3. Hand sanitisers use disinfecting chemicals which kill microorganisms and evaporate quickly after doing so.
(a) Explain, in terms of the kinetic particle theory, what happens to the particles in the disinfectant when
it evaporates.
(b) Based on your answer in (a), explain if your hand will feel cooler or warmer when using hand sanitisers.
(c) The frequent use of some hand sanitisers can cause some people to develop dry, irritated skin. To reduce this
side effect, some hand sanitisers mix moisturisers with the disinfectant chemicals. Predict if the disinfectant
or the moisturiser has a higher boiling point. Explain your answer.
Hint Moisturisers keep hands moist for an extended period of time.

NaNO3 has a solubility of 80 grams per 100 grams of water at 10oC. (It seems to be somewhat less than 80 grams, but after rounded off, it's practically 80 grams.)

• Assume we just required 60 mL of NaNO3 solution at 10oC. Further Information: Because the solubility of solids rises with temperature, solutes whose curves go higher with increasing temperature are often solids.

Thus the solution in issue is saturated, or even somewhat supersaturated — but you're probably correct.

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Answer:

To determine the age of the ancient cloth, we can use the concept of radioactive decay and the half-life of Carbon-14.

Carbon-14 is a radioactive isotope of carbon, which decays over time into nitrogen-14 through beta decay. The half-life of Carbon-14 is 5614 years, which means that after 5614 years, half of the original amount of Carbon-14 in a sample will have decayed.

In this case, the cloth contains only ¼ of its original Carbon-14. This means that three half-lives have passed since the cloth was first created, as each half-life reduces the amount of Carbon-14 by half.

To determine the age of the cloth, we can use the following formula:

N = N0(1/2)^t/T

where N is the current amount of Carbon-14 in the cloth, N0 is the original amount of Carbon-14 in the cloth, t is the time that has passed, and T is the half-life of Carbon-14.

We know that N = ¼ N0, and T = 5614 years. Plugging these values into the formula, we get:

¼ N0 = N0(1/2)^(3/T)

Solving for t, we get:

t = (3/T) * log(2)

Substituting in T = 5614 years, we get:

t = (3/5614) * log(2) ≈ 1,684 years

Therefore, the cloth is approximately 1,684 years old.

In summary, we can use the concept of radioactive decay and the half-life of Carbon-14 to determine the age of the ancient cloth. By knowing the current amount of Carbon-14 in the cloth, we can calculate the time that has passed since it was first created using a simple formula. In this case, the cloth is approximately 1,684 years old.

Answer:

36.82 is 37 when you round it

Explanation:

:)

Answer:

the water sample with higher salinity will have greater mass, and it will therefore be more dense.

Explanation:

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H2 is the limiting reactant in this reaction. Water is generated when 5.00 g of H2 and 10.0 g of O2 react. Because there is 10.0 g of surplus reagent, 10.0 g of H2O is generated.

Calculate the amount of moles of product that can be generated from the limiting reactant using mole ratios. To get the equivalent mass of the product, multiply the number of moles by its molar mass. Divide the molar masses of each component to get the mass in moles. Create a balanced equation and calculate the molar ratio.

Examine the formula and compare the moles. In a chemical process, the limiting reagent is the reactant that will be totally consumed. The reaction cannot continue after that reactant is depleted. As a result, it prevents the reaction from proceeding. The surplus reagent is the reactant that may continue to react if the other was not consumed.

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If 5.00L of nitrogen completely reacts with hydrogen at a pressure of 3.00atm and a temperature of 298k,approximately 20.67 grams of ammonia will be produced.

The balanced chemical equation for the reaction between nitrogen and hydrogen to form ammonia is:

N2 + 3H2 → 2NH3

We can use the ideal gas law to calculate the number of moles of nitrogen:

PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the gas constant (0.0821 L atm mol K), and T is the temperature in Kelvin.

Rearranging the equation, we get:

n = PV/RT

Substituting the given values, we get:

n = (3.00 atm) (5.00 L) / (0.0821 L atm mol K) (298 K)

n = 0.607 mol

n(NH3) = 2 × n(N2) = 2 × 0.607 mol = 1.214 mol

Mass(NH3) = n(NH3) × M(NH3) = 1.214 mol × 17.03 g/mol ≈ 20.67 g

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Answer:2, 7, 4, 6

Explanation:

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

Answer:

It would take approximately 81.65 kJ (or 81,650 J) of heat to convert 230.0g of ice at -10C to water at 0C.

Explanation:

To calculate the amount of heat needed to convert ice at -10°C to water at 0°C, we need to consider two steps:

1. Heating the ice from -10°C to 0°C (heat required to raise the temperature of ice)

2. Melting the ice into water at 0°C (heat required to change the state of ice)

Let's first calculate the heat required for step 1:

Q1 = m × c × ΔT

where Q1 is the heat required, m is the mass of the ice, c is the specific heat capacity of ice, and ΔT is the change in temperature.

The specific heat capacity of ice is 2.09 J/g°C, and ΔT is (0°C - (-10°C)) = 10°C.

So, Q1 = 230.0 g × 2.09 J/g°C × 10°C = 4827 J

Now, let's calculate the heat required for step 2:

Q2 = m × Lf

where Q2 is the heat required, m is the mass of the ice, and Lf is the latent heat of fusion of ice.

The latent heat of fusion of ice is 334 J/g.

So, Q2 = 230.0 g × 334 J/g = 76820 J

Therefore, the total amount of heat needed to convert 230.0g of ice at -10C to water at 0C is:

Qtotal = Q1 + Q2 = 4827 J + 76820 J = 81647 J

Therefore, it would take approximately 81.65 kJ (or 81,650 J) of heat to convert 230.0g of ice at -10C to water at 0C.

The pressure will be 1000 mmHg when the volume is decreased to 80% of the original volume.

Boyle's law, which states that at a constant temperature, the pressure and volume of a gas are inversely proportional.

We can use Boyle's law. This means that:

P 1V1 = P2V2

Where

In this case, we know that the initial pressure (P1) is 800 mmHg and the initial volume (V1) is 1600 cm3. We want to find the final pressure (P2) when the volume (V2) is decreased to 80% of the initial volume:

V2 = 0.8V1 = 0.8 x 1600 cm3 = 1280 cm3

Substituting these values into Boyle's law, we get:

P1V1 = P2V2

800 mmHg x 1600 cm3 = P2 x 1280 cm3

Solving for P2, we get:

P2 = (800 mmHg x 1600 cm3) / 1280 cm3

P2 = 1000 mmHg

Therefore, the pressure will be 1000 mmHg when the volume is decreased to 80% of the original volume.

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When Hydrogen gas was cooled from 15 C to -15 C by use of the formula we get the value of the original volume as 671.875 mL.

Charles' Law describes the link that exists between the volume and temperature of a specific amount of ideal gas kept at constant pressure.

This rule says that for a given amount of gas at constant pressure, as the temperature rises, the volume of the gas rises, and as the temperature falls, the volume of the gas falls because temperature is directly proportional to the energy of movement of the gas molecules. That is, the volume of the gas is precisely proportional to its temperature.

The kinetic energy of a gas's molecules is exactly proportional to its absolute temperature, according to the kinetic theory of gases. The kinetic energy of the component molecules reduces as the temperature of the gas falls.

We have,

v1 t1 = v2 t2

v1 = x

v2 = 750 mL

t1 = 15 + 273 = 288 K

t2 = -15 + 273 = 258 K

putting the values in the equation,

x(288) = (750)(258)

x = 193500 / 288

x = 671.875 mL

So the original volume was 671.875 mL.

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The molarity of the stock solution is 1.05 M.

We can use the equation for dilution to solve this problem:

M₁V₁ = M₂V₂

where M₁ is the initial molarity (of the stock solution), V₁ is the initial volume (in mL) of the stock solution, M₂ is the final molarity (after dilution), and V₂ is final volume (in mL) of diluted solution.

In this case, we know that V₁ = 22.0 mL, V₂ = 50.0 mL, and M₂ = 0.458 M. We want to solve for M₁.

Plugging in the values, we get:

M₁(22.0 mL) = (0.458 M)(50.0 mL)

Simplifying and solving for M₁, we get:

M₁ = (0.458 M)(50.0 mL) / (22.0 mL)

M₁ = 1.05 M

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The molarity of the solution is 1.11 M (rounded to 2 decimal places). To find the molarity (M) of the solution, we need to know the number of moles of NaCl and the volume of the solution in liters.

Although a solution's molarity is determined by the moles of solute divided by the volume of the solution in litres, a solution's molality is determined by the moles of solute divided by the mass of the solvent in kilogrammes.

The number of moles of NaCl can be calculated using its molar mass and the given mass of NaCl:

Number of moles = mass / molar mass

The molar mass of NaCl is 58.44 g/mol (22.99 g/mol for Na + 35.45 g/mol for Cl).

Number of moles of NaCl = 65 g / 58.44 g/mol = 1.1138 mol (rounded to 4 decimal places)

The volume of the solution is given as 1 liter.

Now we can use the formula for molarity:

Molarity (M) = number of moles / volume (in liters)

M = 1.1138 mol / 1 L = 1.1138 M (rounded to 2 decimal places)

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4.2 gram should the chef mass out of a chocolate chip cookie recipe calls for 0. 050 moles of baking soda. This calculated by using mole concept.

Mass is equal to the number of moles multiplied by the molar mass of substance. We know that the number of moles is equal to the actual given mass of the substance over its molar mass.

      m = n x M.

The term molar mass of a chemical compound is defined as the ratio between the mass and the amount of substance of any sample of said compound. It is a bulk, not molecular, property of a substance.

According to the mole concept, one mole of a compound contains Avogadro's number that is 6.022 x 1023 of molecules or formula units of ionic compound. The molar mass of a compound defined as the mass of 1 mole of that substance. Generally we can say the number of grams per mole of a compound.

putting the value in the expression we get,

mass =84 × 0.050

        =4.2 g.

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The rate of the reaction will also double and become 0.01068 m/s.

The Arrhenius equation can be used to determine the effect of temperature on reaction rates. A reaction's rate constant is related to temperature by the Arrhenius equation, which is as follows:

[tex]k = Ae^(^-^E^a^/^R^T^)[/tex]

where: k = rate constant

A = frequency factor

e = base of natural logarithms (2.71828...)E

a = activation energy

R = gas constant (8.314 J/(mol K))

T = temperature (in Kelvin)

Since k is directly proportional to the rate of a reaction, we can use the equation to determine the effect of temperature on the rate of a reaction. Doubling the temperature will result in the following changes:

If the temperature is doubled, [tex]T_2 = 2T_1[/tex]

The equation becomes:

[tex]k_2 = Ae^(^-^E^a^/^R^T^2)[/tex]

We can now substitute 2T1 for T2:

[tex]k_2 = Ae^(^-^E^A^/^R^(^2^T1^)[/tex]

Simplify:k2 = [tex]Ae^(^-^E^a^/^R^T^1) * e^(^-^E^a^/^R^T^1^)[/tex]

[tex]k_2 = k_1 * e^(^-^E^a^/^R^T^1^) * e^(^-^E^a^/^R^T^1^)[/tex]

[tex]k_2 = k_ 1* e^(^-^2^E^a^/^R^T^1^)[/tex] So, the rate constant doubles if the temperature is doubled since [tex]e^(^-^2^E^a^/^R^T^1^)[/tex] is positive.

Therefore, the rate of a standard reaction will be 0.00543 m/s x 2 = 0.01086 m/s if the temperature is doubled.

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Answer:

The solubility of KNO3 in water increases with temperature. At 50°C, the solubility of KNO3 in water is 34 g/100 g water. This means that at 50°C, 100 g of water can dissolve up to 34 g of KNO3.

To find out how much KNO3 must be dissolved in 50 g of water to yield a saturated solution at 50°C, we can set up a proportion:

34 g KNO3/100 g water = x g KNO3/50 g water

where x is the amount of KNO3 that must be dissolved in 50 g of water.

Solving for x, we get:

x = (34 g/100 g) x 50 g

x = 17 g

Therefore, 17 g of KNO3 must be dissolved in 50 g of water to yield a saturated solution at 50°C.

Explanation:

Answer:

Explanation:

This is the simple answer of this question with respect to 60 degree temperature but question requirement  is 50 so we will do it according to 50 degree temperature

0. 1 M solutions of each of the following salts are: NaCN will be basic, KNO₃ is Neutral, NH₄CI is Acidic, NaHCO₃ is Basic, and Na₃PO₄ will be Basic.

NaCN: Basic, When NaCN dissolves in water, it dissociates into Na+ and CN⁻. The CN⁻ ion can act as a weak base by reacting with water to form OH⁻ and HCN. It will be shown by the following equation:

CN⁻ + H₂O ↔ OH⁻ + HCN

Since the formation of OH⁻ ions leads to an increase in pH, NaCN solution is basic.

KNO₃: Neutral, When KNO₃ dissolves in water, it dissociates into K+ and NO₃⁻. Neither of these ions reacts with water to form H⁺ or OH⁻ ions. Therefore, the solution remains neutral.

NH₄CI: Acidic, When NH₄CI dissolves in water, it dissociates into NH₄⁺ and Cl-. The NH₄⁺ ion can act as a weak acid by reacting with water to form H₃O⁺ and NH₃. It will be shown by the following equation:

NH₄⁺ + H₂O ↔ H₃O⁺ + NH₃

Since the formation of H₃O⁺ ions leads to a decrease in pH, NH₄CI solution is acidic.

NaHCO₃: Basic, When NaHCO₃ dissolves in water, it dissociates into Na⁺ and HCO₃⁻. The HCO₃⁻ ion can act as a weak base by reacting with water to form H₂O and CO₃²⁻. It will be shown by the following equation:

HCO₃⁻ + H₂O ↔ H₂CO₃ + OH⁻ ↔ CO₃²⁻ + 2H₂O

Since the formation of OH⁻ ions leads to an increase in pH, NaHCO₃ solution is basic.

Na₃PO₄: Basic, When Na₃PO₄ dissolves in water, it dissociates into 3Na+ and PO₄³⁻. The PO₄⁻ ion can act as a weak base by reacting with water to form HPO₄⁻ and OH⁻. It will be shown by the following equation:

PO₄³⁻ + H₂O ↔ HPO₄²⁻ + OH⁻

Since the formation of OH⁻ ions leads to an increase in pH, Na₃PO₄ solution is basic.

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The number of ion in 0.2 mole of (NH₄)₃PO₄ is found to be 2.4  x 10²³.

The number of ions and the number of moles of a compound are related to each other as,

Moles = Number of ions/Avogadro number = molar mass/given mass

Avogadro number = 6.022 x 10²³

Here, (NH₄)₃PO₄ will give two ions after dissociation will give two ions, so, the number of moles will be equal to two times of the number of particles of the compound. So, the total moles of ions will be 0.4 moles.

Putting all the values is the formula,

6.022 x 10²³ x 0.4 = Number of ions

So, finally after solving, we get, 2.4  x 10²³ as the number of ions in the compound of (NH₄)₃PO₄.

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Answer:

0.064 moles

Explanation:

First, we need to convert the temperature in Kelvin, which can be done by adding 273 to the temperature in Celsius. So the temperature in Kelvin is 294 K. We can now use the Ideal Gas Law, PV = nRT, to solve for the number of moles, n. Rearranging the equation gives us n = PV/RT. Plugging in our values gives us n = (0.553 atm)(1.90 L)/[(0.0821 L·atm/K·mol)(294 K)] = 0.064 mol. Therefore, there are 0.064 moles of krypton gas present in the container.

Answer:

Explanation:

To determine which metal is more reactive, you could refer to the reactivity series of metals. The reactivity series is a list of metals arranged in order of their reactivity with the most reactive metal at the top of the list and the least reactive metal at the bottom.

If you have a copy of a chemistry textbook, you could refer to the chapter on the reactivity of metals or look up the reactivity series in the index. Alternatively, you could consult a periodic table that includes the relative reactivity of the elements. The reactivity series is also often included in reference materials such as handbooks, tables, and charts of chemical data.

Answer:

Reactant molecules collide less frequently.

Explanation:

The decrease in temperature decreases the kinetic energy of the reactant molecules leading to decreased chances of collisions of the reactants for the formation of the products.

Answer:

hydrogen sulfide (H2S): covalent

Ammonia (NH3): covalent

Methane (CH4): covalent

Nitrous Oxide (N2O): covalent

Explanation:

o  Hydrogen sulfide (H2S is a covalent compound that is composed out of 2 hydrogen atoms.

o  Because one nonmetal combines with another nonmetal to form a covalent compound, ammonia (NH3) is a covalent compound.

o  CH4 (Methane) is a covalent (nonpolar covalent) compound because when two nonmetals combine, they form a covalent compound.

o  Nitrous Oxide (N2O) is a covalent bond. Since the N-N-O bond angle is 1800, the central N makes one covalent bond with N and O.

Answer:

All of the compounds listed above have covalent bonding.

according to science direct,

A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. These electrons are simultaneously attracted by the two atomic nuclei.

all of the compounds above share 1 or more pairs of electrons.

A- the ratio of mol water to mol dry gas is 10/100, B- The required air feed rate is 166.67 kmol/h, C- composition of exhaust gas steam is 100% of water.

a) On a wet basis, the molar composition of the gas is 70.0 mol % methane, 15.0 mol % ethane, 5.0 mol % ethylene, and 10.0 mol % water. On a dry basis, the molar composition is 78.26 mol % methane, 17.74 mol % ethane, 4.26 mol % ethylene, and 0 mol % water. The ratio of mol water to mol dry gas is 10.0/100.

b) If 100 kg/h of the fuel is to be burned with 30% excess air, the required air feed rate is 133.33 kmol/h. If the combustion is only 75% complete, the air feed rate would be 166.67 kmol/h.

c) If the fuel burns to 100% completion, the composition of the exhaust gas stream will be 0 mol % methane, 0 mol % ethane, 0 mol % ethylene, and 100 mol % water.

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At the same temperature, the pH of a 0.001 M Ca(OH)2 aqueous solution will be higher than that of a 0.001 M NaOH(aq).

The pH value of a solution is determined by the concentration of hydrogen ions in the solution. Higher hydrogen ion concentration in a solution leads to lower pH values, while lower hydrogen ion concentration results in higher pH values. The chemical formulas of the two solutions are: Ca(OH)2(aq) → Ca2+(aq) + 2OH-(aq) NaOH(aq) → Na+(aq) + OH-(aq). The hydroxide ion (OH-) concentration of a Ca(OH)2 solution is twice that of a NaOH solution of equal concentration. This is due to the fact that 1 mole of Ca(OH)2 produces two moles of OH- ions, whereas 1 mole of NaOH produces only 1 mole of OH- ions. As a result, the pH of Ca(OH)2 is higher than that of NaOH.

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7. a. Carbon dioxide (CO2) is the gas that might be dissolved in the blood on the right side of the heart.

b. CO2 is produced as a waste product of cellular respiration, which is the process by which cells produce energy.

c. Before the blood enters the left side of the heart, CO2 is transported from the tissues to the lungs, where it is exchanged for oxygen.

8. The flow pattern of the blood inside the circulatory system is unidirectional,  with the blood flowing from the right atrium to the right ventricle, then to the lungs, and from the lungs to the left atrium and left ventricle, and finally to the body.

The entrances and exits to the heart need valves to maintain the unidirectional flow pattern of the blood.

The atrioventricular valves (tricuspid valve on the right side and mitral valve on the left side) prevent the backflow of blood from the ventricles to the atria, while the semilunar valves (pulmonary valve on the right side and aortic valve on the left side) prevent the backflow of blood from the arteries to the ventricles.

The heart also needs a pacemaker to coordinate the contraction of the atria and the ventricles to ensure the efficient pumping of blood.

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Answer:

The name of the formula AuCN is gold cyanide.

A 150 mL solution with a concentration of 12 M whose volume is increased to 600 mL will have a new concentration of 3 M.

Assuming the amount of solute remains constant, we can use the formula:

C1 x V1 = C2 x V2

where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.

Plugging in the values, we get:

12 M x 150 mL = C2 x 600 mL

Solving for C2, we get:

C2 = (12 M x 150 mL) / 600 mL

C2 = 3 M

Therefore, the new concentration is 3 M.

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Answer:

The volume of water containing 150g of sucrose is 600 mL.

Step by step explanation:

To solve this problem, we need to first determine the total mass of the solution. We know that the mass fraction of water is 0.8, which means that water makes up 80% of the solution.

Therefore, the mass fraction of the other component (sucrose) is 0.2, or 20%.

Let's assume we have a total mass of 1 kg (1000 grams) of solution, then the mass of water in the solution would be:

Mass of water = 0.8 x 1000 grams = 800 gramsSince the mass of sucrose is 20% of the total mass,

we can calculate it as:

Mass of sucrose = 0.2 x 1000 grams = 200 grams

Now we can use the density of water to calculate the volume of water that contains 800 grams.

The density of water is approximately 1 gram per milliliter (g/mL).

Therefore, the volume of water that contains 800 grams is:

Volume of water = 800 grams / 1 g/mL = 800 mL

Finally, we can calculate the volume of water that contains 150 grams of sucrose by using the mass ratio of sucrose to water, which is:

150 grams of sucrose / 200 grams of sucrose = 0.75

This means that the volume of water containing 150 grams of sucrose is 0.75 times the volume of water in the entire solution:

Volume of water containing 150g of sucrose = 0.75 x 800 mL = 600 mL

Therefore, the volume of water containing 150g of sucrose is 600 mL.

Where energy from the sun is enough to break the bonds between water molecules in the ice and convert them directly into water vapor without passing through the liquid phase.

What is Sublimation?

Sublimation is a physical process in which a solid substance is transformed directly into a gas without passing through the liquid phase. In other words, sublimation occurs when a solid substance changes its state directly to a vapor state, bypassing the liquid state.

Sublimation occurs when the vapor pressure of a solid exceeds the atmospheric pressure, causing the solid to transform into a gas without melting. This process requires energy to break the intermolecular bonds holding the solid together. This energy is typically supplied through heating or a decrease in pressure.

Water in Earth's polar regions can produce water vapor even when the temperature is very low due to a process called sublimation. Sublimation is a phase transition from a solid directly to a gas, without passing through the liquid phase. This process occurs when the vapor pressure of the solid (in this case, ice) exceeds the atmospheric pressure.

In the polar regions, the air is very cold and dry, with low atmospheric pressure. When the sun shines on the ice or snow, it provides energy that causes the surface layer of the ice to evaporate directly into water vapor without melting into liquid water.

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Answer: you have to do x+axis than you will get ur answer

Explanation:During a chemical reaction, all of the atoms that make up the reactants rearrange to form the products.