Answer:
The number and the kinds of atoms in the compound
Explanation:
A chemical formula of a compound contains symbols o the atoms of the elements present in the compound as well as the number of atoms of each element in the form of subscripts.Therefore it helps us to know the elements in a compound and the number of atoms in the compounds.Using the concentration of the base and the volume of the base used, calculate the moles of the base used in the titration. Then, using the mass of the acid, determine the molar mass of the acid.
Data:
Concentration of the Base(NaOH)= 0.19 M
Volume of the Base used= 8.72 mL
Mass of the Acid(unknown)= 0.33 g
Answer:
[tex]\boxed{\text{(a) 0.001 66 mol MOH; (b) 200 g/mol}}[/tex]
Explanation:
I am assuming that the unknown acid is monobasic. Then the general equation for the reaction is
HA + MOH ⟶ MA + H₂O
(a) Moles of MOH
[tex]\text{Moles of MOH}= \text{0.008 72 L MOH} \times \dfrac{\text{0.19 mol MOH}}{\text{1 L MOH}} = \text{0.001 66 mol MOH}[/tex]
(b) Moles of HA
Now, you use the molar ratio from the balanced chemical equation to find the moles of unknown acid.
[tex]\text{Moles of HA = 0.001 66 mol MOH} \times \dfrac {\text{1 mol HA}}{\text{1 mol MOH }} = \text{0.001 66 mol HA}[/tex]
(c) Molar mass of HA
[tex]\text{MM} =\dfrac{\text{mass}}{\text{moles}}= \dfrac{\text{0.33 g}}{\text{0.001 66 mol}} = \text{200 g/mol}[/tex]
The molar mass of the unknown acid is [tex]\boxed{\textbf{200 g/mol}}[/tex]
What is true of acids?
a.They are poor electrolytes.
b.They have a pH above 9.
c.They have a pH below 7.
d.They have a strong affinity for H ions.
Acids have a pH below 7 (option c), indicating a higher concentration of hydronium ions.
The correct answer is: c. They have a pH below 7.
In chemistry, acids are substances that have a pH value lower than 7. This lower pH indicates a higher concentration of hydronium ions (H₃O⁺) compared to pure water. For example, vinegar, which tastes sour, is an acid with a pH lower than 7. Strong acids are particularly notable for being able to damage materials, demonstrating their high acidity.
Here's why the other options are incorrect:
a. They are poor electrolytes.: Acids are actually good electrolytes, meaning they can conduct electricity in a solution. This is because they dissociate into ions, such as H+ and anions, which can carry electrical charge.b. They have a pH above 9.: This is actually characteristic of bases, not acids. Bases have a pH above 7, with a higher pH indicating a stronger base.d. They have a strong affinity for H ions.: This statement is somewhat misleading. Acids do release H+ ions, but they don't have a strong affinity for them. Instead, acids tend to donate H+ ions, increasing their concentration in a solution.what is the percent composition of iron in FeCl3
Final answer:
The percent composition of iron in FeCl3 is 34.43%.
Explanation:
The percent composition of iron in FeCl3 can be calculated by dividing the mass of iron by the molar mass of FeCl3 and multiplying by 100%. FeCl3 consists of one iron atom and three chlorine atoms. The atomic mass of iron is 55.845 g/mol and the atomic mass of chlorine is 35.453 g/mol. Therefore, the molar mass of FeCl3 is 55.845 g/mol + 3 * 35.453 g/mol = 162.204 g/mol. The mass of iron in FeCl3 is 55.845 g/mol / 162.204 g/mol * 100% = 34.43%.
Consider the following reaction:
iron (s) + chlorine (g) à iron (III) chloride
a. Write the balanced chemical equation.
b. 25.0 g of iron reacts with excess chlorine gas.
a. Calculate the moles of iron reactant.
b. Calculate the moles of iron (III) chloride.
c. Calculate the mass of iron (III) chloride.
Answer:
Explanation:
Fe + Cl₂ → FeCl₃
a. The balanced equation
All chemical equations obey the law of conservation of matter. To balance this above equation, we either inspect or use mathematical method to obtain a balanced equation.
We put coefficients a, b and c at the back of the compounds as shown below:
aFe + bCl₂ → cFeCl₃
For Fe:
a = c (i)
For Cl:
2b = 3c (ii)
let a = 1, c= 1
Solving for the unknown b, we have:
b = [tex]\frac{3c}{2}[/tex]
b = [tex]\frac{3}{2}[/tex]
The complete reaction equation is therefore:
Fe + [tex]\frac{3}{2}[/tex]Cl₂ → FeCl₃
or
2Fe + 3Cl₂ → 2FeCl₃
Problem a:
Mass of reacting iron = 25g
unknown: number of moles of iron
Solution
To find the number of moles, we apply the mole concept using the expression below:
[tex]number of moles = \frac{mass}{molar mass} \\[/tex]
To find the molar mass of the reactant iron, we know atomic mass of iron is 56g.
The molar mass is therefore, 56gmol⁻¹
[tex]number of moles = \frac{25}{56} \\[/tex]
number of moles of the iron reactant = 0.45mole
Problem b:
From the balanced equation of the reaction:
2Fe + 3Cl₂ → 2FeCl₃
2 moles of Fe produces 2 moles of FeCl₃
So 0.45mole of Fe would produce 0.45 mole of FeCl₃
Problem C:
Applying the mole concept;
mass of FeCl₃ = number of moles of FeCl₃ x molar mass of FeCl₃
number of moles of FeCl₃ = 0.45mole
molar mass of FeCl₃ = ?
Atomic mass of Fe = 56g
Cl = 35.5g
Molar mass of FeCl₃ = 56 + (3 x 35.5) = 56 + 106.5 = 162.5gmol⁻¹
mass of FeCl₃ = 0.45 x 162.5 = 73.1g
When 24g of magnesium metal is heated in air, 40g of magnesium oxide is produced. What mass of magnesium would be needed in order to produce 10g of magnesium oxide?
Final answer:
To produce 10g of magnesium oxide, 6g of magnesium would be needed.
Explanation:
To find the mass of magnesium needed to produce 10g of magnesium oxide, we can use the given information about the reaction between magnesium and oxygen. From the given information, we know that when 24g of magnesium is heated in air, 40g of magnesium oxide is produced. This means that the reaction produces a 1:1 ratio between the mass of magnesium and the mass of magnesium oxide. Therefore, if 24g of magnesium produces 40g of magnesium oxide, then 10g of magnesium oxide would require (10g/40g) * 24g = 6g of magnesium.
as electrons pass through a particular device magnets begin to rotate. this rotation is then used to power devices such as ceiling fans this is a description of what happens in a what
Answer:
Motor
Explanation:
This actuation of electric energy to mechanical energy is due to reverse magnetic induction. When you pass a wire coil, with electricity passing through it, along a magnetic field, the coil will rotate according to Fleming’s Left Hand Hand Rule. This principle is harnessed in the making of motors that can be used to power equipments such as fans.
Answer:
D) electric motor
Explanation:
Thats the answer for apex. A) electric generator B) power surge C) battery D) electric motor
A device used to measure small currents is a(n)
Answer:
Ammeter
Explanation:
An ammeter (from Ampere Meter) is a measuring instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters.
When 16.3 g of magnesium and 4.52 g of oxygen gas react, how many grams of magnesium oxide will be formed? Identify the limiting and excess reactants.
Answer:
22.77 g.
he limiting reactant is O₂, and the excess reactant is Mg.
Explanation:
From the balanced reaction:Mg + 1/2O₂ → MgO,
1.0 mole of Mg reacts with 0.5 mole of oxygen to produce 1.0 mole of MgO.
We need to calculate the no. of moles of (16.3 g) of Mg and (4.52 g) of oxygen:no. of moles of Mg = mass/molar mass = (16.3 g)/(24.3 g/mol) = 0.6708 mol.
no. of moles of O₂ = mass/molar mass = (4.52 g)/(16.0 g/mol) = 0.2825 mol.
So. 0.565 mol of Mg reacts completely with (0.2825 mol) of O₂.
∴ The limiting reactant is O₂, and the excess reactant is Mg (0.6708 - 0.565 = 0.1058 mol).
Using cross multiplication:
1.0 mole of Mg produce → 1.0 mol of MgO.
∴ 0.565 mol of Mg produce → 0.565 mol of MgO.
∴ The amount of MgO produced = no. of moles x molar mass = (0.565 mol)(40.3 g/mol) = 22.77 g.
Answer:
[tex]m_{MgO}=11.3gMgO[/tex]
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
[tex]2Mg+O_2\rightarrow 2MgO[/tex]
Hence, for given amounts of magnesium and oxygen, one computes the available moles of magnesium with its given mass and atomic mass and the moles of magnesium that will completely react with 4.52 g of oxygen by using their 2:1 molar ratio in the chemical reaction in order to identify the limiting reactant:
[tex]n_{Mg}^{available}=16.3gMg*\frac{1molMg}{24gMg}=0.679molMg\\\\n_{Mg}^{reacted}=4.52gO_2*\frac{1molO_2}{32gO_2}*\frac{2molMg}{1molO_2} =0.2825molMg[/tex]
In such a way, as just 0.2825 moles of magnesium react, magnesium is identified as the excess reactant and the oxygen the limiting reactant. Furthermore, with the reacting moles, one computes the yielded grams of magnesium oxide as:
[tex]m_{MgO}=0.2825molMg*\frac{2molMgO}{2molMg}*\frac{40gMgO}{1molMgO} \\\\m_{MgO}=11.3gMgO[/tex]
Best regards.
how does nuclear reactor produce electricty
With a process called Fission. This generates heat to produce steam.
During a lunar eclipse, the moon appears to be darkened because _______________ is casting a shadow on it.
the earth
the sun
Mars
Answer:
the earth
Explanation:
because the moon is blocking the light of the sun
If an object moves faster and faster, what must change?
The energy speed!!!!
A balloon was partially filled with helium gas at room temperature. It occupied 4.0 liters of volume at 700.0 mmHg atmospheric pressure. When the balloon was released, it traveled upward until it burst at 99 mmHg atmospheric pressure. (Neglect any force exerted to stretch the rubber balloon.) What was the volume of the balloon when it burst? L
Final answer:
To find the volume of the balloon when it burst at 99 mmHg, we use Boyle's Law. The final volume was calculated to be approximately 28.28 liters.
Explanation:
The volume of the balloon when it burst at 99 mmHg atmospheric pressure can be determined using Boyle's Law, which states that the product of pressure and volume is constant for a given mass of enclosed gas when the temperature is constant (P1V1 = P2V2).
Here, we know the initial pressure (P1) is 700.0 mmHg, the initial volume (V1) is 4.0 liters, and the final pressure (P2) upon bursting is 99 mmHg. To find the final volume (V2), we rearrange the equation to V2 = (P1V1) / P2 and substitute the known values. Doing so gives us V2 = (700.0 mmHg × 4.0 L) / 99 mmHg, which calculates to a volume of approximately 28.28 liters.
what kind of bond is ca-br
Final answer:
The bond between calcium (Ca) and bromine (Br) is an ionic bond, where calcium donates electrons to form Ca2+ ions, and bromine atoms each gain an electron to form Br- ions, creating an ionic compound.
Explanation:
The bond between calcium (Ca) and bromine (Br) in the compound CaBr2 is an ionic bond. This type of bond is formed when one atom (in this case, calcium) donates one or more electrons to another atom (in this case, bromine).
Calcium is a metal with a tendency to lose electrons and form a positive ion (Ca2+), while bromine is a non-metal with a tendency to gain electrons and form a negative ion (Br−).
When calcium gives up two electrons, one for each bromine atom, each bromine atom gains one electron, resulting in two Br− ions. These oppositely charged ions attract each other, creating an ionic bond.
What happens during a endothermic reaction
An endothermic reaction occurs when the energy used to break the bonds in the reactants is greater than the energy given out when bonds are formed in the products. This means that overall the reaction takes in energy, therefore there is a temperature decrease in the surroundings.
Answer:
There is a temperature decrease in the surroundings
Explanation:
An endothermic reaction occurs when the energy used to break the bonds in the reactants is greater than the energy given out when bonds are formed in the products. This means that overall the reaction takes in energy, therefore there is a temperature decrease in the surroundings
What is the mass of 2.45 miles or C3H403?
Answer:
215.6 g.
Explanation:
We have the relation:no. of moles (n) = mass/molar mass.
∴ mass of C₃H₄O₃ = (no. of moles)*(molar mass) = (2.45 mol)(88.0 g/mol) = 215.6 g.
In both liquid water and ice, a hydrogen bond forms between _____.
a) a pair of oxygen atoms on adjacent molecules
b) the oxygen atom of one molecule and a hydrogen atom of an adjacent molecule
c) a pair of hydrogen atoms on adjacent molecules
d) an oxygen atom and a hydrogen atom in the same molecule
Answer:
b) the oxygen atom of one molecule and a hydrogen atom of an adjacent molecule
Explanation:
In a H₂O molecule there are two O-H bonds. The O atom being more electronegative pulls away the shared pair of electron in the covalent bond more towards itself thus O gaining a partial negative charge and H atom getting a partial positive charge. Thus a dipole exists in the O-H bond in the H₂O molecules. Thus in both liquid water and solid ice there is a weak attraction or hydrogen bond between the oxygen atom of one H₂O molecule and a hydrogen atom of an adjacent H₂O molecule.
The variable that a scientist observes to change while conducting an experiment is called the ___ variable.
A.) mainipulated
B.) responding
C.) independent
Great Question!
The Answer Would Be "B" The "RESPONDING" Variable
The variable that a scientist observes to change while conducting an experiment is called the responding variable.
how many grams of silver chromate, Ag2CrO4, are produced from 57.7
g of silver nitrate, AgNO3?
Choose the number of significant figures indicated 0.06
Answer:
2
Explanation:
what is lithosphere
Answer:
the rigid outer part of the earth, made up of the crust and upper mantle.
Explanation:
Google’s definition
A lithosphere is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.
the equivalent weight of sodium thiosulfate
The equivalent weight is the gram molecular weight divided by the number of electrons lost or gained by each molecule; For sodium thiosulfate (Na2S2O3·5H2O), this is (248.17/1) g.
How many kJ of energy will be released when 4.72g of carbon react with excess oxygen to produce carbon dioxide (delta H is -393.5 kJ)
Answer:
155 kJ of energy will be released.
Explanation:
The [tex]\rm \Delta H\textdegree[/tex] ([tex]\rm \Delta H \textdegree_\text{rxn}[/tex] in some textbooks) here stands for standard enthalpy change per mole reaction. To find the amount of energy released in this reaction, start by finding the number of moles of this reaction that will take place.
How many moles of atoms in 4.72 grams of carbon?
Relative atomic mass data from a modern periodic table:
C: 12.01.[tex]\displaystyle n = \frac{m}{M} = \rm \frac{4.72\;g}{12.01\; g\cdot mol^{-1}} = 0.393006\; mol[/tex].
The coefficient of carbon in the equation is one. In other words, each mole of the reaction will consume one mole of carbon. Oxygen is in excess. As a result, [tex]\rm 0.393006\; mol[/tex] of carbon will support [tex]\rm 0.393006\; mol[/tex] of the reaction.
How much energy will be released?
The [tex]\rm \Delta H\textdegree{}[/tex] value here is negative. But don't panic. [tex]\rm \Delta H\textdegree{}[/tex] is the same as the chemical potential energy of the reactants minus the products in one mole of the reaction. [tex]\rm \Delta H\textdegree{} = -393.5\;kJ[/tex] means that the chemical potential energy drops by [tex]\rm 393.5\; kJ[/tex] during each mole of the reaction (with the coefficients as-is.) Those energy difference will be released as heat. In other words, one mole of the reaction will release [tex]\rm 393.5\;kJ[/tex] of energy.
The 4.72 grams of carbon will support [tex]\rm 0.393006\; mol[/tex] of this reaction. How much heat will that [tex]\rm 0.393006\; mol[/tex] of reaction release?
[tex]Q = n \cdot (-\Delta \text{H}\textdegree{}) = \rm 0.393006\times 393.5 = 155\;kJ[/tex].
As a side note, the mass of carbon 4.72 grams is the least significant data in this question. There are three significant figures in this value. As a result, keep more than three significant figures in calculations but round the final result to three significant figures.
The energy released when 4.72g of carbon reacts with excess oxygen to form CO₂ is -154.8 kJ.
To determine how many kJ of energy are released when 4.72g of carbon reacts with excess oxygen to produce carbon dioxide, we use the given enthalpy change (ΔH) for the reaction:
First, we need to find the number of moles of carbon in 4.72g:
Molar mass of carbon = 12 g/mol
Moles of carbon = mass / molar mass = 4.72 g / 12 g/mol = 0.3933 mol
The reaction for the combustion of carbon to form CO₂ is exothermic, with ΔH = -393.5 kJ/mol.
The total energy released is calculated as follows:
Energy released = moles of carbon x ΔH
Energy released = 0.3933 mol x -393.5 kJ/mol = -154.8 kJ
Thus, the energy released when 4.72g of carbon reacts with excess oxygen is -154.8 kJ.
What does Hund's rule state?
Answer:
Explanation:
Hund's Rule of Maximum Multiplicity states that electrons go into degenerate orbitals of sub-orbitals(p, d and f) singly before pairing commences.
Hund's rule is useful in determining the number of unpaired electrons in an atom. Hence, it explains some of the magnetic properties of elements.
An element whose atoms or molecules contain unpaired electrons is paramagnetic.
The element whose atoms or molecules contain orbitals that are all filed up with paired electron is diamagnetic.
Hund's rule states that in degenerate orbitals, electrons must occupy orbitals singly and with parallel spins before pairing up. This ensures the lowest-energy electron configuration. A common example is seen in the p orbitals for nitrogen.
Hund's Rule
Hund's rule states that the lowest-energy electron configuration for an atom is the one that has the maximum number of electrons with parallel spins in degenerate orbitals. This means that in any given sub-level other than the s orbital, electrons will occupy each orbital singly before starting to pair up. For instance, in the p sublevel, which has three degenerate orbitals, each of these orbitals will get one electron before any one of them gets a second electron with the opposite spin.
An easy way to visualize this is by considering the p orbitals (px, py, and pz) for an atom like nitrogen, which has three electrons in its p sublevel. According to Hund's rule, each of these three electrons will occupy one of the p orbitals singly, with parallel spins, resulting in a more stable and lower-energy configuration.
What kind of system is the carbon cycle
Answer:
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.
The carbon cycle is a biological and geological system composed of two interconnected sub-cycles - the biological carbon cycle and the biogeochemical carbon cycle. The biological carbon cycle involves the exchange of carbon among living organisms through processes like photosynthesis and respiration, while the biogeochemical carbon cycle involves the long-term cycling of carbon through the Earth's atmosphere, water bodies, and interior. Human activities like burning of fossil fuels can accelerate these cycles and contribute to global climate change.
Explanation:The carbon cycle is a type of system in biology that can be broadly divided into two interconnected sub-cycles. One sub-cycle deals with the rapid exchange of carbon among living organisms, and the other deals with the long-term cycling of carbon through geologic processes. These processes together help in the transfer and recycling of carbon in different forms throughout the ecosystem.
In the Biological Carbon Cycle, living organisms play a crucial role. Autotrophs, like plants, absorb carbon dioxide from the atmosphere and convert it into glucose through photosynthesis. This glucose is used by heterotrophs, like animals, for their energy needs. In this process, carbon gets incorporated in their bodies. When these animals die, the carbon gets returned to the atmosphere through decomposition. Moreover, marine autotrophs obtain carbon dioxide in the dissolved form (carbonic acid, H₂CO3). Through this biological carbon cycle process, photosynthetic organisms are responsible for maintaining approximately 21 percent of the Earth's oxygen content.
In the Biogeochemical Carbon Cycle, carbon is stored in what are known as carbon reservoirs that include the atmosphere, bodies of liquid water (mostly oceans), ocean sediment, soil, land sediments (including fossil fuels), and the Earth's interior. Over longer periods, microorganisms capable of digesting non-bioavailable carbon like coal can release it as gas, making it available for other living organisms. This process accelerates when humans burn fossil fuels, releasing large amounts of carbon dioxide into the atmosphere. Most scientists agree that the high atmospheric carbon dioxide is a major cause of global climate change.
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A fact is something that has been proven to be true.
True
False
i am in a test :/
Answer:
True.
Explanation:
the answer to your question is True !
Metalic element in list.
Metallic element in list of paper is Titan.
Balance the following equation. Choose "blank" if no coefficient other than 1 is needed.
Choose Pb + Choose AgNO 3 Choose Pb(NO 3 ) 2 + Choose Ag
Answer:
Pb + 2AgNO3 ---> Pb(NO3)2 + 2Ag
Explanation:
The lead Pb2+ ion has a valency of 2 and therefore combines with 2 nitrate ions (NO3)-..
[tex]Pb + 2AgNO_3[/tex] → [tex]Pb(NO_3)_2 + 2Ag[/tex]
What is a balanced chemical equation?An equation that has an equal number of atoms of each element on both sides of the equation is called a balanced chemical equation.
[tex]Pb + 2AgNO_3[/tex] → [tex]Pb(NO_3)_2 + 2Ag[/tex]
This is the balanced chemical equation. Where there are 1 Pb, 2 Ag, 2N, and 6 oxygen atoms on both sides.
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An electron moved from a higher energy level to a lower energy level. What most likely happened during the transition?
Answer: A. A photon was released.
An electron moved from a higher energy level to a lower energy level. What most likely happened during the transition? (5 points)
A. A photon was released.
B. A photon was absorbed.
C. A fixed amount of energy was absorbed.
D. A random amount of energy was released.
Explanation:
I just took the test and A. A photon was released is the correct answer!
Good Luck!!
( P.S.- I just used the other answer on the test and it was incorrect, but this one is correct because I finished the test and got the answer key!)
During the electron's transition from a higher to a lower energy level, it most likely released energy, possibly in the form of light, consistent with Bohr's model of the atom.
Explanation:When an electron moves from a higher energy level to a lower energy level, it most likely emitted energy. This concept is grounded in Bohr's model of the atom where each electron orbit is an energy level with a specific energy value. A transition between these levels involves a change in the electron's energy, corresponding to the energy difference between the levels.
For example, if an electron moves from level 8 to level 1, it descends through several energy levels and, according to Bohr's model, emits energy at each transition. This energy can be quantified, such as in the change of -10.2 eV from a higher to a lower state, releasing 10.2 eV of energy. The emitted energy often manifests as light, with the color depending on the energy change involved.
What is the percent composition of silicon in silicon carbide (SiC)? A. 28% B. 50% C. 70% D. 142%
Hey there!
Here goes your answer ↓
Question :- What is the percent composition of silicon in silicon carbide (SiC)?
A. 28%
B. 50%
C. 70%
D. 142%
Answer :- The percentage of silicon content in silicon carbide (SiC) is option (C) 70%.
Hope it helps you.
Have a great day ahead!
Answer : The correct option is, (C) 70%
Explanation : Given,
Molar mass of Si = 28.09 g/mole
Molar mass of C = 12 g/mole
Molecular mass of SiC = 28.09 + 12 = 40.09 g/mole
To calculate the mass percent of an element in a compound, we use the equation:
[tex]\text{Percent composition of Si}=\frac{\text{Mass of Si in compound}}{\text{Mass of the compound}}\times 100[/tex]
Now put all the given values in above equation, we get:
[tex]\text{Percent composition of Si}=\frac{28.09g}{40.09g}\times 100=70\%[/tex]
Hence, the percentage composition of Si in the given compound is 70%
What was Pangaea?when did it form and when did it break apart it was
Pangaea was a supercontinent. It is the last supercontinent that had all of the continental masses joined as one, though after its breaking apart there were two other supercontinents which were very short lasting. This supercontinent formed from the pre-existing continental masses that moved toward one another and merged by the late Paleozoic era, approximately around 335 million years ago. Pangaea existed until the early Mesozoic era, and it started to break apart around 175 million years ago. From the breaking apart of this supercontinent, initially formed Laurasia and Gondwanaland, and from the further breaking apart of these two we got the modern day continents.