Sirius is a blue-white star with a surface temperature of about 9800 K. What is most likely the mass of Sirius? 1.0 solar mass 1.4 solar mass 2.0 solar mass 12 solar mass
The answer is actually 2.0 solar masses.
How many molecules (not moles) of nh3 are produced from 5.81×10−4 g of h2? express your answer numerically as the number of molecules?
elements can be broken down through ______ processes.
which atoms exist as diatomic molecules?
What is the balanced chemical equation for the reaction used to calculate ΔH∘f of SrCO3(s)?
If fractional coefficients are required, enter them as a fraction (i.e. 1/3). Indicate the physical states using the abbreviation (s), (l), or (g) for solid, liquid, or gas, respectively without indicating allotropes. Use (aq) for aqueous solution.
Answer:
[tex]Sr(s)+C(s)+ 3/2O_{2}(g)\rightarrow SrCO_{3}(s)[/tex]
Explanation:
The standard enthalpy of formation (ΔH°f) is defined as the enthalpy change which accompanies the formation of 1 mole of a compound from its constituent elements all of which are in their standard states i.e. either solid (s), liquid (l) , gas (g) or the aqueous phase (aq).
Strontium carbonate (SrCO3) contains 3 elements:
-Strontium (Sr) where the standard state is solid(s)
- Carbon (C) where the standard state is again a solid (s)
- oxygen (O) where the standard state is the gas phase (g)
The balanced chemical equation for the standard enthalpy of formation (ΔH°f) for SrCO3 would be:
[tex]Sr(s)+C(s)+ 3/2O_{2}(g)\rightarrow SrCO_{3}(s)[/tex]
what is a saturated solution in your own words, please!!!!
Answer:
A saturated solution is a solution that has the maximum amount of solute that is capable of being dissolved
Explanation:
What is the most important requirement for all living things? water carbon dioxide light vitamins
Water is the essential thing, since we are talking about ALL living organisms. The most basic and important necessity they all share is the need to hydrate.
Which defines reaction mechanism in chemistry? the mixing of two or more liquids to form a solution the steps in a chemical reaction in which products result from reactants a process in which a product is changed from one physical form to another intermolecular forces that cause attraction or repulsion between nearby particles?
Answer:
the answer is B : the steps in a chemical reaction in which products result from reactants
Explanation:
Which one has more mass a bag of cotton balls or a bag of nails and explain
The equilibrium constant kc for the decomposition of phosgene, cocl2, is 4.63 10-3 at 527°c. cocl2(g) equilibrium reaction arrow co(g) + cl2(g) calculate the equilibrium partial pressure of all the components, starting with pure phosgene at 0.760 atm.
To determine the equilibrium partial pressures for the components of phosgene decomposition, we first establish the initial conditions and use the given equilibrium constant. We then set up an equation based on the changes at equilibrium and solve it to find the equilibrium partial pressures.
Explanation:Equilibrium Partial Pressure of Phosgene Decomposition ComponentsThe decomposition of phosgene (COCl2) into carbon monoxide (CO) and chlorine gas (Cl2) can be observed using the equation COCl2(g) ⇌ CO(g) + Cl2(g). From the problem, we can consider an initial pressure of 0.760 atm of COCl2 and a negligible amount of CO and Cl2. Given that the equilibrium constant (Kc) for this reaction is 4.63 x 10-3, we can set up an equation derived from the equilibrium expression: Kc = (PCO x PCl2)/PCOCl2.
As the reaction proceeds, the pressure of COCl2 decreases by an 'x' amount to establish equilibrium, and the pressure of CO and Cl2 increases by the same 'x' amount. Thus, at equilibrium: Kc = ((0.760-x)x)/x. Solving this equation for 'x', we can obtain the equilibrium partial pressure of all components in the system.
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As you read the passage below, highlight all of the biotic factors. Bobby is helping his dad make dinner. They are having steak and boiled potatoes. Bobby’s dad asks him to get the potatoes from the pantry. Bobby cannot reach the shelf, so he uses a wooden stool to stand on. While Bobby’s dad finds a knife to cut the steak, Bobby puts the potatoes in a pot of boiling water. While the steak and potatoes cook, Bobby and his dad set out ceramic dishes on the table and some sour cream for the potatoes
Answer:
A,B,C,E, and H
Explanation:
Unagi
In the passage, the biotic factors are the steak and the potatoes, which are derived from living organisms - an animal and a plant, respectively. Other mentioned items like the wooden stool and ceramic dishes are abiotic factors and, therefore, not highlighted as biotic. The importance of biotic factors, such as potatoes, in ecology and human history is also discussed, including their role in the Irish potato famine.
Explanation:The student has asked to highlight all of the biotic factors in the given passage. In ecology, biotic factors are the living components of an environment, which include organisms from the same or different species. Examples of biotic factors in the scenario provided would be the steak, since it comes from an animal, and the potatoes, as they are plant-based food. Both of these are derived from living organisms, making them biotic factors.
Contrastingly, abiotic factors refer to the non-living components such as sunlight, soil, and water which are also mentioned in the background information provided. The wooden stool, boiling water, and ceramic dishes mentioned in the passage are examples of abiotic factors since they are non-living and do not directly represent former living organisms.
To put it in context, potatoes as mentioned in the scenario, are significant biotic factors in human diets and ecosystems, as they are photosynthetic autotrophs and interact with abiotic factors like soil nutrients, water, and sunlight to grow. The Irish potato famine, caused by late blight of potato (Phytophthora infestans), illustrates the importance of biotic interactions, particularly how diseases can impact plant populations and subsequently human societies.
A student is told that both energy and mass must be conserved in every chemical reaction. She measures the mass of Hydrochloric acid and a zinc strip separately. She then places the zinc strip into the acid and bubbles form as the zinc looks like it disappears. The combined mass afterward is less than the original. Which of these can explain this result? A) The student must have not measured the mass correctly. B) The zinc disappears and therefore the mass is less after the reaction. C) This is not a chemical reaction so the conservation laws do not apply. D) The bubbles indicate that a gas is created and mass is loss as it escapes from the container.
can someone please help. A sucrose solution is prepared to a final concentration of 0.170M . Convert this value into terms of g/L, molality, and mass % (molecular weight, MWsucrose = 342.296g/mol ; density, ρsol′n = 1.02g/mL ; mass of water, mwat = 961.8g ). Note that the mass of solute is included in the density of the solution,
The solubility of a gas in a liquid is _____. proportional to the square root of the pressure of the gas above the liquid unrelated to the pressure of the gas above the liquid inversely proportional to the pressure of the gas above the liquid directly proportional to the pressure of the gas above the liquid
Answer:
directly proportional to the pressure of the gas above the liquid
Explanation:
Henry’s law,
Sg = k Pg
where Sg, k and Pg are solubility of the gas, Henry’s constant and partial pressure of the gas respectively.
According to Henry’s law the amount of gas that can dissolve in a liquid is directly proportional to the partial pressure of the gas above the liquid.
The combustion of titanium with oxygen produces titanium dioxide: ti (s) + o2(g) â tio2 (s) when 1.000 g of titanium is combusted in a bomb calorimeter, the temperature of the calorimeter increases from 25.00 °c to 60.00 °c. in a separate experiment, the heat capacity of the calorimeter is measured to be 9.84 kj/k. the heat of reaction for the combustion of a mole of ti in this calorimeter is ________ kj/mol.
Answer:
The heat of reaction for the combustion of a mole of Ti in this calorimeter is -16,557.69 kJ/mol.
Explanation:
Mass of titanium = 1.000 g
Moles of titanium =[tex]\frac{1 g}{47.87 g/mol}=0.0208 mole[/tex]
Heat capacity of the calorimeter ,c= 9.84 kJ/K
Initial temperature of the calorimeter ,T=25°C =298 K
Final temperature of the calorimeter ,T'= 60°C = 333 K
Heat gained by calorimeter = q
[tex]q=c\times \Delta T= 9.84 kJ/K\times(333K-298 K)=344.4 kJ[/tex]
Heat of combustion released when 1 g of titanium = -344.4 kJ
Heat if released that is why negative sign is used.
In 1 g of titanium = 0.0208 mole
Heat of combustion of 0.0208 moles of titanium = -344.4 kJ
Heat of combustion of 1 moles of titanium:
[tex]\frac{-344.4 kJ}{0.0208}=-16,557.69 kJ[/tex]
The heat of reaction for the combustion of a mole of Ti in this calorimeter is -16,557.69 kJ/mol.
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The addition of hydrochloric acid to a silver nitrate solution precipitates silver chloride according to the reaction:
AgNO3(aq)+HCl(aq)→AgCl(s)+HNO3(aq)
When you combine 70.0mL of 0.185M AgNO3 with 70.0mL of 0.185M HCl in a coffee-cup calorimeter, the temperature changes from 23.16∘C to 24.25∘C.
Calculate ΔHrxn for the reaction as written. Use 1.00 g/mL as the density of the solution and C=4.18J/g⋅∘C as the specific heat capacity.,
Due to the formation of hydrogen bonds, _____ is highly soluble in water.
Due to the formation of hydrogen bonds, methanol is highly soluble in water.
What is Hydrogen bonding?Hydrogen bonding may be defined as a type of electrostatic force of attraction between a hydrogen atom that is significantly bonded to a more electronegative atom such as Nitrogen, Oxygen, and fluorine. There are generally two types of hydrogen bonding that exist in nature.
Intermolecular Hydrogen bonding: occurs between two separate molecules.Intramolecular Hydrogen bonding: occurs between the two different atoms of the same molecules.The molecules of water typically are polar in nature. Due to this, the hydrogen of one water molecule significantly forms a hydrogen bond with the oxygen of the same or different water molecules.
Water is an extensive framework of hydrogen bonds. This also leads to the methanol solubility in water due to hydrogen bonding between methanol and water molecules.
Therefore, methanol is highly soluble in water, due to the formation of hydrogen bonding.
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How many protons, neutrons, and electrons are in a neutral atom with the symbol 41Ca
A) 20 protons, 21 neutrons, 21 electrons
B) 20 protons, 21 neutrons, 20 electrons
C) 21 protons, 21 neutrons, 20 electrons
D) 41 protons, 0 neutrons, 41 electrons
There are 20 protons, 21 neutrons,20 electrons are in a neutral atom with the symbol 41Ca.
Explanation:
Given:
The neutral atom with symbol 41Ca
To find:
The numbers of protons, neutrons, and electrons.
Solution:
The given symbol of an atom is Ca which means that the given atom is of calcium.
The atomic number of calcium = 20
The atomic number of atom = Number of protons in an atom
The number of proton in a given calcium atom = 20
The given atom is neutral which means that an equal number of protons and electrons will be present.
The number of electrons = Number of protons = 20
The number of electrons in a given calcium atom = 20
The mass number of an atom is a sum of the number of neutrons and the number of protons
The number of neutrons = n
In the given symbol of calcium atom, the mass number of calcium is also given which is 41.
The mass number of the calcium atom = 41
[tex]41=n+20\\n=41-20=21[/tex]
The number of neutrons = 21
The number of neutrons in a given calcium atom = 21
There are 20 protons, 21 neutrons,20 electrons are in a neutral atom with the symbol 41Ca.
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MEDAL, please help me understand.
Which best describes the oxidizing agent in this reaction?
Cl2(aq) + 2Brmc003-1.jpg(aq) mc003-2.jpg 2Clmc003-3.jpg(aq) + Br2(aq)
Bromine (Br) is the oxidizing agent because it gains an electron.
Bromine (Br) is the oxidizing agent because it loses an electron.
Chlorine (Cl) is the oxidizing agent because it gains an electron.
Chlorine (Cl) is the oxidizing agent because it loses an electron.,
Answer:
c
Explanation:
At STP, two 5.0-gram solid samples of different ionic compounds have the same density. These solid samples could be dominated by their
The correct answer is option (b). At STP, two 5.0-gram solid samples of different ionic compounds have the same density. These solid samples could be dominated by their crystal structures.
A) Molar masses: The molar mass of a compound refers to the mass of one mole of that substance. While the molar mass affects the mass of the compound, it does not directly determine the density unless the volume occupied by the same mass of different compounds is considered.
B) Crystal structures: The crystal structure refers to the arrangement of ions in a solid. If two ionic compounds have the same density, it is likely that their ions are packed in a similar manner, resulting in the same volume for the same mass. The crystal structure determines how closely the ions are packed together, which directly influences the density.
C) Ionic charges: While ionic charges influence the electrostatic forces between ions, they do not directly determine the density of a solid. The arrangement of ions (crystal structure) has a more direct impact on density than the charges of the ions themselves.
D) **Solubilities**: The solubility of a compound refers to how well it dissolves in a solvent, such as water. This property does not affect the density of the solid form of the compound.
The complete question is:
At STP, two 5.0-gram solid samples of different ionic compounds have the same density. These solid samples could be dominated by their __________.
A) molar masses
B) crystal structures
C) ionic charges
D) solubilities
Which property could be a dominant factor for these solid samples to have the same density?
Sodium tends lose a single electron in natural settings. Based on what you know, what are two other elements that tend to do the same thing?
Question 4 options:
sodium and magnesium
hydrogen and helium
beryllium and boron
potassium and rubidium
**I said D**,
Answer:
D. potassium and rubdium
How can you determine the number of moles of a contained gas when the pressure, volume, and temperature are known values?
Under STP conditions (1 atm and 0°C), 1 mole of an ideal gas occupies 22.4 liters.
The Ideal Gas Law is a fundamental equation that relates the pressure (P), volume (V), and temperature (T) of an ideal gas to the number of moles (n) of the gas. The law is expressed by the equation:
[tex]\[ PV = nRT \][/tex]
where:
- [tex]P[/tex] is the pressure of the gas, typically measured in atmospheres (atm),
- [tex]V[/tex] is the volume of the gas, usually measured in liters (L),
- [tex]n[/tex] is the number of moles of the gas,
- [tex]\( R \)[/tex] is the ideal gas constant, which has a value of 0.0821 L·atm/(mol·K) when the pressure is in atm and the volume is in liters, and
- [tex]\( T \)[/tex] is the temperature of the gas in Kelvin (K).
To find the number of moles [tex]n[/tex], we can rearrange the Ideal Gas Law equation to solve for [tex]n:[/tex]
[tex]\[ n = \frac{PV}{RT} \][/tex]
For example, if we have a gas at a pressure of 1 atm, a volume of 22.4 L (which is the molar volume of an ideal gas at STP), and a temperature of 273 K (0°C), we can calculate the number of moles as follows:
[tex]\[ n = \frac{(1 \text{ atm})(22.4 \text{ L})}{(0.0821 \text{ L·atm/(mol·K)})(273 \text{ K})} \][/tex]
[tex]\[ n = \frac{22.4}{0.0821 \times 273} \][/tex]
[tex]\[ n \approx 1 \text{ mol} \][/tex]
This calculation confirms that under STP conditions (1 atm and 0°C), 1 mole of an ideal gas occupies 22.4 liters.
for: rate=k[A]^x determine the value of x if the rate doubles when [A] is doubled; and if the rate quadruples when [A] is doubled.,
To determine the value of x in the rate law expression rate = k[A]^x we set up equations based on the given conditions and solve for x. However, the provided conditions imply two different values for x which suggests a misunderstanding since the reaction order cannot have two different values under the same conditions.
Explanation:The question is asking to determine the value of x in the rate law expression rate = k[A]^x given that the rate doubles when the concentration of A is doubled and the rate quadruples when the concentration of A is doubled. This can be determined by substituting the given conditions into the rate law expression and solving for x.
For the first condition, when [A] is doubled, the rate doubles. This means if the initial rate is R with an initial concentration [A], the rate with 2[A] will be 2R. Plugging this into the rate law, we get: 2R = k(2[A])^x. Dividing both sides by R we get 2 = 2^x, which implies that x = 1.
For the second condition, we are told if [A] is doubled, the rate quadruples. So, we expect 4R = k(2[A])^x. By the same reasoning, 4 = 2^x, which gives us x = 2.
However, this presents a contradiction since we cannot have an x equal to 1 and an x equal to 2 at the same time. Therefore, it's possible that some additional information is missing or has been misinterpreted. The scenario where the rate doubles or quadruples accordingly implies that the order x is directly proportional to the factor by which the rate increases. Based on the conditions provided, two different orders are suggested which is not possible for a single reaction under the same conditions.
Determine the entropy change when 1.80 mol of HBr(g) condenses at atmospheric pressure?
Answer:
Entropy change = -168.3 J/mol-K
Explanation:
The entropy change is expressed as:
[tex]DeltaS = \frac{DeltaH}{T}[/tex]
For HBr, the enthalpy of condensation = -19.27 kJ/mol
Temperature T = -67 C = 273 - 67 = 206 K
Therefore, the entropy change when 1 mol of HBr condenses is:
= [tex]\frac{-19.27 kJ/mol}{206 K} =0.0935 kJ/mol-K = -93.5 J/mol-K[/tex]
Thus for the given 1.80 mol of HBr the entropy change would be:
[tex]= 1.80 mol * -93.5 J/mol- K = -168.3 J/mol-K[/tex]
The entropy change when 1.80 mol of HBr(g) condenses at atmospheric pressure can be determined using the equation ΔS = -ΔH/T, where ΔH is the enthalpy change and T is the temperature.
Explanation:The entropy change when a substance condenses can be calculated using the following equation:
∆S = -∆Hvap / T
where:
∆S is the entropy change (J/K·mol)
∆Hvap is the enthalpy of vaporization (kJ/mol)
T is the temperature of condensation (K)
The enthalpy of vaporization of HBr is -19.27 kJ/mol. The temperature at which HBr condenses at atmospheric pressure is its boiling point, which is -67°C. Converting this temperature to Kelvin, we get:
T = -67°C + 273.15 K = 206.15 K
Plugging in these values, we get:
∆S = -(-19.27 kJ/mol) / 206.15 K = 0.09348 kJ/K·mol
Converting kJ to J, we get:
∆S = 0.09348 kJ/K·mol * 1000 J/kJ = 93.48 J/K·mol
Therefore, the entropy change when 1.80 mol of HBr(g) condenses at atmospheric pressure is -168.3 J/K·mol.
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• describe/recognize the molecular structure of water. • define these terms o matter o element o atom • know and be able to define the subatomic particles found in atoms. • define atomic number and atomic mass. • be able to determine the reactivity of an element by how many electrons are in the valence shell. • distinguish between ionic, covalent, polar covalent, nonpolar covalent and hydrogen bonds. • state the difference between a compound and a molecule.
If exactly 50 ml of a 0.050m solution of hydrochloric acid is added to exactly 50 ml of 0.050m ammonia, what is the ph of the resulting solution?
How is most carbon dioxide transported from tissues to the lungs? view available hint(s) how is most carbon dioxide transported from tissues to the lungs? as carbonic acid. as carbon dioxide gas. as bicarbonate ions (hco3−). as protons (h+)?
During photosynthesis, plants absorb energy from sunlight, they take in water from the soil using their roots, and they take in carbon dioxide from the atmosphere. What is produced in the leaves of plants, in addition to oxygen?
Answer:
Sugar
Explanation:
Sugar Transport. Sugars, which are formed by the plant during photosynthesis, are an essential component of plant nutrition. Like water, sugar (usually in the form of sucrose, though glucose is the original photosynthetic product) is carried throughout the parts of the plant by the vascular system. Welcome.
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Which term describes the degree to which an element attracts electrons? which term describes the degree to which an element attracts electrons? electronegativity. polarity. oxidation. reduction?
Electronegativity is the term which describes the degree to which an element attracts electrons in a bond. It's different from electron affinity, which involves energy exchange when an isolated atom acquires an electron. More nonmetallic elements, due to their high electronegativities, can form covalent compounds called oxyacids.
Explanation:The term that describes the degree to which an element attracts electrons is known as electronegativity. This is a property of atoms that determines how the shared electrons in a bond are distributed. For example, in a polar covalent bond, the electrons are shifted toward the more electronegative atom, and this atom is the one that acquires a partial negative charge.
There is, however, an important distinction between electronegativity and electron affinity. The electron affinity of an element refers to the energy released or absorbed when an isolated gas-phase atom acquires an electron. But electronegativity involves attraction of electrons within a bond.
High electronegativities are characteristic of the more nonmetallic elements. These elements can form covalent compounds containing acidic -OH groups that are called oxyacids.
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