Student 4 because a Bronsted-Lowry base always accepts a proton from an acid to form a conjugate acid.
Kb = 4x[tex]10^{-4}[/tex]
C 0.01
where C is concentration.
∵[OH-] = [tex]\sqrt{K.c}[/tex]
[oh-] = [tex]\sqrt{√4x10^{-4} D}[/tex]
= [tex]\sqrt{4*10^{-6} }[/tex] = [tex]\sqrt{2*10^{-3} }[/tex]
∴ H(+) = [tex]10^{-14} / 2*10^{-3} = 0.5*10^{-11}[/tex]
ph = - log ([tex]H^{+}[/tex])
= - log [tex](1/2*10^{-11})[/tex]
11 - log (1/2)
= 11 + 0.3010
= 11.3010
(~11-12).
In the Bronsted-Lowry definition of acids and bases, acids are proton H + donors and bases are proton acceptors. A conjugate base is formed when a Bronsted-Lowry acid loses a proton. Similarly, when a Brønsted-Lowry base gains a proton, a conjugate acid is formed. When a Bronsted acid or just an acid reacts with a Bronsted base or just a base a proton is transferred from the acid to the base. This forms another acid called the conjugate acid and another base called the conjugate base.
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how to identify oxides that don't dissolve in water?
Answer: The oxides of hard metal or the transition metals oxides like oxides of copper, zinc, iron, and chromium do not dissolve in water due to their limited basicity. Alkaline earth metal oxides also form hydroxides in water but these hydroxides themselves give slaked solutions and are not completely soluble.
Explanation: The oxides of hard metal or the transition metals oxides like oxides of copper, zinc, iron, and chromium do not dissolve in water due to their limited basicity. Alkaline earth metal oxides also form hydroxides in water but these hydroxides themselves give slaked solutions and are not completely soluble.
whats the phycical property of water
Answer:
The answer is color, temperature, turbidity, taste, and odor.
When calcium reacts with chlorine to form an ionic compound, each metal atom loses electron(s) and each nonmetal atom gains electron(s). there must be calcium atom(s) for every chlorine atom(s) in the reaction.
When calcium reacts with chlorine, each calcium atom loses 2 electrons, and each chlorine atom gains 2 electrons. There must be one 1 calcium atom for every 2 chlorine atoms in the reaction.
When atoms react, they either lose or gain electron. Atoms do this in order to attain the stable noble gas configuration. Metals are more likely to lose electrons, and non-metals are more likely to gain electrons. Calcium has an atomic number of 20, and its electronic configuration is:
[Ca] = 1s²2s²2p⁶3s²3p⁶4s²
The easiest way for calcium to obtain a stable noble gas configuration is to lose 2 of its electrons, so that it has 18 electrons left. When this happens, calcium becomes a positively charged cation:
Ca ⇒ Ca²⁺ + 2e⁻
Chlorine has 17 electrons with the electronic configuration:
[Cl] = 1s²2s²2p⁶3s²3p⁵
This shows that chlorine only needs one electron to have the stable noble gas configuration. When this happens, chlorine becomes a negatively charged anion:
Cl + 1e⁻ ⇒ Cl⁻
Thus, for calcium to completely react with chlorine, there must be two atoms of chlorine for each carbon atom. This is because calcium loses two electrons, and each chlorine atom only accepts one. Hence:
Ca²⁺ + 2CL⁻ ⇒ CaCl₂
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you have two test tubes. one test tube contains fe 3(aq) solution and the other test tube contains ni 2(aq). predict what will happen when naoh(aq) is added to both test tubes. if a reaction occurs, what is the new chemical formula?
The new chemical formula is [tex] Fe(OH)_{3}[/tex] or ferric hydroxide.
Ion [tex] {Fe}^{3 + } [/tex] will react with NaOH while [tex] {Ni}^{2 + } [/tex] will not. The chemical reaction is as follows -
Chemical reaction stating reaction between [tex] {Fe}^{3 + } [/tex] and NaOH.
[tex] {Fe}^{3 + } [/tex] + NaOH → [tex] Fe(OH)_{3}[/tex] + Na
In the reaction, [tex] {Fe}^{3 + } [/tex] represents ferric ions, NaOH is the chemical formula of sodium hydroxide, [tex] Fe(OH)_{3}[/tex] is the chemical formula of ferric hydroxide and Na represents sodium. The ferric hydroxide precipitates as reddish brown. It does not dissolve in excess is sodium hydroxide.
Chemical reaction stating reaction between [tex] {Ni}^{2 + } [/tex] and NaOH
Nickel does not react with sodium hydroxide due to its basic nature. The reason can be owed to electron donating characteristic of both the metal and base.
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7. This question is about calculating the area.
A nanoparticle is in the shape of a cuboid.
Calculate its surface area to volume ratio.
Show working.
a
a = 80 nm
b = 15mm
c = 20nm
C
Surface area to volume ratio:
Look at the two waves shown. What is the speed of each wave?
The speed of all electromagnetic waves is equal to the speed of light that is 3 × 10⁸ m/s.
What is an electromagnetic wave?An electromagnetic wave is a wave of certain wavelength of an electromagnetic radiation of the electromagnetic spectrum. There are different types of waves in the spectrum like IR, radio waves etc.
The speed of c of the wave is the product of its frequency and wavelength. The speed of all electromagnetic waves are equal to the speed of visible light.
Hence, the speed of both waves is 3 × 10⁸ m/s.
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1. Consider the generic reaction:A + 2BC AH = -55 kJDetermine the amount of heat emitted when each amountof reactant completely reacts (assume that there is morethan enough of the other reactant).(a) 1 mol A(b) 2 mol A(c) 1 mol B(d) 2 mol B
Answer:
(a) 55 kJ of heat are released when 1 mol of reactant A is used;
(b) 110 kJ of heat are released when 2 moles of reactant A are used;
(c) 27.5 kJ of heat are released when 1 mol of reactant B is used;
(d) 55 kJ of heat are released when 2 moles of reactant B are used.
Explanation:
The question requires us to determine the amount of heat released when the given amounts of reactants are used, considering the following balanced chemical equation:
[tex]A+2B\rightarrow C\text{ }\Delta H=-55kJ[/tex]When the enthalpy change for a reaction (or heat of reaction, ΔH) is given in units of energy, such as kilojoules (kJ), and not units of energy per mol (such as kJ/mol), we can consider that ΔH corresponds to the heat absorbed or released for the molar quantities of reactants as given in the balanced chemical equation. In the case given by the question, for example, we can say that 55 kJ of energy are released when 1 mol of A reacts with 2 moles of B.
Therefore, we can use the molar quantitites from the balanced chemical equation as a reference to determine the amount of heat released when different amounts of reactants are used.
Considering the information above, we can calculate:
(a) heat released when 1 mol of A reacts:
Note that 1 mol of A corresponds to the amount of reactant A given by the balanced chemical equation. Therefore, 55kJ of energy are released when 1 mol of A is used.
(b) heat released when 2 moles of A reacts:
Note that 2 moles of A corresponds to the double of the amount of reactant A given by the balanced chemical equation. Thus, we must multply ΔH by 2: 55 kJ x 2 = 110 kJ of energy are released when 2 moles of A are used.
(c) heat released when 1 mol of B reacts:
Note that 1 mol of B corresponds to half of the amount of reactant B given by the balanced chemical equation. Thus, we must divide ΔH by 2: 55 kJ / 2 = 27.5 kJ of energy are released when 1 mol of B is used.
(d) heat released when 2 moles of B reacts:
Note that 2 moles of B corresponds to the amount of reactant B as given by the balanced chemical equation. Therefore, 55 kJ of energy are released when 2 moles of B are used.
a 30.84 ml volume of 0.128 m naoh is required to reach the phenolpthalein endpoint in the titration of a 5.441 g sample of vinegar. calculate the percent acetic acid in the vinegar.
The percentage of acetic acid in vinegar is 4.36%
What is acetic acid?
The scientific name for acetic acid is ethanoic acid. It is an acidic, colorless liquid organic substance having the formula CH3COOH. Vinegar has a minimum of 4% acetic acid by volume, making acetic acid the primary component of vinegar besides water and trace elements.
Given,
Volume= 30.84 ml
Moles= 0.128
mass of vinegar= 5.441g
moles NaOH = 0.03084 ml x 0.128
M=0.00395
mass acetic acid = 0.00395 mol x 60.05 g/mol=0.237 g
Percentage of acetic acid:
= 0.237 x 100/ 5.441
= 23.7/5.441 = 4.36%
Hence, The percentage of acetic acid in vinegar is 4.36%
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why do you like homo and heterogen mixtures?
Homogeneous are hard to seperate but heterogeneous are easy to seperate.
What role does heterogeneous mixture have in daily life?Every day, humans employ heterogeneous mixes that can be found all around them. Particles in heterogeneous mixtures can be recognized after mixing and still maintain their chemical characteristics. Filtration and chemical processes can be used to separate the components of heterogeneous mixes.
All substances exist in one state of matter, which is a homogenous mixture. Solids can combine uniformly with other solids, liquids can combine with other liquids, and so on.
On the other hand, a heterogeneous mixture (derived from the Greek word "hetero" for dissimilar) has a non-uniform composition, which means that different parts may contain more or less of a given component. A heterogeneous mixture allows for the simultaneous existence of solid, liquid, and gas phases as well as other states of matter.
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Match the structural formulas given to you below with the correct chemical formula from the bank above. (Image provided)
1) C3H6O because there are 6 hydrogen in formula and one oxygen. 2) H2So4 sulphric acid.
What three categories exist for chemical formulas?Chemical formulas can be divided into three categories: empirical, molecular, and structural. Molecular formulas display the quantity of each type of atom in a molecule, while structural formulas display the simplest whole-number relationship between the atoms in a compound. Empirical formulas display the simplest whole-number relationship between the atoms in a compound.
3) C2H2 ethyne where carbons have triple bond.
4) CO carbon monoxide where C and O have triple bond between them .
5) HNO3 is nitric acid .
6) CH2F2
7) Ch2O
8) C2H4 is ethene in which carbon carbon have double bonds.
9) SO3 sulphur trioxide.
10) CH3F
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i am pouring concentrated sulfuric acid from a 1-gallon container. i need to use the following ppe for protection against potential splash of a corrosive liquid.
Personal protective equipments to be worn while handling corrosive liquids are safety goggles, hand gloves and closed toed shoes.
What are personal protective equipments ?Personal protective equipment is a protective clothing which is worn to protect the wearer's body from hazard or injury.The hazards which can be addressed by the use of personal protective equipment are physical,chemical and bio hazards.
It imposes a barrier between the user and the working environment.The main purpose of personal protective equipment is to reduce exposure of employees to the hazards.
It has a limitation that it does not eliminate the hazard and may lead to harm to the employee if the equipment is damaged.
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a student is running an experiment in which 42.0 grams of coso4 is needed, but the only jar of reagent in the lab is labelled cobalt(ii) sulfate hexahydrate. how many grams of the hydrate must the student weigh out in order to get the desired amount of the anhydrous compound?
A mass of 71.26g of [tex]CoSO_4.6H_2O[/tex] is required to get 42g of the anhydrous compound, i.e., [tex]CoSO_4[/tex].
A compound's molar mass indicates the mass of one mole of that substance. In other words, it informs you how many grams of a substance there are per mole. A covalent compound's formula mass is also known as its molecular mass. The mole is a useful quantity unit for representing very large quantities of atoms or molecules. A substance's molecular mass is the total of the atomic masses of all the atoms that comprise the molecule of the substance.
The term anhydrous means "without water." Anhydrous chemicals are compounds that do not contain water or do not contain water. An anhydrate is formed when water is removed from a hydrate. Suction or high-temperature heating of the chemical removes the water molecules. An anhydrous salt, for example, has had water driven out of its crystals.
Given:
Mass of [tex]CoSO_4[/tex] needed = 42g
To find:
Mass of [tex]CoSO_4.6H_2O[/tex] = ?
Formula:
Mass of [tex]CoSO_4.6H_2O[/tex] = (Mol. Wt. of [tex]CoSO_4.6H_2O[/tex] / Mol. Wt. of [tex]CoSO_4[/tex]) x Mass of [tex]CoSO_4[/tex]
Calculations:
Mol. Wt. of [tex]CoSO_4[/tex] = 155g/mol
Mol. Wt. of [tex]CoSO_4.6H_2O[/tex] = 155 + 6 x 18 = 263g/mol
Mass of [tex]CoSO_4.6H_2O[/tex] = (263 / 155) x 42
Mass of [tex]CoSO_4.6H_2O[/tex] = 71.26g
Result:
71.26g of [tex]CoSO_4.6H_2O[/tex] is required to get 42g of the anhydrous compound.
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an arctic weather balloon is filled with of helium gas inside a prep shed. the temperature inside the shed is . the balloon is then taken outside, where the temperature is . calculate the new volume of the balloon.
When the balloon is taken outside where the temperature is –9 °C, then the final volume becomes 19.3 L
From the question given above, the following data were obtained:
Initial volume (V₁) = 20.9 L
Initial temperature inside the shed (T₁) = 13 °C = 13 + 273 = 286 K
Final temperature inside the shed (T₂) = –9 °C = –9 + 273 = 264 K
As we know pressure remains constant so Pressure = constant
The final volume (V₂) =?
By using the Charles law equation, we can obtain the final volume i.e. V₂
[tex]\frac{V1}{T1}[/tex] = [tex]\frac{V2}{T2}[/tex]
[tex]\frac{20.9}{286}[/tex] = [tex]\frac{V2}{286}[/tex]
Now cross multiply both sides
V₂ × 286 = 20.9 × 264
V₂ × 286 = 5517.6
Divide by 286 on both sides of the equation
[tex]V_{2}[/tex] = [tex]\frac{5517.6}{286}[/tex]
V₂ = 19.3 L
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The complete question is:
An arctic weather balloon is filled with 20.9L of helium gas inside a prep shed. The temperature inside the shed is 13 degrees C. The balloon is then taken outside, where the temperature is -9 degrees C. Calculate the new volume of the balloon. You may assume the pressure on the balloon stays constant at exactly 1 atm. Round your answer to significant digits.
An atom of Gold contains 120 neutrons. What is its mass number?
Answer:
199
Explanation:
Au has atomic number of 79
so mass number = 79 + 120 = 199
What mass of HCI is needed to
generate 45.2 g of AICI3?
2AI + 6HCI → 2AlCl3 + 3H₂
AICI3: 133.33 g/mol
HCI: 36.46 g/mol
Answer:
37.1g of HCl
Explanation:
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1. using your titration data, calculate the %na2co3 for each trial, the average %na2co3 and standard deviation. 2. describe how to obtain a second derivative plot. 3. why is potentiometry used to detect the endpoints for this titration? could color indicators have been used?
Simply subtract the differences in the first derivative values from the differences in the midpoint volumes to obtain the second derivative, and then plot this value at the intersection of the two midpoint volumes.
Potentiometric titration is a laboratory method to determine the concentration of a given analyte.
Na2CO3 and NaHCO3 concentration in a mixture can be determined by accurately weighing 2.0 g of the mixture and making a distilled water solution in a 250 ml standard flask. Use phenolphthalein as an indicator while you gradually titrate 25 ml of this solution against regular hydrochloric acid. To concord, repeat (Vp ml).
In order to locate the equivalency more precisely, a second derivative plot is also generated. point—where the extrapolated line intersects the x-axis (graph 4). A highly precise value for the volume of titrant can be acquired because the x-axis indicates the volume of titrant utilized.
Potentiometric titration is one of the chemical methods of analysis, and it involves adding a titrant with a known concentration and measuring the endpoint of the titration with an indicator electrode that records the change in potential as a function of the amount (often the volume) added.
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cheggin the experiment to determine which mechanism was used by restriction endonucleases, what evidence ruled out the formation of a covalent intermediate?
The covalent phosphodiester bonds of DNA are hydrolyzed by restriction enzymes, leaving either "sticky/cohesive" ends or "blunt" ends.
By incubating the target DNA molecule with restriction enzymes, which detect and bind certain DNA sequences and cleave at specified nucleotides either inside or outside of the recognition sequence, restriction digestion is carried out.
An isolated bacterial protein known as a restriction enzyme cleaves DNA at sequence-specific locations to create DNA fragments with a known sequence at either end. Restrictions enzymes are crucial for numerous laboratory processes, including recombinant DNA technology and genetic engineering.
At the particular restriction site, DNA bonds between the 3′ OH of one nucleotide and the 5′ phosphate of the following one are cleaved by restriction enzymes.
In order to prevent the plasmid vector from ligating with itself and to verify that the inserted gene is oriented correctly, two separate restriction enzyme sites might be used.
A) #1 5′ - CGTGATCTCGATTCGCTAGTAACGTT - 3′
3′ - GCACTAGAGCTAAGCGATCATTGCAA - 5′
#2 5′ - TCATGAATTCCTGGAATCAGCAAATGCA - 3′
3′ - AGTACTTAAGGACCTTAGTCGTTTACGT - 5′
B) Recognition sites:
#1 5′ - GAATTC - 3′
3′ - CTTAAG - 5′
#2 5′ - GAATTC - 3′
3′ - CTTAAG - 5′
C) Cleavage sites:
#1 5′ - G AATTC - 3′
3′ - CTTAA G - 5′
#2 5′ - G AATTC - 3′
3′ - CTTAA G - 5′
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if the pressure is decreasing at a rate of 50 kg/m2, the temperature is increasing at a rate of 7.2 k/s, and the amount of gas (i.e., the number of moles) remains the same, what is the rate of change of the volume?
The rate of change of the volume is 0.144 m³/s.
The average temperature of the air is indicated via a properly exposed thermometer at some point in a given term, usually an afternoon, a month, or a yr. For climatological tables, the mean temperature is generally calculated for each month and for the 12 months. Temperature is an amount that determines the course of the float of warmth on preserving two bodies at one-of-a-kind temperatures in contact. Its SI unit is kelvin (k).
The heat of an object is the total power of all the molecular movement interior that object. Temperature is the measure of the thermal power or average warmness of the molecules in a substance. SI Unit. Joule.
rate of change of pressure = 50 kg/m²
temperature = 7.2 K/s
Using ideal gas equation PV = nRT
since nR is constant
V = T/P
= 7.2/50
= 0.144 m³
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A river flows at a rate of 57.3m/sec, what is the rate when it is converted to km/day? Please answer fast!!!
experimentally, it is found that 3.4 moles of a molecule in gaseous form requires the addition of 454 j of energy at constant volume in order to raise its temperature by 8.4 k. calculate the molar heat capacity at constant volume for this gas.
The molar heat capacity at a constant volume for this gas is 15.90 J/(K⋅mol) if 3.4 moles of this gas require 454 j of energy to raise its temperature by 8.4 k.
The molar heat capacity can be calculated by using the formula;
molar heat capacity = C / n
where C represents the heat capacity
n represents moles
The heat capacity of this gas can be calculated as follows;
heat capacity = E / T
here, E represents the amount of heat energy supplied
T represents the change in temperature
Substituting the given values in the heat capacity formula;
heat capacity = 454 / 8.4
heat capacity = 54.05
Now we substitute this calculated value of heat capacity in the formula of molar heat capacity;
molar heat capacity = C / n
molar heat capacity = 54.05 / 3.4
molar heat capacity = 15.90
Therefore, the molar heat capacity for this gas at constant volume is calculated to be 15.90 J/(K⋅mol).
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several properties of water are shown classify the ones that are phycical propertys
and the chemical propertys
Water's physical characteristics include its liquid state at ambient temperature and density of 1.0 g/cm3. Water has the ability to divide into hydrogen and oxygen and react with some metals, among other chemical features.
Phycical and Chemical PropertysA substance's physical property is a quality that can be seen or quantified without affecting the substance's identity. Color, density, hardness, and melting and boiling points are examples of physical qualities. The capacity of a substance to go through a particular chemical transition is described by its chemical property. An attribute of a specific material that can be seen in a chemical reaction is called a chemical property. Major chemical characteristics include chemical stability, flammability, toxicity, heat of combustion, pH value, and rates of radioactive decay.To learn more about Phycical and Chemical Propertys refer:
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why would air moving over a cold current cause fog (advection fog)? group of answer choices the cold current produces the fog when kelp beds release condensation nuclei. all of the other answers are correct, and thus this is the best answer the cold current produces the fog by mixing with the air. the air is chilled, which decreases the capacity of air to hold water vapor, and eve
The correct answer is option C.
The air moving over a cold current cause fog or advection fog when the air is chilled, which decreases the capacity of air to hold water vapor, and eventually, the relative humidity reaches 100% - leading to condensation and fog formation.
What is advection fog?
When warm- moist air or warm air front slides over the cold air front or cold surface, it results in the formation of advection fog.
Resultantly, the air becomes saturated and chilled at high humidity levels due to which water vapors start to condense leading to fog formation.
Moreover, the optimal condition for the formation of advection fog is cloudy windy weather having moderate to powerful winds.
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The complete question is:
Why would air move over a cold current cause fog (advection fog)?
(a) the cold current produces the fog when kelp beds release condensation nuclei.
(b) the cold current produces the fog by mixing with the air.
(c) the air is chilled, which decreases the capacity of air to hold water vapor, and eventually, the relative humidity reaches 100% - leading to condensation and fog formation.
the reaction 2a → a2 was experimentally determined to be second order with a rate constant, k, equal to 0.0265 m–1min–1. if the initial concentration of a was 3.75 m, what was the concentration of a (in m) after 180.0 min?
Based on the integrated equation used for reactant concentration calculation in a second-order reaction and the data given (initial concentration, reaction rate constant, and time elapsed), the concentration of A after 180.0 min will be 0.20 M.
The integrated equation for the reactant concentration in a second-order reaction looks like this:
1/[A] = kt + 1/[A]₀
k - reaction rate constant (0.0265 min⁻¹M⁻¹)
[A]₀ - initial concentration (3.75 M)
t - time elapsed (180.0 min)
1/[A] = 0.0265 min⁻¹M⁻¹ * 180.0 min + 1/(3.75 M) = 4.77 M⁻¹ + 0.27 M⁻¹ = 5.04 M⁻¹
[A] = 1 / (5.04 M⁻¹) = 0.20 M
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ELEMENT #3
The radius of my most common ion is larger than my atomic radius.
I have 6 valence electrons.
I have a higher first ionization energy than tellurium.
I am the smallest atom in my group.
What element am I? Write my symbol and standard electron configuration.
*dont have to give me the electron configuration i can find it
What is the lithosphere? ) (25 pts)
Someone help me with this please
A scientist sets up an experiment as follows: she puts bromine gas in a flask that is attached to an airless chamber. Describe what the scientist will observe when she opens the tap connecting the chamber to the flask. Explain your answer.
Answer:
The bromine gas particles would diffuse from a high to low concentration and so move upwards.
Explanation:
Maybe this is your answer ;{
Argon is one of the six noble gases, a group of elements that are known to be nonreactive. Explain why Noble Gases such as argon are nonreactive. Provide evidence from the model you drew in Question 1 to support your response.
The noble gases are known to be nonreactive because they have an already filled outer electron shell.
What are noble gases?The noble gases is defined as those elements that are located at the group 8 of the periodic table which are also called inert gases.
Examples of six noble gases include the following:
Helium (He), Neon (Ne),Argon (Ar),Krypton (Kr),Xenon (Xe), and Radon (Rn).The features of noble gases include the following:
They are odorless gases.They are non-flammable gases.Their melting and boiling points are close together giving them a very narrow liquid range.They are colourless gases. They are monoatomic gases with low chemical reactivity; andThe noble gases are called inert gases because they are non reactive gases.The noble gases are non reactive because the outer atomic shells of these gases are filled up that is to say that they have a full Valence electron shell.
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Why does H2O(s) floats on H20(l) when both are at 0c
H2O(s) floats on H2O(l) when both are at 0°c because ice is lighter than water which causes water to displace ice.
The density of a substance is calculated by the ratio of the mass of the substance to the volume of the substance.
Ice structure is cage like with more intermolecular spacing and Hydrogen bonds are stable. Water structure is linear and Hydrogen bonds form and reform. It causes more volume for same mass in ice and less volume for same mass in water.
At 0°C the density of ice is less than density of water. At 0°C, density of water is 1.0 gm/cm³ and density of ice is 0.931 gm/cm³, so water causes ice to displace resulting in ice floating over the water.
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A student measures 25ml of acid into the flask and adds the 3 drops of the indicator. if the student then adds 20ml of water to the flask, will this change to amount of base needed to reach the endpoint?
The addition of water to the acid solution will change the molarity of the solution, but not the amount of base needed to reach the titration endpoint because the total amount of acid hasn't changed.
During this titration, a solution of the base will be added to a solution of the acid, and when the endpoint is reached, the indicator will change color. The titration endpoint is reached when the acid in the sample solution has been completely neutralized, and an excess base is now appearing.
The amount of base required for neutralization is determined by the amount (number of moles) of acid in the starting solution. Although the starting solution would become more dilute (lowering its molarity) upon the addition of water, the total amount of acid will not be reduced, thus requiring the same amount of base.
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How many joules of heat are needed to change 50.0 grams of ice at -15.0 C to steam at 120.0 C
The answer is
153.7kJ.
The total energy needed for the water molecules to transition from ice to water and subsequently from water to vapor is what you are asked to calculate.
In order to do this, you'll need to know:
Heat of fusion of water: ΔHf = 334J/g;
Heat of fusion vaporization of water: ΔHv = 2257J/g;
Specific heat of ice: c = 2.09J/g∘C;
Specific heat of water: c = 4.18J/g∘C;
Specific heat of steam: c = 2.09J/g∘C;
So, the following steps describe the overall process:
1. Calculate the amount of heat needed to raise the ice's temperature from − 15.0∘C to 0∘C:
q1 = m ⋅ Cice ⋅ ΔT = 50.0g ⋅ 2.09J/g⋅∘C ⋅ (0∘C−(−15∘C)) = 1567.5J
2. Calculate the amount of heat needed to convert 0∘C ice to 0∘C water:
q2 = m⋅ ΔHf = 50.0g ⋅ 334J/g = 16700J
3. Calculate how much heat is needed to evaporate water at 0∘C to water at 100∘C:
q3 = m ⋅ Cwater ⋅ ΔT = 50.0g ⋅ 4.18J/g⋅∘C ⋅ (100∘C−0∘C) = 20900J
4. Calculate the amount of heat needed to convert 100∘C water to 100∘C vapor:
q4 = m ⋅ ΔHv = 50.0g ⋅ 2257J/g = 112850J
5. Identify the heat needed to transition from 100∘C vapor to 120∘C vapor:
q5 = m ⋅ Cvapor ⋅ ΔT = 50.0g ⋅ 2.09J/g⋅∘C ⋅ (120∘C−100∘C) = 2090J
Therefore, the total heat required is
qTOTAL = q1 + q2 + q3 + q4 + q5 = 152696.5J = 153.7kJ
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