value. Accuracy is possible by obtaining quick readings.

The precision of a substance is defined as the similarity between two or more measurements.

To know more about precision from the link

brainly.com/question/1695072

#SPJ4

The number of moles of water that are produced from the reaction of the combustion of 0.20 moles of ethane, C₂H₆ is 0.6 moles.

The number of moles of water that are produced from the reaction of the combustion of 0.20 moles of ethane, C₂H₆ is obtained from the mole ratio as given in the equation of the reaction.

The equation of the reaction is given below as follows:

2 C₂H₆ + 5 O₂ ---> 2 CO₂+ 6 H₂O

From the equation of the reaction, 6 moles of water are produced from the combustion of 2 moles of ethane.

The mole ratio is 1 : 3

The number of moles of water produced from 0.2 moles of ethane = 0.2 * 3 moles

The number of moles of water produced = 0.6 moles

Learn more about mole ratio at: https://brainly.com/question/26023

#SPJ1

Complete question:

How many moles of H₂O is formed from 0.20 moles of C₂H₆?

Equation of the reaction: 2 C₂H₆ + 5 O₂ ---> 2 CO₂+ 6 H₂O

To calculate the gas constant using the data provided, you would use the ideal gas law equation: PV = nRT.

Assuming that the amount of propane (n) is given in moles and the volume (V) is given in liters, the ideal gas law equation can be rearranged to solve for R:

R = PV/nT

Given that the pressure (P) is 1.00 atm and the temperature (T) is 294.6 K, you can plug in these values and solve for R:

R = (1.00 atm) * (V) / (n) * (294.6 K)

Without knowing the exact values for V and n, it is not possible to determine the exact value for R. However, it is important to note that the units of R are L atm mol-1 K-1, and option A is the only choice that has the correct units, so the answer is A. 1.858 L atm mol-1 K-1.

To learn more about gas constant:

https://brainly.com/question/20348074

#SPJ4

The value of the Kp is 0.0036.

Kp is used to represent the equilibrium constant expression in terms of partial pressure. Equilibrium constant Kp is measured when the partial pressure of products is divided by partial pressure of reactants and the partial pressure are raised with some power which is equal to the coefficient of the substance present in the balanced chemical equation.

                      A    +     B     ⇆     2C

t = 0              3.4         7.5            0

Equilibrium  3.4 - x     7.5 - x      2x

According to the question,

2x = 0.57

⇒ x = 0.57/2 = 0.285

Kc = (2x)²/{(3.4 - x) (7.5 - x)}

⇒Kc = (0.285)²/(3.115 × 7.215)

⇒Kc = 0.081225/22.47425

⇒Kc = 0.0036

The given question is incomplete so I have answered it on general basis.

Learn more about Equilibrium constant from the link given below.

https://brainly.com/question/9238135

#SPJ4

The element whose mass number is 115 and contains 65 neutrons per atom, its atomic number will be-

Atomic Number (Z) = Mass Number (A) - Number of Neutrons (N)

Z = 115 - 65

Z = 50

So, the atomic number for the given element is 50.

Tin is the element with the symbol Sn which has an atomic number of 50. Tin is classified as a post-transition metal. Tin is a silver-coloured metal and remains solid at room temperature.

The atomic number is the number of protons in an atom. Due to this, it is sometimes named the proton number. The atomic number is indicated by the letter Z. The symbol Z is derived from the German word Zahl, which means several numerals.

To know more about atoms, visit here:

https://brainly.com/question/13654549

#SPJ4

The time that the object was moving is 139.6 seconds.

To determine the time (t) that the object was moving, you can use the formula:

t = d

    v

where,

d = the distance the object travels

v = its velocity

d = 45.6 m

v = 0.327 m/s

Substituting the given values:

t = 45.6 m

    0.327 m/s

t = 139.6 seconds

Hence, the time that the object was moving is 139.6 seconds.

Learn more about Calculating the time on

https://brainly.com/question/24304505

#SPJ1

Excessive burning of fossil fuels such as coal, oil, and natural gas can have a significant impact on our planet. The primary way in which burning fossil fuels affects the planet is through the release of greenhouse gases, such as carbon dioxide (CO2) into the atmosphere.

These gases trap heat from the sun, which causes the Earth's temperature to rise, a phenomenon known as global warming. This can lead to a variety of negative effects, such as:

Climate change: The increase in temperature can cause more frequent and severe weather events such as heat waves, droughts, and floods. It can also cause sea levels to rise and glaciers to melt, leading to coastal flooding and changes in precipitation patterns.

Loss of biodiversity: Warmer temperatures can cause species to migrate or die out, leading to a loss of biodiversity. Changes in precipitation patterns can also affect the survival of certain species.

Ocean acidification: The ocean absorbs a large amount of CO2, which can cause the pH of seawater to decrease, making it more acidic. This can harm marine life, especially those that have shells or skeletons made of calcium carbonates, such as coral and certain types of plankton.

Learn more about global warming here:

https://brainly.com/question/12908180

#SPJ4

Coal, oil, and natural gas are examples of fuels that store chemical energy. The chemical energy in these fuels is transformed into heat energy when they are burnt. Some fuels, known as fossil fuels.

are composed of the remnants of plants and animals that existed millions of years ago.Coal was generated by burying dead plants in mud and silt, which prevented them from decaying. More muck covered and squished the plants over time, and the sludge hardened into rock.Coal, oil, and natural gas are examples of fuels that store chemical energy. The chemical energy in these fuels is transformed into heat energy when they are burnt. Some fuels, known as fossil fuels. The dead plants were converted into coal. Plants and animals that fell to the sea floor and were covered by silt produced oil and Coal, oil, and natural gas are examples of fuels that store chemical energy. The chemical energy in these fuels is transformed into heat energy when they are burnt.

learn more about fossil fuels  here:

https://brainly.com/question/3371055

#SPJ4

Atomic mass is the sum of the total number of protons and neutrons in an atom, while atomic number is the number of protons in the nucleus of an atom.

To learn more about The difference between atomic mass and atomic number refer to:

https://brainly.com/question/2093142

#SPJ1

Answer:

The answer is B

Explanation:

That's what the person above said.

Based on the given information, B: Ethanol is the compound that has the strongest intermolecular forces.

Intermolecular forces (IMF) are the forces that hold molecules of a substance together. The strength of IMF is directly related to the boiling point of a substance. So, the stronger the IMF, the higher the boiling point will be.

The information provides the heat of vaporization (DHvap) for each substance, which is the energy required to convert a liquid into a gas. The higher the DHvap value, the stronger the IMF because more energy is required to overcome the forces that hold the molecules together.

When comparing the DHvap values, we can see that Ethanol (C2H5OH) has the highest DHvap value of 39.3 kJ/mol, followed by water (H2O) with 40.8 kJ/mol. This means that ethanol has stronger intermolecular forces than water, that's why ethanol has a higher boiling point than water.

Therefore, based on the DHvap values, Ethanol has the strongest intermolecular forces.

You can learn more about DHvap values at

https://brainly.com/question/28810587

#SPJ4

The de Broglie wavelength of a particle is given by the equation:

λ = h / p.

Where λ is the de Broglie wavelength, h is Planck's constant (6.62607015 x 10^-34 Js) and p is the momentum of the particle.. The de Broglie wavelength of an oxygen molecule at room temperature is on the order of 4.8 x 10^-10 m. This wavelength is much smaller than the average distance between oxygen molecules in a gas at 1 atm, which is about 2 x 10^-10 m. This means that the de Broglie wavelength of an oxygen molecule is much smaller than the distance between the oxygen molecules and it is not possible to see the interference or diffraction patterns of individual molecules in most cases.

Learn more about momentum here:

https://brainly.com/question/24030570

#SPJ4

The half-life of carbon-12, the most common isotope of carbon, is approximately 5,730 years.

This means that after 5,730 years, half of the original amount of carbon-12 in a sample will have decayed into a stable isotope (nitrogen-14). Therefore, it would take approximately 11,460 years for three quarters of the original amount of carbon-12 in a sample to become stable. Importantly, carbon-12 is not radioactive and hence does not decay into a stable isotope, but it is used in carbon dating because it is a stable isotope of carbon. Dating depends on the decay of other isotopes, such as carbon-14 or radiocarbon.

Learn more about carbon 12 here: brainly.com/question/2113137

#SPJ4

The change in entropy Δs when 3.4 g of diethyl ether condenses at 34.6 °C is 4.1 J/K.

Enthаlpy (H) is defined аs the аmount of energy releаsed or аbsorbed during а chemicаl reаction. Entropy (S) defines the degree of rаndomness or disorder in а system.

The relаtionship between both pаrаmeters is given аs;

ΔS = ΔH ÷ T

ΔH = 26.7 KJ/mol for 1 mol of diethyl ether

number of moles = mаss ÷ molаr mаss

number of moles = 3.4 ÷ 72 = 0.04722

ΔH = 26700 × 0.04722 = 1260.77 J

T = 34.6 + 273 = 307.6 (upon converting to Kelvin temperаture)

ΔS = 1260.77 ÷ 307.6

ΔS = 4.1 J/K

Your question is incomplete, but most probably your full question can be seen in the Attachment.

For more information about entropy refer to the link:

https://brainly.com/question/13146879

#SPJ4

Answer:

15.6 moles

Explanation:

For every 2 moles of H3PO4 that is reacted, 6 moles of H2O are produced.

So if 5.2 moles of H3PO4 are reacted with calcium hydroxide, calculate the moles of H2O produced by this:

5.2 moles H3PO4 * (6 moles H2O / 2 mole H3PO4) = 15.6 moles H2O

Therefore 15.6 moles of H2O would be produced if 5.2 moles of H3PO4 are reacted with calcium hydroxide.

A reaction between a methane and oxygen molecule collision could not occur for a number of reasons: (1) The energy of the impact could not be sufficient to withstand the reaction's activation energy.

(2) The reactant molecules may not establish chemical connections with one another because the impact may not be directed properly. (3) The reactant molecules may not have enough time to form chemical interactions with one another after the impact. (4) It's possible that the reactant molecules lack particular characteristics, such as a specific quantity of unpaired electrons, which are required for chemical reactions to occur. (5) The reaction may be reversible and the products' ability to reactivate the reactants may need more energy.

the smallest component of a material that possesses both its chemical and physical characteristics. One or more atoms make up molecules.

learn more about molecules  here:

https://brainly.com/question/19556990

#SPJ4

Volume of one mole of gas at STP = 22.4 L

number of particles in one mole of any substance = 6.022 ×10²³

What is the mass of 9.30 mole of SiH₄ = 298.81

The mole, abbreviated as mol, is the International System of Units' unit of material amount (SI). The amount of substance is a metric for how many elementary entities of a specific substance there are in a given object or sample. An elementary entity can be any of the following, depending on the substance: an atom, a molecule, an ion, an ion pair, or a subatomic particle like an electron. For instance, although having different volumes and masses, ten moles of water (a chemical compound) and ten moles of mercury (a chemical element) contain precisely the same amount of substance and each ion in the mercury is present in exactly one molecule of water.

To learn more about mole from the given link

https://brainly.com/question/26416088

#SPJ4

1.81 x 10^24 Br-ions are present in 1.00 moles of FeBr3

Avogadro's number of representative particles is included in one mole of a substance.

6.02 x 1023 particles make up 1 mole.

How many of each sort of atom there are in a typical particle is indicated by the chemical formula of the molecule. One mole of iron(III) ions and three moles of bromide (Br-) ions make up the formula FeBr3, which states that. The quantity of Br- ions is thus:

1.81 × 1024 Br- ions from 3 x 6.0223

When thinking about atoms and molecules, a mole is a helpful unit of measurement. Compounds are created when modest whole-number ratios of atoms mix. Quantities are reported in moles for the purpose of employing mathematical relationships in computations since atoms of various elements have different masses. For instance, the proportion of iron(III) ions to bromide ions in FeBr3 is the same as the proportion of moles of iron(III) ions to moles of bromide ions, but not the proportion of masses of the two types of ions.

Learn more about br- ions   here:

https://brainly.com/question/14126889

#SPJ4

Given,

Amount of sodium atoms = 46 grams

To find,

The total number of sodium atoms present in the given amount of sodium atoms.

We can simply solve this numerical problem by using the following process:

As per stoichiometry;

1 mole of any element contains Avogadro's number of atoms, that is, 6.022 x 10^23 atoms.

And, the molar mass of any element is equal to the atomic mass of the same element.

=> If the given amount of an element/compound is equal to its molar mass, then it contains 6.022 x 10^23 atoms/molecules.

=> Total number of atoms/molecules present in the given amount of the element/compound

= (total given mass)/(molar mass) x 6.022 x 10^23

Now,

the molar mass of sodium = 23 grams

Total number of sodium atoms present in the given amount of sodium atoms

= (total mass)/(molar mass) x 6.022 x 10^23

= 46 grams / 23 grams x 6.022 x 10^23

= 2 moles x 6.022 x 10^23

= 12.044 x 10^23 = 1.2044 x 10^24 atoms

Hence, 1.2044 x 10^24 sodium atoms are present in the given amount of sodium atoms.

The graph below shows the phase change for water. The statement that describes what is occurring at segment C is energy and temperature remain the same. The correct option is D.

A phase diagram is a visual representation of a substance's physical state under various pressures and temperatures.

Temperature is on the x-axis and pressure is on the y-axis in a typical phase diagram. Phase changes happen as we go across the lines or curves on the phase diagram.

Therefore, the correct option is D. Energy and temperature remain the same.

To learn more about phase change, refer to the link:

https://brainly.com/question/30270780

#SPJ1

The question is incomplete. Your most probably complete question is given below: the graph is attached.

Answer:

Explanation:

Dipole-dipole interactions are a type of chemical bonding that occurs between two polar molecules. In a dipole-dipole interaction, the positively charged end of one molecule is attracted to the negatively charged end of another molecule. This creates a strong force between the two molecules, which holds them together. Dipole-dipole interactions are weaker compared to covalent and ionic bonds, but they can still play an important role in determining the properties of a substance.

The bromobenzene used in the experiment was equimolar to 3.7 grams of benzophenone. The correct answer is C. 

The stoichiometry of a chemical reaction tells us the relative amounts of reactants and products involved in the reaction. In this case, the reaction is between bromobenzene and benzophenone to form a new compound.

The balanced equation for this reaction is:

From the equation, we can see that one mole of bromobenzene reacts with one mole of benzophenone. Therefore, an equimolar amount of benzophenone is the same as the amount of bromobenzene used in the experiment. Since the molar mass of benzophenone is 182.23 g/mol, we can use this value to calculate the mass in grams by multiplying it with the number of moles.

To calculate the equimolar amount of benzophenone, we use the following formula:

Let's assume that the mass of bromobenzene used in the experiment is x. Hence:

Therefore, the equimolar amount of benzophenone is 3.7 grams.

This question should be provided with answer choices, which are:

The correct answer is C.

Learn more about stoichiometry here: brainly.com/question/25829169

#SPJ4

Answer:

At standard temperature and pressure (STP), which is defined as 0 °C (273.15 K) and 100 kPa (1 atmosphere), several elements exist as gases.

The elements that are gases at standard temperature and pressure include:

Helium (He)

Neon (Ne)

Argon (Ar)

Krypton (Kr)

Xenon (Xe)

Radon (Rn)

Hydrogen (H2)

Answer:

At standard temperature and pressure (STP), which is defined as 0 °C (273.15 K) and 100 kPa (1 atmosphere), several elements exist as gases.

The elements that are gases at standard temperature and pressure include:

Helium (He)

Neon (Ne)

Argon (Ar)

Krypton (Kr)

Xenon (Xe)

Radon (Rn)

Hydrogen (H2)

Answer: An element has 2 isotopes: 6X at 7.59% and 7X at 92.41%. What is the average atomic mass?

Explanation:

In a bid to  calculate the average atomic mass, we  multiply the fraction of each isotope by the mass number , then add them together.

This is more like weighted average, as shown below:

average atomic mass=(mass number of first isotope*fraction)+(mass number of second isotope*fraction)

average atomic mass=(6X*7.59%)+(7X*92.41%)

average atomic mass= 6.92X

Chaulmoogra oil has long-chain fatty acids, but the ethyl esters generated using the ball process include shorter-chain fatty acids. Because shorter chain fatty acids may more easily.

enter cell membranes, they are more quickly absorbed by the body. Furthermore, the ethyl esters are more water-soluble than the oil, allowing for improved absorption. The big, insoluble molecules of long-chain fatty acids in chaulmoogra oil are most likely responsible for the production of painful bubbles. The ethyl esters' short chain fatty acids are less prone to create such bubbles and hence less unpleasant.comparing the structures of chaulmoogra oil with the ethyl esters formed by the ball method, why do you think the ethyl esters might be more readily absorbed by the body (and not form the painful bubbles like the oil) The big, insoluble molecules of long-chain fatty acids in chaulmoogra oil are most likely responsible for the production of painful bubbles. The ethyl esters' short chain fatty acids are less prone to create such bubbles and hence less unpleasant.comparing the structures.

learn more about acids  here:

https://brainly.com/question/29796621

#SPJ4