Answer:
The specific heat of the unknown substance is 1.22 J/g.°C.
Explanation:
Knowing that:Heat lost by substance (Qc) = Heat gained by the water (Qw) ,
- (Qc) = (Qw).
We can calculate the amount of heat (Qw) gained by water using the relation:
Qw = m.c.ΔT,
where, Qw is the amount of heat released to water (Q = ??? J).
m is the mass of water (m = 110.0 g).
c is the specific heat capacity of solution (c = 4.18 J/g.°C).
ΔT is the difference in T (ΔT = final temperature - initial temperature = 32.4°C - 24.2°C = 8.2°C).
∴ Q = m.c.ΔT = (110.0 g)(4.18 J/g.°C)(8.2°C) = 3770.36 J.
Now, the amount of heat lost by the substance (Qc) = - 3770.36 J.(Qc) = m.c.ΔT,
where, Qc is the amount of heat lost by substance (Qc = - 3770.36 J).
m is the mass of water (m = 42.5 g).
c is the specific heat capacity of solution (c = ??? J/g.°C).
ΔT is the difference in T (ΔT = final temperature - initial temperature = 32.4°C - 105.0°C = -72.6°C).
∴ (- 3770.36 J) = (42.5 g)(c)(-72.6°C).
∴ c = (- 3770.36 J)/(42.5 g)(-72.6°C) = 1.222 J/g.°C.
Which pair of elements can be used to determine the age of a fossil that is over one billion years old?
lead, which is radioactive, and uranium, which is stable
carbon, which is radioactive, and nitrogen, which is stable
argon, which is radioactive, and lead, which is stable
potassium, which is radioactive, and argon, which is stable
Answer: Option (4)
Explanation: The most efficient radioactive method used for the determination of fossil age which is about one billion years old is the Potassium-Argon method (⁴⁰K-⁴⁰Ar).
Potassium-Argon method is generally used to date fossils which are more than 1.2 billion years old as its half life is almost about 1.2 billion years. Potassium is highly radioactive, which converts into Argon and becomes stable.
Uranium and Carbon are also highly radioactive whereas Lead and Nitrogen are stable elements.
¹⁴C-¹⁴N is not an efficient method as it has a half life of only about 5700 years.
Thus the correct answer is option (4).
Answer:
The answer is D) potassium, which is radioactive, and argon, which is stable
Explanation:
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What is the correct way to represent 5600 L using scientific notation?
Answer:
5.6 * 10^3
this is because when thinking about scientific notation you know that you have to include a decimial and how many times you are moving it and whether it is a negative of a positive.
this means that you would take 5600 and you would put the decimal inbetween 5 and 6 because they are significant numbers and then you would have to figure out how many places to the right you need to go inorder to make it 5600
meaning you have to move it three times therefore it becomes
5.6 * 10^3
[tex]5.6*10^{3}[/tex] is the correct way to represent 5600 L using scientific notation.
What is scientific notation?In case your decimal quantity is extra than 10, rely on the number of instances of the decimal movements to the left, and upload this variety to the exponent. division: To divide numbers in medical notation, first divide the decimal numbers. Then subtract the exponents of your strength of 10.
How do you change from standard form to clinical notation?To alternate more than a few from scientific notation to traditional form, circulate the decimal point to the left (if the exponent of ten is a poor variety), or to the right (if the exponent is fine). You must pass the point as often as the exponent indicates. Do no longer write the strength of ten anymore.
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What is the indicator of the number of ions in solution?
the amount of conductivity
the amount of precipitate
the amount of solute added
The amount of conductivity is the indicator of the number of ions in a solution, with higher ion concentrations leading to greater conductivity. This is crucial for predicting precipitation when solutions are mixed.
Explanation:The indicator of the number of ions in solution is the amount of conductivity. This is because the concentration of ions in solution directly affects its conductivity. Strong electrolytes such as potassium nitrate (KNO3) will dissolve to form a high concentration of ions, leading to higher conductivity compared to weak electrolytes like acetic acid (CH3COOH), and especially non-electrolytes that do not form ions in solution. It is also worth noting that the temperature can affect conductivity, as higher temperatures increase the solubility of substances, potentially resulting in higher ion concentrations.
Understanding ion concentration is also essential in predicting whether a precipitate will form when two solutions are mixed. By calculating the ion product and comparing it to the solubility product constant (Ksp), chemists can determine the state of a solution (unsaturated, saturated, or supersaturated) and if a mixing of solutions will result in precipitation.
How many grams of oxygen gas are contained in a 15 L sample at 1.02 atm and 28°C? Please show your work.
Answer:
0.019 g.
Explanation:
Firstly, we need to find the no. of moles of oxygen gas:We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm (P = 1.02 atm).
V is the volume of the gas in L (V = 15.0 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 28°C + 273 = 301.0 K).
∴ n = PV/RT = (1.02 atm)(15.0 L)/(0.0821 L.atm/mol.K)(301.0 K) = 0.62 mol.
To find the mass of oxygen gas, we have:no. of moles = mass/molar mass.
∴ mass of oxygen = (no. of moles)(molar mass) = (0.62 mol)(32.0 g/mol) = 0.019 g.
Which class of molecules functions as chemical signals? hormones water carbohydrates proteins
Answer:
hormones - the first choice
Answer:
hormones
Explanation:
Hormones are chemical signals secreted by the endocrine glands. Each cell has receptors for the hormone molecule. Hormone secreted in the blood binds to its specific receptor on the cell surface. After binding to its receptors hormones transfer signal to the interior of the cell. Hormones are responsible for the transduction of cell signal. A very common example of hormone is insulin.
If 10.0 mL of 0.350 M aqueous NaNO3 is mixed with 50.0 mL of 0.170 M aqueous KNO3, what is the molarity of nitrate ion?
A) 0.185 M
B) 0.200 M
C) 0.260 M
D) 0.520 M
Answer:
0.200 mol/L
Explanation:
1. Moles of nitrate in first solution
Moles = volume × concentration
n = 0.0100 L × 0.350 mol/L =0.003 500 mol
2. Moles of nitrate in second solution
n = 0.0500 L × 0.170 mol/L = 0.008 500 mol
3. Total moles of nitrate
n = 0.003 500 + 0.008 500 = 0.012 000 mol
4. Total volume of solution
V = 10.0 + 50.0 = 60.0 mL = 0.0600 L
5. New concentration of nitrate
c = moles/litres
c = 0.012 000 mol/0.0600 L = 0.200 mol/L
The molar concentration of nitrate ion is 0.200 mol/L.
In the following table, all the columns for the element calcium are filled out correctly. Element Electron Structure of Atom Electron Structure of Ion Net Ionic Charge Calcium 1s22s22p63s23p64s2 1s32s22p63s23p64s1 +1 True False
Answer:
False
Explanation:
Calcium is an element that belongs to the second group on the periodic table. Calcium has a valency of two and would readily loose both electrons in order to achieve stability when forming bonds.
It has 20 electrons.
Calcium would favor ionic bonds when combining with other atoms and by the virtue of this, it would readily transfer its two outermost electrons. This would make its atom mimic that of Argon-18.
The correct information is given below:
Element: Calcium(Ca)
Electron structure of atom: 1S²2S²2P⁶3S²3P⁶4S²
Electron structure of ion: 1S²2S²2P⁶3S²3P⁶
Net ionic charge: +2
The assertion in the table is incorrect. A calcium ion has an electron configuration of 1s22s22p63s23p6 and a net ionic charge of +2, not +1.
Explanation:The provided electron configuration of the calcium ion is not accurate. The given configuration for the element of calcium (1s22s22p63s23p64s2) represents a neutral calcium atom, not a charged ion. When calcium becomes an ion, it loses two electrons to achieve a stable electron configuration (1s2 2s2 2p6 3s2 3p6), resulting in a net ionic charge of +2 for calcium, not +1. The electron configuration of Calcium ion should therefore be 1s22s22p63s23p6.
So, the assertion that all columns for calcium are filled out correctly in the table is ultimately false. Calcium loses two electrons when it becomes an ion, and therefore has a net ionic charge of +2, not +1.
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Which of the following best describes a chain reaction? Select one: a. Neutrons from splitting atoms continue to split other atoms, releasing more neutrons. b. Chemicals released from splitting atoms cause other atoms to split. c. Splitting atoms bump into neighboring atoms, causing them to split. d. A splitting atom causes the atom directly beside it to also split.
Chain reaction is best described as neutrons from splitting atoms continue to split other atoms, releasing more neutrons.
What is Neutron?This is referred to as a subatomic particle which has a neutral charge and is produced in preceding fusion of the chain reaction.
The neutron produced initiates the splitting of the atoms which was why option A was chosen in this regard.
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A chain reaction, in the context of nuclear physics, is when neutrons released from a fission event cause other atoms to undergo fission. An example is the fission process of uranium-235, which releases additional neutrons that can trigger further fission, thus leading to an exponentially increasing reaction.
Explanation:The best description for a chain reaction among the options presented is: 'Neutrons from splitting atoms continue to split other atoms, releasing more neutrons' (Option A). This process refers to a series of nuclear fissions (splitting of a nucleus), where the released neutrons from one fission event cause further fissions. As an example, when undergoing fission, uranium-235 (U-235) produces two medium-sized nuclei and releases two or three neutrons. These neutrons can then cause the fission of other U-235 atoms, which in turn provide more neutrons that can cause more fissions, leading to a nuclear chain reaction.
However, it should be noted that a chain reaction depends on several factors, including how many neutrons are produced in an average fission and how easy it is to induce a particular type of nuclear fission.
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What separation technique would most likely be used if a solvent were saved?
Answer:
Distillation
Explanation:
If the solute is a solid or a liquid with a boiling point at least 30 °C different from that of the solvent, you can use the technique of distillation.
The solvent will boil before the solid or a higher-boiling liquid.
A liquid solute with a lower boiling point than the solvent will boil off first, and then you can distill off the solvent.
Answer:
Distillation
Explanation:
Distillation is a process known long ago and according to some authors was created by the Alchemists at a time where Chemistry was not yet recognized as Science and was closely linked to religious precepts.
Basically the distillation process is a process of physical separation and is used to separate homogeneous mixtures from heating. To separate a solid-liquid type mixture we use simple distillation and to separate liquid-liquid mixtures we use fractional distillation.
If the mass of the products measured 120g what would the mass of the reactants
A. 30g
B. 60g
C. 120g
D. 240g
a propane torch is lit inside a hot air balloon during preflight preparations to inflate the balloon. which condition of the gas remains constant
Answer:
The pressure remains constant
Explanation:
this is an example in charles law where as the temperature increases so does the volume.
Answer:
The correct answer is "Pressure".
Explanation:
As the propane torch is ignited inside the hot air balloon, the volume of the gas increases and the temperature of the gas also increases. This causes the density of the gas to decrease, keeping the pressure constant throughout the balloon, regardless of the small amount of gas lost through the balloon hole.
Have a nice day!
which of these best explains the ability of small insects to walk on the surface of still water?
a.) water molecules at the surface experience fewer hydrogen bonds than water molecules within the liquid
b.) the insects’ feet are coated with ionic compounds
c.) water has a very high specific heat
d.) water molecules near the surface produce more buoyant force than water molecules within the liquid
THE ANSWER WAS NOT D.
Answer:
A.
Explanation:
Smaller insects can walk on water due to surface tension. The force that a smaller insect makes on the water is less than the water and as such the bug will "float."
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A sample of gas is in a rigid cylinder with a movable piston. The pressure of the gas is kept constant. If the Kelvin temperature of the gas is
doubled, the volume of the gas is
O 1.
2
halved
doubled
tripled
unchanged
Submit Retry Answer
Previous
Answer:
The volume will double, if the temperature of the gas is doubled as temperature and volume are directly proportional.
Answer:
If the Kelvin temperature of the gas is doubled, the volume of the gas is doubled.
Explanation:
To calculate the final volume of the system, we use the equation given by Charles' Law.
This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex] (at constnat pressure)
where,
[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.
[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.
We are given:
[tex]T_2=2T_1[/tex]
[tex]V_2=?[/tex]
[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]
[tex]\frac{V_1}{T_1}=\frac{V_2}{2T_1}[/tex]
[tex]V_2=2V_1[/tex]
If the Kelvin temperature of the gas is doubled, the volume of the gas is doubled.
Which of the following best describes sleet?
A- A liquid form of precipitation that forms in temperatures above 0° C
B- A form of solid precipitation that forms when raindrops freeze
C- Chunks or balls of ice will that will continue to grow larger and become heavier
D- Precipitation that forms in clouds when water vapor freezes into ice crystals
Answer:
B- A form of solid precipitation that forms when raindrops freeze
Explanation:
A form of solid precipitation that forms when raindrops freeze best describes sleet.
The study of chemicals and bonds is called chemistry. There are two types of elements and these are metals and nonmetals.
The correct answer is option B which is A form of solid precipitation that forms when raindrops freeze
What is the freezing point?The temperature point at which the liquid starts changing itself to solid is called the freezing point.What is sleet?Rain and snow mixed is precipitation composed of rain and partially melted snow. Unlike ice pellets, which are hard, and freezing rain, which is fluid until striking an object, this precipitation is soft and translucent, but it contains some traces of ice crystals from partially fused snowflakes.Hence, A form of solid precipitation that forms when raindrops freeze best describes sleet.
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A. Explain, in terms of particles, why NaCl(s) does not conduct electricity.
Answer:
Ionic bonds hold charged particles in solid NaCl together, such that they are unable to move or conduct electricity.
Explanation:
Consider an electric current that flows through a conductor: charge moves in a uniform direction from one end of the conductor towards the other.
Thus, there are two conditions for a substance to conduct electricity:
The substance shall contain charged particles, andThese charged particles shall be free to move across the substance.A conductor of electricity shall meet both requirements.
Now, consider the structure of solid NaCl [tex]\rm NaCl\;(s)[/tex]. NaCl is an ionic compound. It contains an ocean of oppositely charged ions:
Positive [tex]\rm Na^{+}[/tex] ions, andNegative [tex]\rm Cl^{-}[/tex] ions.Ions carry charge. Thus, solid NaCl contains charged particles and satisfies the first condition.
Inside solid NaCl [tex]\rm NaCl\;(s)[/tex], electrostatic attractions ("ionic bonds") between the oppositely charged ions hold these ions in rigid ionic lattices. These ions are unable to move relative to each other. As a result, they cannot flow through the solid to conduct electricity. Under solid state, NaCl is unable to satisfy the second condition.
As a side note, melting NaCl into a liquid breaks the ionic bonds and free the ions from the lattice. Liquid NaCl is a conductor of electricity.
NaCl(s) does not conduct electricity because, in its solid state, the sodium and chloride ions are held in a fixed lattice structure and cannot move freely.
Electrical conductivity in a substance is dependent on the presence of charged particles that can move freely. In the case of sodium chloride (NaCl), which is an ionic compound, the structure is composed of sodium cations (Na^+) and chloride anions (Cl^-) arranged in a crystalline lattice. When NaCl is in the solid state, the ions are locked into place by strong electrostatic forces of attraction between the oppositely charged ions. These forces hold the ions in a rigid, three-dimensional array, preventing them from moving about freely.
For a material to conduct electricity, it must have mobile charge carriers. In metals, these charge carriers are delocalized electrons that can move throughout the metal. In ionic solutions or molten ionic compounds, the ions themselves are the charge carriers, and they can move when an electric field is applied. However, in solid NaCl, the ions are immobile due to the lattice structure, and thus, there are no free charge carriers to transport electric charge. As a result, solid NaCl does not conduct electricity.
When NaCl is dissolved in water or melted into a liquid, the ions are no longer fixed in place and can move freely. In this state, NaCl does conduct electricity because the ions can act as charge carriers, moving towards the electrodes of opposite charge under an applied electric field
What is the formula unit for a compound made from Pb4+ and oxygen?
Answer : The formula unit of compound will be, [tex]PbO_2[/tex]
Explanation :
As we know that one atom of oxygen contains (2-) charge and one atom of lead contains (4+) charge. So, to balance the of charges of lead, the 2 oxygen atoms combine with the 1 lead atom. Thus, the compound formed will be, [tex]PbO_2[/tex].
That means, when [tex]Pb^{4+}[/tex] combine with oxygen that is, [tex]O^{2-}[/tex], it gives [tex]PbO_2[/tex] by the criss-cross method.
Criss cross method : It is a method of determining the chemical formula.
The formula unit is a shown below.
Answer:
Pb02
Explanation:
guy above was correct i just took my test
A sample of hydrated tin (II) chloride (SnCl2) has a mass of 4.90 g. When it is dehydrated, it has a mass of 4.10 g. Which is the correct chemical formula for the hydrate?
SnCl2•2H2O
SnCl2•4H2O
SnCl2•6H2O
Answer:
SnCl₂·2 H₂O.
Explanation:
Relative atomic mass data from a modern periodic table:
Sn: 118.710;Cl: 35.45;H: 1.008;O: 15.999.How many moles of SnCl₂ formula units in this sample?
The first mass 4.90 grams contain both the SnCl₂ formula units and a number of water molecules. Luckily, the mass of the dehydrated salt 4.10 grams contains only SnCl₂.
Formula mass of tin (II) chloride SnCl₂:
[tex]M(\rm SnCl_2) = 118.710 + 2\times 35.45 = 189.610\; g\cdot mol^{-1}[/tex].
Number of moles of tin (II) chloride SnCl₂ formula units in this sample:
[tex]\displaystyle n(\mathrm{SnCl_2}) = \frac{m}{M} = \rm \frac{4.10\; g}{189.610\; g\cdot mol^{-1}} = 0.0216233\; mol[/tex].
How many moles of water molecules H₂O in this sample?
Water of crystallization exist as H₂O molecules in typical hydrated salts. The molar mass of these molecules will be:
[tex]M(\rm H_2O) = 2\times 1.008 + 15.999 = 18.015\; g\cdot mol^{-1}[/tex].
The mass of water in the hydrated salt is the same as the mass that is lost when the water molecules are removed and the salt is dehydrated.
In other words,
[tex]\begin{aligned}m(\text{Water of Hydration})&=m(\text{Hydrated Sample}) - m(\text{Anhydrous Sample}) \\ & = \rm 4.90\; g - 4.10\; g \\ &= \rm 0.80\; g\end{aligned}[/tex].
[tex]\displaystyle n(\mathrm{H_2O}) = \frac{m}{M} = \rm \frac{0.80\; g}{18.015\; g\cdot mol^{-1}} = 0.0444074\; mol[/tex].
What's the coefficient in front of water in the formula of this hydrated salt? In other words, how many water molecules are there in the compound for each SnCl₂ formula unit?
[tex]\displaystyle \frac{n(\mathrm{H_2O})}{n(\mathrm{SnCl_2})} = 2.05 \approx 2[/tex].
There are approximately two water molecules for each SnCl₂ formula unit. The formula of this compound shall thus be [tex]\rm SnCl_2 \cdot 2H_2 O[/tex].
The correct chemical formula for the hydrated tin (II) chloride, given the mass change upon dehydration, is SnCl₂·2H₂O, reflecting that two water molecules are associated with each formula unit of the compound. Option A is correct.
To find the correct chemical formula for the hydrated tin (II) chloride (SnCl2), we begin by calculating the mass of water in the hydrate, which is obtained by subtracting the mass of the dehydrated compound (4.10 g) from the mass of the hydrated compound (4.90 g).
This gives us a mass of 0.80 g for the water. Next, we must calculate the moles of SnCl₂ and H₂O present. The molar mass of SnCl₂ is approximately 189.60 g/mol and that of H₂O is about 18.015 g/mol. The mass of SnCl₂ in the sample is 4.10 g, which equates to about 0.0216 moles of SnCl₂.
The mass of water is 0.80 g, which gives us approximately 0.0444 moles of water. The mole ratio of water to SnCl₂ is therefore 0.0444/0.0216, which simplifies to approximately 2. Therefore, the chemical formula that matches this hydration level is SnCl₂·2H₂O, indicating that each formula unit of tin (II) chloride is associated with two water molecules.
Hence, A. is the correct option.
The complete question is:
A sample of hydrated tin (II) chloride (SnCl₂) has a mass of 4.90 g. When it is dehydrated, it has a mass of 4.10 g. Which is the correct chemical formula for the hydrate?
A. SnCl₂•2H₂O
B. SnCl₂•4H₂O
C. SnCl₂•6H₂O
According to Le Chatelier’s principle, what happens when the concentration of reactants is doubled in a chemical reaction that was in equilibrium?
The equilibrium shifts to the right to favor the formation of products.
The equilibrium shifts to the left to favor the formation of reactants.
The equilibrium is unaffected by the increase in concentration.
The equilibrium is lost because the concentrations have been disturbed.
Answer:
will shift to right
Explanation:
this will result in the formation of more product
According to Le Chatelier’s principle, when the concentration of reactants is doubled the equilibrium shifts to the right to favour the formation of products and the correct option is option 1.
What is Chemical Equilibrium?Chemical equilibrium refers to the state of a system in which the concentration of the reactant and the concentration of the products do not change with time, and the system does not display any further change in properties.
It is the state of a reversible reaction where the rate of the forward reaction equals the rate of the reverse reaction. While a reaction is in equilibrium the concentration of the reactants and products are constant.
Therefore, According to Le Chatelier’s principle, when the concentration of reactants is doubled the equilibrium shifts to the right to favour the formation of products and the correct option is option 1.
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How much energy is generated from freezing 2.5 g water?
Answer:
Probably, 200 calories.
Explanation:
Answer:
2.5 g x 1 mol/18.02 g x 6.03 kJ/mol
Explanation:
use enthalpy of fusion for both thawing or freezing. The only difference for thawing or freezing would be that when freezing, energy is released (generated) and heat is on the product side, but when thawing , energy is consumed and it is on the reactant side. So for thawing or freezing use 6.03 kJ/mol.
How would one convert 125lb to kilograms
Answer:
56.699 kilograms
Explanation:
1 pound (lb) is equal to 0.45359237 kilograms (kg).
The mass m in kilograms (kg) is equal to the mass m in pounds (lb) times 0.45359237
A 20 liter cylinder of helium at a pressure of 150 atm and a temperature of 27°C is used to fill a balloon at 1.00 atm and 37°C. What is the volume of the balloon?
A.
0.14 liters
B.
3000 liters
C.
2900 liters
D.
2400 liters
E.
3100 liters
Answer:The number of moles will remain the same in the two cases
so we can equate using ideal gas equation which is PV =nRT
V2 = 3100 L
Explanation:
Answer: E. 3100 liters
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 150 atm
[tex]P_2[/tex] = final pressure of gas = 1 atm
[tex]V_1[/tex] = initial volume of gas = 20 L
[tex]V_2[/tex] = final volume of gas = ?
[tex]T_1[/tex] = initial temperature of gas = [tex]27^oC=273+27=300K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]37^oC=273+37=310K[/tex]
Now put all the given values in the above equation, we get the final pressure of gas.
[tex]\frac{150atm\times 20L}{300K}=\frac{1atm\times V_2}{310K}[/tex]
[tex]V_2=3100L[/tex]
Therefore, the volume of the baloon is 3100 L.
In an AP, sum of four consecutive terms is 28 and their sum of their squares is 276. Find the four numbers.
10pt if given the correct answer I will mark you as brainliest
An ordered list of chemical substances is shown.
Chemical Substances
1 Al
2 O2
3 H2O
4 SO2
5 Al2O3
Which substances in the list can be used to write a complete combustion reaction?
A- 1, 2, and 3
B- 1, 4, and 5
C-1, 2, and 5
Answer:
C
Explanation:
4(Al)+3(O2)==2(Al2O3)
Also, i'm in sixth grade just took a leson on a text book so may be wrong but i'm prety sure it's the correct nswer because x(Al)+y(O2) can not make hydregen for the h2o and for b, al+so2 = al2O3 makes sense but where did the sulfer go?
Answer:
C- 1, 2 and 5
Explanation:
There are many reactions that occur in the world, and one of the more important ones are known as combustion reactions. These reactions always involve the reaction between oxygen and another element/molecule/compound. So automatically, option 2 needs to be correct, so any answer that does not have option 2 in it (B) is incorrect.
Another important factor of combustion reactions is that they give off heat, because they are exothermic reactions, however since there is no indication of energy levels, so the answer in this question cannot be determined through that method.
One important law in all reactions is the conservation of matter, so whatever atoms enter the chemical reaction, have to exit the chemical reaction (no atoms can suddenly appear without having been there originally. For example, if only oxygen and hydrogen enter a reaction, only a product with oxygen and hydrogen can exit the reaction, it is impossible to have a product containing chlorine, if no chlorine was part of the reactants). By this logic, it is impossible to have water (H₂O) as a product, if the reactants are 1 and 2 (Al and O₂), hence option A is incorrect.
The only other option left is option C, and this option is correct because the overall balanced reaction would look like such:
4Al + 3O₂ --> 2Al₂O₃
This reaction obeys the law of conservation of matter, hence, Option C is correct.
55 L of a gas at 25oC has its temperature increased to 35oC. What is its new volume?
Answer:
Approximately 56.8 liters.
Assumption: this gas is an ideal gas, and this change in temperature is an isobaric process.
Explanation:
Assume that the gas here acts like an ideal gas. Assume that this process is isobaric (in other words, pressure on the gas stays the same.) By Charles's Law, the volume of an ideal gas is proportional to its absolute temperature when its pressure is constant. In other words
[tex]\displaystyle V_2 = V_1\cdot \frac{T_2}{T_1}[/tex],
where
[tex]V_2[/tex] is the final volume, [tex]V_1[/tex] is the initial volume, [tex]T_2[/tex] is the final temperature in degrees Kelvins.[tex]T_1[/tex] is the initial temperature in degrees Kelvins.Convert the temperatures to degrees Kelvins:
[tex]T_1 = \rm 25^{\circ}C = (25 + 273.15)\; K = 298.15\; K[/tex].
[tex]T_2 = \rm 35^{\circ}C = (35 + 273.15)\; K = 308.15\; K[/tex].
Apply Charles's Law to find the new volume of this gas:
[tex]\displaystyle V_2 = V_1\cdot \frac{T_2}{T_1} = \rm 55\;L \times \frac{308.15\; K}{298.15\; K} = 56.8\; L[/tex].
What is the percentage by mass of silicon (si) in iron aluminum silicate (Fe3Al2(SiO4)3)?
Answer:
16.93%.
Explanation:
If we have 1.0 mol of Fe₃Al₂(SiO₄)₃:∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = (no. of moles of Fe₃Al₂(SiO₄)₃)(the molecular mass of Fe₃Al₂(SiO₄)₃)
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = (1)(the molecular mass of Fe₃Al₂(SiO₄)₃) = (the molecular mass of Fe₃Al₂(SiO₄)₃).
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = 3(atomic weight of Fe) + 2(atomic weight of Al) + 3(molecular weight of (SiO₄)₃) = 497.7474 g.
The mass of Si in 1.0 mole of Fe₃Al₂(SiO₄)₃ = 3(atomic mass of Si) = 3(28.0855 g/mol) = 84.2565 g.
∵ The mass % of Si = (the mass of Si)/(the mass of Fe₃Al₂(SiO₄)₃) = (84.2565 g)/(497.7474 g) = 16.93%.
Answer:
16.7%
Explanation:
A 250 g sample of water with an initial temperature
of 98.8 Closes 6500 joules of heat. What is the final
temperature of the water?
Answer:
.3044
q = mass x specific heat x (Tfinal-Tionitial)
q = -7500. Substitute and solve for Tfinal
Explanation:
Please mark brainliest and have a great day!
Which of the following is not a characteristic of S waves?
Answer:
C) travel through solids and liquids
Explanation:
Though S waves can travel through solids, they cannot travel through liquids.
HELP!!!!!!!!!!!!!!!!
Hyy mate......
Here is your answer ......
➡️⏺️Oxygen⏺️⬅️1️⃣Name: Oxygen
2️⃣State : non-metal
3️⃣Family:Oxide
4️⃣Protons: 8
Electron:8
Neutron: 8
Hope it will help you...
Thanks for asking....
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A 50.0-mL sample of gas is cooled from 119ºC to 80.0ºC. If the pressure remains constant, what is the final volume of the gas?
Answer:
45.03 mL.
Explanation:
We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and P are constant, and have different values of T and V:(V₁T₂) = (V₂T₁).
V₁ = 50.0 mL, T₁ = 119ºC + 273 = 392 K,
V₂ = ??? mL, T₂ = 80ºC + 273 = 353 K.
∴ V₂ = (V₁T₂)/(T₁) = (50.0 mL)(353 K)/(392 K) = 45.03 mL.
To find the final volume of a gas sample when cooled from 119ºC to 80.0ºC at constant pressure, we use Charles's Law, resulting in an approximate final volume of 45.0 mL.
To solve this, we use Charles's Law, which states that for a given mass of gas at constant pressure, the volume is directly proportional to its temperature in Kelvin.
First, convert the temperatures from Celsius to Kelvin:
Final temperature (T₂): 80.0ºC + 273.15 = 353.15 K
Using Charles's Law (V₁/T₁ = V₂/T₂):
Initial volume (V₁) = 50.0 mL
392.15 K / 50.0 mL = 353.15 K / V₂
Rearrange to solve for the final volume (V₂):
V₂ = (50.0 mL × 353.15 K) / 392.15 K
V₂ ≈ 45.0 mL
So, the final volume of the gas is approximately 45.0 mL.
Many stereo speaker cables are made of copper wire surrounded by rubber. The electricity travels down the copper portion of the cable while the rubber protects you from being "zapped" by the electricity. Which physical property explains the difference in ability of copper and rubber to transmit electricity?
A.
density
B.
ductility
C.
color
D.
conductivity
Answer:
d
Explanation:
rubber barely conducts electricity
Answer:
D: Conductivity
Explanation:
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