Answer: true
Explanation:
Final answer:
The statement about serving hot tea in china tea cups is a cultural preference deeply rooted in Chinese history and the appreciation for fine porcelain from the Song dynasty, highlighting the importance of tradition in the enjoyment of tea.
Explanation:
The statement "Hot tea is best when served in china tea cups" touches upon aspects of culture, history, and personal preference rather than an objective truth. From the perspective of Chinese culture and history, true porcelain, invented in the Song dynasty, became a treasured export product.
The use of china tea cups is often associated with maintaining the temperature and enhancing the flavor of tea due to its thin walls and smooth surface. Additionally, Ceylon tea, known for its purity, along with the ritualistic and cultural aspects surrounding tea consumption, illustrate the historical significance and personal nature of tea drinking preferences. Therefore, the belief that hot tea is best served in china tea cups can be seen as a cultural preference rather than an absolute truth.
what are the 5 phases of matter?
Answer:solid
liquid
gas
supercritical fluid
plasma
superfluidity in liquid helium (that is Bose-Einstein condensate property)
supersolidity in fermionic condensate like the potassium40
Hope this helps and i like your profile pic ;)
The five phases of matter are solids, liquids, gases, plasma, and Bose-Einstein condensates.
Each phase differs in the way its atoms and molecules behave and interact with one another, resulting in different properties and behaviors.
Here's a brief explanation of each of the five phases of matter:
Solids: Solid matter has a definite shape and volume. It is rigid and cannot be compressed.
Liquids: Liquid matter has a definite volume but takes the shape of the container it's in. It can flow and be poured.
Gases: Gaseous matter has neither a definite shape nor a definite volume. It can be compressed and expanded.
Plasma: Plasma is a high-energy state of matter in which atoms lose their electrons, resulting in a mix of free electrons and positively charged ions. It is the most common state of matter in the universe.
Bose-Einstein Condensates: Bose-Einstein condensates are formed at extremely low temperatures when a group of atoms behaves like a single entity, becoming indistinguishable from one another.
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Do valence electrons show a repeating or periodic pattern? Explain.
Answer:
Yes, valence electrons show a repeating or periodic pattern.Explanation:
It is precisely the repeating pattern of the valence electrons which is the responsible for the repeating pattern of the chemical properties: elements on a same group (column) of the periodic table have similar chemical properties because they have the same number of valence electrons.
The chemical changes (reactions) are the result of the interaction of the electrons of the elements, and, since the valence electrons are the outer most electrons, you can expect that it is the valence electrons which most influence the occurrence of the chemical reactions, which is what defines the chemical properties.
Here you have the pattern of the valence electrons shown by the representative elements on the periodic table:
Group number number of valence electrons
(column number)
1 1
2 2
13 3 (the ones digit of the column number)
14 4 (the ones digit of the column number)
15 5 (the ones digit of the column number)
16 6 (the ones digit of the column number)
17 7 (the ones digit of the column number)
18 8 (the ones digit of the column number)
An electrolytic cell is based upon a nonspontaneous reaction; the Eocell for the reaction is _____.
greater than one
less than zero
equal to one
equal to zero
In an electrochemical cell in which the oxidation reaction is nonspontaneous the oxidation will not occur spontaneously at the anode and the reduction will not be spontaneous at the cathode. And according to the law for the calculation of the voltage potential of the electrochemical cell (Ecell):
Ecell = Eox. - Ere. where (Eox. is the potential of the oxidation at the anode and Ere. is the potential of the reduction at the cathode). The standard potential for an electrolytic cell is negative, because of the Ere. which is greater than Eox.
The answer is : less than zero.
An experiment with 55 co takes 47.5 hours. at the end of the experiment, 1.90 ng of 55-co remains. if the half-life is 18.0 hours, how many ng of 55-co were originally present?
Answer:
[tex]\boxed{\text{10.7 ng}}[/tex]
Explanation:
Let A₀ = the original amount of ⁵⁵Co .
The amount remaining after one half-life is ½A₀.
After two half-lives, the amount remaining is ½ ×½A₀ = (½)²A₀.
After three half-lives, the amount remaining is ½ ×(½)²A₀ = (½)³A₀.
The general formula for the amount remaining is:
A =A₀(½)ⁿ
where n is the number of half-lives
n = t/t_½
Data:
A = 1.90 ng
t = 45 h
t_½ = 18.0 h
Calculation:
(a) Calculate n
n = 45/18.0 = 2.5
(b) Calculate A
1.90 = A₀ × (½)^2.5
1.90 = A₀ × 0.178
A₀ = 1.90/0.178 = 10.7 ng
The original mass of ⁵⁵Co was [tex]\boxed{\text{10.7 ng}}[/tex].
Because the the individual components of any mixture are not _____ to each other, the composition of those components can vary. Also, some of the _____ properties of the individual components are still noticeable
Answer:
Because the individual components of any mixture are not bonded to each other, the composition of those components can vary. Also, some of the physical properties of the individual components are still noticeable.
Explanation:
A mixture is a combination of two or more pure substances that are present in any proportion and each pure substance keeps its own physical and chemical properties.
As oppossite to mixtures, the compounds are pure substances formed by two or more different elements which are chemically bonded to each other. So, while in the compounds the components (elements) are bonded in a fixed proportion, and their composition cannot vary, in the mixtures each component may be present in any proportion, which means that the composition can vary.
Take, for example, the simple case of talc and iron particles.This is a mixture. Talc is not bonded to the iron particles, and so their proportion, the compositoin, can vary in any form. Aslo, both talc and iron particles keep their own physical properties: you can perfectly separate the mixture by using a magnet to attract the iron particles, because they have not lost their magnetic property (a physical one).
Explain why the pbcl2 dissolved when water was added
PbCl2 would not dissolve because it is insoluble based on the solubility rules for substances that will dissolve in water. This compound would instead form a solid precipitate at the bottom of the container.
PbCl2 dissolves in water as it dissociates into Pb²+ and Cl¯ ions which attract polar water molecules. Just like potassium chloride, lead(II) chloride dissolves due to hydration of ions. Solubility of PbCl2 may increase with temperature.
Explanation:When PbCl2 is dissolved in water, it dissociates into ions Pb²+ and Cl¯. These ions interact with water molecules due to the presence of polar bonds in water. Just like potassium chloride (KCl) dissolves in water by getting hydrated, or attracting water molecules, lead(II) chloride (PbCl2) dissolves in a similar fashion. Water, being a polar molecule, is attracted by the charges on both lead(II) and chloride ions. This hydration of ions is an important factor in the dissolution of many solids into liquids.
Moreover, the solubility of various solids in water tends to increase with temperature. Hence, if the PbCl2 was added to warm water, it might have increased its solubility, enabling more of PbCl2 to dissolve.
However, it is important to note that certain compounds like PbCl2 have relatively low solubility in water, and may still leave some solid undissolved even after thoroughly mixing.
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The atomic mass of carbon is 12.01, sodium is 22.99, and oxygen is 16.00. What is the molar mass of sodium oxalate (Na2C2O4)?
Answer:
134g/mol
Explanation:
When a solvent can dissolve no more of a solid solute at a specific temperature, we say the solution is______
The answer is Saturated
The solute is saturated when it can no longer absorb any more of a substance.
3 A2 + B2 >>> 2 units of product
3 AA + BB >>> 2 products
3 volumes + 1 volume >>> 2 volumes product
3 liters + 1 liter >>> 2 liters product
3 moles A2 + 1 mole B2 >>> 2 moles product
Click to get the correct formula for the product of the reaction.
options:
AB2
A2B
A3B
AB
Answer:
A₃B.
Explanation:
3 AA + BB → 2 products.
Any chemical reaction should obey the law of conservation of mass that the no. of reactants atoms is equal to the no. of products atoms.Herein, 6 atoms of A react with 2 atoms of B.So, the product should contain 6 atoms of A and 2 atoms of B.The reaction produces 2 units of the product, so the product unit must contain 3 atoms of A and 1 atom of B.Thus, the product unit is A₃B.The reaction is:
3AA + BB → 2A₃B.
Explain why aldehydes and ketones react with a weak acid such as hydrogen cyanide but do not react with strong acids such as hcl or h2so4 (other than being protonated by them).
Answer:
The cyanide ion is a strong nucleophile.
Explanation:
Strong acids
Strong acids like hydrochloric and sulfuric acid dissociate completely in solution.
[tex]\underbrace{\hbox{HCl }}_{\hbox{strong acid}} + {\text{ H$_{2}$O }} \longrightarrow \text{H}_{3}\text{O}^{+}+ \underbrace{\hbox{Cl^{-}}}_{\hbox{weak nucleophile}}[/tex]
Because they are strong acids, their conjugate bases are extremely weak bases/nucleophiles.
Thus, they can protonate the carbonyl oxygen, but the conjugate bases cannot act as nucleophiles.
Weak acids
Weak acids like HCN dissociate only slightly in solution.
[tex]\underbrace{\hbox{HCN}}_{\hbox{weak acid}} + {\text{ H$_{2}$O }} \rightleftharpoons \text{H}_{3}\text{O}^{+}+ \underbrace{\hbox{:CN^{-}}}_{\hbox{strong nucleophile}}[/tex]
Because HCN is a weak acid, its conjugate base is a strong nucleophile.
Thus, it generates relatively few hydronium ions, but the cyanide ion is a strong nucleophile that can attack the partially positive carbon and form the cyanohydrin.
RCH=O + CN⁻ ⟶ RCH(CN)O⁻ ⟶ RCH(CN)OH
As the CN⁻ ions react with the aldehyde or ketone, they are removed from solution.
According to Le Châtelier's Principle, more HCN dissociates to replace the CN⁻ ions, and the reaction goes nearly to completion.
Aldehydes and ketones react with hydrogen cyanide because it provides cyanide ions that act as nucleophiles in a nucleophilic addition reaction to form cyanohydrins; strong acids don't provide such nucleophiles and instead only protonate the carbonyl group.
Explanation:The reason why aldehydes and ketones react with a weak acid like hydrogen cyanide (HCN) but not with strong acids such as HCl or H2SO4 lies in the mechanism of nucleophilic addition reactions. In the presence of a strong acid, the carbonyl group of aldehydes or ketones is protonated, making the carbon even more electrophilic but without providing a good nucleophile. HCN, being a weak acid, partially dissociates in the presence of a strong base to form cyanide ions (CN-), which are good nucleophiles and can attack the carbonyl carbon to form cyanohydrins. The reaction requires slightly acidic conditions (pH around 4-5) to optimize the rate, as too much strong acid would suppress the producing of cyanide ions necessary for the nucleophilic addition.
Aldehydes and ketones react with weak acids like hydrogen cyanide (HCN) because they can form cyanohydrins through nucleophilic addition reactions. In this reaction, the weak acid HCN is converted into the cyanide ion (CN-) by a small amount of a strong base. The cyanide ion then attacks the carbonyl carbon of the aldehyde or ketone, resulting in the formation of a cyanohydrin. This reaction requires a basic catalyst and is favored for aldehydes and unhindered ketones.
The table shows the characteristics of four substances after they are placed in water.
Substance
Ion concentration
Electrical conductivity
W
Medium
Good
X
Low
Poor
Y
High
Excellent
Z
None
None
Which compound is most likely the strongest electrolyte?
W
X
Y
Z
Answer:
Electrolytes are chemicals that break into ions (ionize) when they are dissolved in water. The positively-charged ions are called cations, while the negatively charged ions are called anions.
Strong electrolytes completely ionize in water. This means 100% of the dissolved chemical breaks into cations and anions.
Weak electrolytes partially ionize in water. Pretty much any dissociation into ions between 0% and 100% makes a chemical a weak electrolyte, but in practice, around 1% to 10% of a weak electrolyte breaks into ions.
If a substance doesn’t ionize in water at all, it’s a nonelectrolyte.
Explanation:
The substance that serves as a good electrolyte in the list is the substance labelled Y.
What is an electrolyte?An electrolyte is a solution that conducts electricity by the movement of ions in the solution. The high concentration of ions in the electrolyte implies that it has a good conductivity
Hence, the substance that serves as a good electrolyte in the list is the substance labelled Y.
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Arrhenius theorized that a base is a chemical compound that
Answer:
Arrhenius theorized that a base is a chemical compound that contains hydroxide ions (OH⁻) and ionizes in water releasing them.
Explanation:
Svante Arrhenius was the first scientist to theorize about acids and bases.
Arrhenius' acid base theory states that an acid is a compound that contains hydrogen atoms and ionizes in water to produce hydrogen ions (H⁺), and a base is a compound that contains hydroxide ions (OH⁻) that are released in water.
These are some examples of compounds which can be named as acid or base following Arrhenius' theory:
HCl: is an acid because it ionizes in water producing H⁺.H₂SO₄: is an acid because it ionizes in water producing H⁺NaOH: is a base because it ionizes in water producing OH⁻Ba(OH)₂: is a base because it ionizes in water producing OH⁻This theory is limited because it does not include compounds that do not contain or ionizes producting H⁺ or OH⁻. E.g. NH₃, which is a base (according to other theory).
Arrhenius theorized that a base is a chemical compound that dissolves in water to yield hydroxide anions (OH-) or absorbs hydrogen ions (H+) in a solution, thereby reducing acidity. The strength of a base depends on how readily it releases its hydroxide ions or absorbs hydrogen ions. Stronger bases release more hydroxide ions leading to higher pH.
Explanation:According to Arrhenius's theory, a base is a chemical compound that dissolves in water to yield hydroxide anions (OH-). For example, bases like ammonia can chemically react with water and release hydroxide ions in solution. Besides, a base can also absorb hydrogen ions (H+), present in the solution, resulting in reduced acidity.
The strength of a base is measured by how readily it releases its hydroxide ions or absorbs hydrogen ions. For instance, strong bases liberate most or all of their hydroxide ions, whereas weak bases release only some hydroxide ions or absorb only a few hydrogen ions.
These bases, such as bicarbonate (HCO3-), can form water molecules by combining with the H+ ions in a solution, thereby reducing the solution's acidity and raising the pH. On the other hand, stronger bases like Sodium hydroxide tend to readily donate OH-, leading to higher pH.
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Corrosion is the process by which iron is oxidized by elemental oxygen. therefore oxygen is the (oxidizing / reducing) agent and (gives / accepts) electrons.
Answer:
Oxygen is the oxidizing agent and accept electrons
Explanation:
Corrosion is an example of a redox reaction which involves both reduction and oxidation process.During corrosion a metal loses electrons and becomes oxidized to form a metal ion. Therefore, oxygen is the oxidizing agent since it undergoes reduction by gaining electrons.Therefore, during corrosion of iron, iron is the reducing agent and gives electrons, while oxygen is the oxidizing agent and accepts the electrons.2Fe(s) + O2(g) → 2FeO(s)
To which category does this reaction belong?
Answer:
Redox reactions
Explanation:
Redox reactions consists of both oxidation and reduction
one species gets oxidised and other species become reduced, both oxidation and reduction happen simultaneously
reduction is either gain of electrons or gain of hydrogen. in reduction the oxidation number of species reduces
in this reaction the reduction half equation is
O₂ + 4e --> 2O²⁻
oxidation is either loss of electrons or gain of oxygen. in oxidation the oxidation number of species increases.
Fe --> Fe²⁺ + 2e
since both these half reactions happen overall its a redox reaction
Which element is in both graphite and diamond?
Helium
Carbon
Nitrogen
Lithium
Answer:
Carbon
.. Both graphite snd diamond are carbon containing elements
Carbon is present in both diamond and graphite.
Explanation:The allotropes of carbon are called as Graphite and diamond. These minerals synthetically comprise of carbon molecules with various physical properties. These minerals, when all in options, are referred to be as polymorphs, having a similar kind of science, however of the different crystalline structures.
In these allotropes of carbon, the molecules comprising of carbon atoms in that of the Diamond and Graphite, are bound together by solid covalent bonds with various courses of action.
Valuable stone and graphite have move structures which speak to their assorted properties, and both are unadulterated carbon. In any case, the graphite's particles join to the three atoms of carbon and get related with the plates that are parallel to one another. The particles of Diamond enter the four atoms of carbon in an outline.
What volume of 0.125 m kmno4 is required to yield 0.180 mol of potassium permanganate
Answer:
= 1.44 L
Explanation:
Molarity or concentration is given by the formula;
Molarity = moles/volume in L
Therefore;
Volume = moles/molarity
Number of moles = 0.180 moles
Molarity = 0.125 M
Thus;
Volume = 0.18 mol/ 0.125 M
= 1.44 L
= 1.44 L
Methane reacts with oxygen to produce carbon dioxide water and heat.how many kcal are produced when 5.00 g of methane react
Answer:
= 66.33 kCal
Explanation:
The combustion of methane is given by the equation;
CH4(g) + 2O2(g) → CO2(g) + 2H2O(l); ΔH = -890.3 kJ/mol
The molar enthalpy of combustion of methane is -890.3 kJ/mol
This means 1 mole of CH4 yields 890.3 kJ/Mol
But, molar mass of methane is 16.04 g/mol
Therefore;
Heat produced by 5.0 g of methane will be;
= (5.0 g/ 16.04 g/mol)× 890.3 kJ/mol
= 277.525 kJ/mol
But; 1 kcal = 4.184 kJ
thus; = 277.525 /4.184
= 66.33 kCal
Final answer:
To determine the amount of heat produced when 5.00 g of methane reacts with oxygen, convert the given heat production for 2.50 g of methane to kcal, find the heat value per gram, and then multiply by the mass of methane used (5.00 g).
Explanation:
The question asks how many kilocalories are produced when 5.00g of methane (CH₄) is reacted with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O) and release heat. To find this, we can use the information provided: the combustion of 2.50 g of methane produces 125 kJ of heat. As 1 kcal is equivalent to 4.184 kJ, we can first convert 125 kJ of heat to kcal, which gives us 29.8 kcal (125 kJ / 4.184 kJ/kcal).
Since this amount of heat is produced by 2.50 g of methane, we can find the heat produced by 1 g by dividing 29.8 kcal by 2.5, which gives us 11.92 kcal/g. For 5.00g of methane, the heat produced would be 5 times 11.92 kcal/g, equating to 59.6 kcal.
The anions formed from the atoms of the elements in family VIA should carry a +6 charge.
a. true
b. false
The answer would be true
Final answer:
The statement is false because elements in family VIA (Group 16) of the periodic table typically form anions with a -2 charge, not a +6 charge, as they tend to gain two electrons to achieve a noble gas electron configuration.
Explanation:
The statement that the anions formed from the atoms of the elements in family VIA should carry a +6 charge is false. Elements in Group 16 (family VIA) of the periodic table, also known as the chalcogens, include oxygen, sulfur, selenium, tellurium, and polonium. These elements typically have six valence electrons and tend to gain two electrons to achieve a stable electron configuration, similar to that of a noble gas. As a result, these elements form anions with a -2 charge, not a +6 charge.
An easy way to remember the typical charge of anions in this group is by considering the general trend on the periodic table: as you move from the right to the left, elements form anions with a negative charge equal to the number of groups moved left from the noble gases. Therefore, since Group 16 is two groups left of the noble gases, the typical anion charge for these elements would be 2-.
How is radiation absorbed?
a. by increasing the molecular vibrations of molecules
b. by converting atoms to ions
c. by breaking chemical bonds
d. all of the above
By increasing the molecular vibrations
atoms change their chemical identity as the number of protons in their nuclei change.
A. Nuclear Fission
B. Both
C. Nuclear Fusion
Answer:
B
Explanation:
what is the total number of moles represented by 20 grams of CACO3
A. 0.1
B. 0.2
C. 1
D. 2
Answer:
B. 0.2.
Explanation:
We can use the relation:n = mass/molar mass
mass of CaCO₃ = 20 g, molar mass of CaCO₃ = 100.0869 g/mol.
∴ n = mass/molar mass = (20 g)/(100.0869 g/mol) = 0.1998 ≅ 0.2 mol.
So, the right choice is: B. 0.2.
Final answer:
To find the total number of moles in 20 grams of CaCO₃, calculate the molar mass of CaCO₃ and then use the formula for moles. The total number of moles in 20 grams of CaCO₃ is 0.2.
Explanation:
To calculate the total number of moles represented by 20 grams of CaCO₃, we first need to determine the molar mass of CaCO₃.
The molar mass of CaCO₃:
Ca: 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Adding these up gives a total molar mass of CaCO₃ as 100.09 g/mol.
Now, we use the formula:
Number of moles = Mass / Molar mass
Number of moles = 20 g / 100.09 g/mol = 0.2 moles
Therefore, 20 grams of CaCO₃ represents 0.2 moles.
Three identical flasks contain three different gases at standard temperature and pressure. flask a contains c2h6, flask b contains o3, and flask c contains nh3. which flask contains the largest number of molecules?
Answer:
All the three flasks contain the same number of molecules.Explanation:
According to Avogadro's principle, equal volume of gases at the same temperature and pressure will contain the same number of particles (atoms or molecules).
Therefore, being the three flasks identical, which includes that they have the same volumen, and being that they contain different gases at standard temperature and pressure, regardless of the chemical formula of each gas, by direct use of Avogadro's principle, they all will contain the same number of molecules.
The ideal gas equation, pV = nRT reflects this fact: if you isolate the ratio V/n, you get V/n = RT/p. Then, since RT/p (the right side) is constant, V/n is also constant, meaning that for a fixed volume the number of particles is constant, regardelss of the gas.
According to Avogadro's law, equal volumes of gas at the same temperature and pressure contain the same number of molecules. Therefore, all three flasks, despite containing different gases, would have the same number of molecules.
Explanation:The subject of your question pertains to the principles of chemistry, specifically related to Avogadro's law. According to Avogadro's law, equal volumes of different gases at the same temperature and pressure contain an equal number of molecules. Therefore, Flasks A, B, and C which contain C2H6, O3, and NH3 respectively, all at standard temperature and pressure, would each contain the same number of molecules. This principle applies regardless of the identity of the gas, as it is related to the behaviour of gases as outlined in the ideal gas law.
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which of the following correctly represents an ion pair and the ionic compound the ions form
a. Ca2-, F-, CaF2
b.Na+, Cl-, NaCl2
c. Ba2+, O2-, Ba2O2
d. Pb4+, O2-, Pb2O4
Answer:
It's a.
Explanation:
That would be Ca2+ , F- . We see in the compound CaF2 the signs balance to give a neutral compound, 2+ balances with 2-.
Answer: a. [tex]Ca^{2+}[/tex], [tex]F^-[/tex], [tex]CaF_2[/tex]
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
(a) calcium and fluorine: Here calcium is having an oxidation state of +2 called as [tex]Ca^{2+}[/tex] cation and fluorine [tex]F^{-}[/tex] is an anion with oxidation state of -1. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]CaF_2[/tex]. called as calcium fluoride.
(b) sodium and chlorine: Here sodium is having an oxidation state of +1 called as [tex]Na^{+}[/tex] cation and chlorine [tex]Cl^{-}[/tex] is an anion with oxidation state of -1. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]NaCl[/tex] called as sodium chloride.
(c) barium and oxygen : Here barium is having an oxidation state of +2 called as [tex]Ba^{2+}[/tex] cation and oxygen [tex]O^{2-}[/tex] is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]BaO[/tex] called as barium oxide.
(d) lead and oxygen : Here lead is having an oxidation state of +4 called as [tex]Pb^{4+}[/tex] cation and oxygen [tex]O^{2-}[/tex] is an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral [tex]PbO_2[/tex] called as lead(IV) oxide.
The requirement that a reversible reaction be at equilibrium is that:
A,the concentrations on the two sides of the arrow be equal
B.the velocity for the forward reaction equal that of the reverse reaction
C.there will be as many molecules of the substances on one side of the arrow as
there are molecules of the substances on the other side
D.the moles of products will equal the moles of reactants
Answer:
B.the velocity for the forward reaction equal that of the reverse reaction
Explanation:
A state of rest or motion of a system is described as equilibrium.
For a system to be in equilibrium, the following conditions must be met:
1. It must be involved in reversible chemical process no matter how small the extent of the reversibility.
2. The rate of forward process is equal to the rate of backward or reverse process.
3. The system must be closed.
4. There is no change in the concentration of each of the species in equilibrium with respect to time. There must be a constancy of concentration of each species in the equilibrium process.
When we change any of the conditions of equilibrium, the Le Chatelier's principle comes into play.
The principle states that "if any of the conditions of a system in equilibrium is changed, the system will adjust itself in order to annul the effect of the change".
Answer:
B.the velocity for the forward reaction equal that of the reverse reaction
Explanation:
A reversible reaction proceeds in a closed system. Equilibrium is only attainable in a closed system. When a reaction occurring in a closed system attains equilibrium, the rate(velocity) of the forward reaction will be exactly the same as the rate (velocity) of the reverse reaction.
This implies that the forward and reverse reactions proceed at the same rate.
In the reaction of chlorine with calcium, explain which atom is oxidized.
Show ALL steps and work. I don't understand this.
Answer:
The atom is oxidized is Ca.
Explanation:
The oxidation-reduction reaction contains a reductant and an oxidant (oxidizing agent).The oxidation process is the process in which electrons are lost and produce positively charged ions.The reduction process is the process in which electrons is gained and negatively charge ions are produced.In the reaction of chlorine with calcium:Ca + Cl₂ → CaCl₂,
Ca loses 2 electrons and is oxidized to Ca²⁺. (Ca → Ca²⁺ + 2e).
Cl is gains 2 electrons in "Cl₂, oxidation state zero" and is reduced to Cl⁻. (Cl₂ + 2e → 2Cl⁻).
What type of reaction is created by starting a fire by igniting gasoline?
A physical reaction
A chemical reaction
A combustion reaction
An oxidation reaction
Answer:
Oxidation reaction
Explanation:
When flame comes in contact with gasoline in the presence of oxygen, combustion takes place. Oxidation reaction involves reacting oxygen with a compound. To stop fire, we can stop the oxidation process by adding carbon (iv) oxide since it does not support combustion. Hence the reason why CO2 is used to stop flames.
Which grouping identifies chemical properties?A. Density, luster, boiling point B. Melting point, hardness, conductivity C. Malleability, ductility, texture D. Combustibility, flammability, reactivity
Answer:
option D. Combustibility, flammability, reactivity.Explanation:
Physical properties: characteristics of the matter that can be observed and measured by physical media, withoud changing the composition of the matter.
Typical examples of physical properties are: mass, volume, density, boiling point, melting point, hardness, specific heat.
Chemical properties: they are ability of the matter to change by decompositon or combination with other substances to produce one or more different substances. They cannot not be observed or measured without changing the composition of the orignal sample.Typical examples of chemical properties are reactivity with oxygen, reactivity with water, and any reactitivy in general.
Hence, applying those definitions to the set of choices you get:
A. Density, luster, boiling point (incorrect)
All of them are physical properties since they are observable and measurable without altering the composition of the sample.
B. Melting point, hardness, conductivity (incorrect)
They all are also physical properties. For example, melting point can be measured with a thermometer during the phase change.
C. Malleability, ductility, texture (incorrect)
Again, all physical properties. Ducitlity, for example, is the ability of the metals to form this wires.
D. Combustibility, flammability, reactivity (correct answer)
Combustibility: is the reaction with oxigen to form CO₂ and H₂OFlammability: is the ability to burn in flames, which is a chemical change.Reactivity: Already discussed.All these properties can only be measured by producing the correspondant chemical reaction (change), so they are chemical properties.
Answer:
The correct option is D
Explanation:
If force is held constant as surface area decreases pressure
Pressure, defined as the normal force per unit area, increases when the surface area decreases while the force is constant. This is based on the equation of pressure (P=F/A) and can be largely observed in fluid dynamics, for instance, within conduits with decreasing cross-sectional areas.
Explanation:Pressure is defined as the normal force per unit area exerted on a surface by a fluid or gas, or the force exerted perpendicularly on a surface. An important characteristic of pressure is that it acts uniformly in all directions at a single point in a fluid. This is also known as Pascal's Principle.
According to the equation P=F/A, where P is pressure, F is the force, and A is the area, pressure increases when surface area decreases, given that the force is held constant. This is simply because as the denominator in a fraction decreases, the overall value of the fraction increases. Therefore, if the surface area decreases with a constant force, the pressure consequently increases.
The phenomenon can be observed largely in fluid dynamics. For example, in pipes or any other fluid-carrying conduits where the cross-sectional area decreases, the pressure tends to increase due to the conservation of the flow rate (continuity equation). When the tube narrows, fluid speed increases and pressure decreases. Similarly, a decrease in the area of a compressed gas container while keeping the force (temperature) constant results in the compression of gases, thereby increasing their pressure.
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In an electrolytic cell, is it a oxidation-reduction reaction? True or False.
Answer:
\boxed{\text{True}}
Explanation:
Consider the electrolysis of molten MgCl₂.
During electrolysis
Mg²⁺ gains electrons, so it is reduced. Cl⁻ loses electrons, so it is oxidized[tex]\rm Reduction: Mg^{2+} + 2e^{-} \longrightarrow Mg\\Oxidation: 2Cl^{-} \longrightarrow Cl_{2} + 2e^{-}\\Overall: MgCl_{2} \longrightarrow Mg + Cl_{2}\\\\\text{Electrolysis is a }\boxed{\textbf{redox reaction}}[/tex]
A photon with a wavelength of less than 50.4 nm can ionize a helium atom.
What is the ionization potential of helium?
Answer in J
To find the ionization potential of an atom, you use the wavelength of light that causes the matter to ionize. This can be calculated using the Planck-Einstein relation where energy equals Planck's constant multiplied by light's frequency. Frequency is found using the speed of light equation which is then used in the Planck-Einstein equation to find the ionization potential.
Explanation:The question is asking for the ionization potential of a helium atom. Ionization potentials denote the energy required to remove an electron from an atom. It's given that the minimum wavelength of light that can ionize helium is 50.4 nm. The energy of a photon of light can be calculated using the Planck-Einstein relation, E=hν, where h is Planck's constant (6.626 x 10-34 Js) and ν is the frequency of the light. The frequency can be found from the speed of light equation, c=λν, rearranged to give ν=c/λ.
Substituting constants and the given wavelength, and converting m to nm:
ν = (3.00 x 108 m/s) / (50.4 x 10-9 m)
Therefore, E = (6.626 x 10-34 Js) x ν
This would yield the energy needed to ionize the helium atom and that value is the ionization potential of helium in Joules.
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