Answer:
element and compound.
Explanation:
reason
an element is a pure substance that cannot be broken down into simpler substances by any ordinary physical or chemical process.
and compound is a pure substance that consists of two or more elements held together in fixed proportions by natural forces called chemical bonds.
homogeneos and heterogenous mixtures are considered impure substances because they dont have a definite composition.
In chemistry, pure substances have been defined by matter that has characteristic properties. An element and compound are pure substances. Thus, options 1, and 2 are correct.
What are pure substances?Pure substances have been the matter that is characterized by the presence of a fixed chemical composition that cannot be physically separated by the processes like filtration, evaporation, etc.
Elements and compounds are pure substances as elements are not broken physically or chemically to form simple -small substances like zinc. Furthermore, compounds are formed by the combination of pure substances like water.
Homogeneous mixtures and heterogeneous mixtures are not pure substances as they lack fixed ratios and proportions that cannot be said to have definite composition.
Therefore, options 1 and 2. are elements and compounds are pure substances.
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Convert 300c into kelvin and Fahrenheit scale
Explanation:
300c = 1.8f+32= please calculate it yourself ☺
300c= k+273= 573k
if the ph of a solution is 9 then its pOH will be
Answer:
5.
Explanation:
The pOH is found by subtracting the pH by 14, because the pH and the pOH always add up to 14. So the pOH of a solution with the pH of 9 would be 5.
Hope this helps you out. :)
Which of the following samples contains the greatest number of atoms?
a. 9 mole of CO2 b. 10 moles of Xe
c. 11 moles of N2O d. 12 moles of CO
Answer:
12 moles of CO
Explanation:
According to Avogadro, one mole of a substance, contains the same number of elementary entities as 12g of carbon-12. Now the number of elementary entities (atoms, molecules, ions, particles etc) in any substance is given by the Avogadro's constant.
Now since 1 mole of a substance contains Avogadro's number of atoms, it means that the substance with the highest number of moles will have the highest number of atoms.
With this in mind we can see that 12 moles of CO is expected to contain 72.24 ×10^23 atoms of CO. Hence the answer.
Answer:
c. 11 moles of N2O.
Explanation:
Hello,
In this case, for each substance, we use the Avogadro's number to compute the number of atoms in the given sample:
a.
[tex]atoms \ C=9molCO_2*\frac{1molC}{1molCO_2} *\frac{6.022x10^{23}atoms\ C}{1molC} =5.4x10^{24}atoms\ C[/tex]
[tex]atoms \ O=9molCO_2*\frac{2molO}{1molCO_2} *\frac{6.022x10^{23}atoms\ O}{1molO} =1.1x10^{25}atoms\ O[/tex]
[tex]Total\ atoms=1.1x10^{25}+5.4x10^{24}=1.64x10^{25}atoms[/tex]
b.
[tex]atoms \ Xe=10molXe *\frac{6.022x10^{23}atoms\ Xe}{1molXe} =6.022x10^{24}atoms[/tex]
c.
[tex]atoms \ N=11molN_2O*\frac{2molN}{1molN_2O} *\frac{6.022x10^{23}atoms\ N}{1molN} =1.3x10^{25}atoms\ N[/tex]
[tex]atoms \ O=11molN_2O*\frac{1molO}{1molN_2O} *\frac{6.022x10^{23}atoms\ O}{1molO} =6.6x10^{24}atoms\ O[/tex]
[tex]Total\ atoms=1.3x10^{25}+6.6x10^{24}=2.0x10^{25}atoms[/tex]
d.
[tex]atoms \ C=12molCO_2*\frac{1molC}{1molCO_2} *\frac{6.022x10^{23}atoms\ C}{1molC} =7.2x10^{24}atoms\ C[/tex]
[tex]atoms \ O=12molCO_2*\frac{1molO}{1molCO_2} *\frac{6.022x10^{23}atoms\ O}{1molO} =7.2x10^{24}atoms\ O[/tex]
[tex]Total\ atoms=7.2x10^{24}+7.2x10^{24}=1.44x10^{25}atoms[/tex]
Thus, we notice 11 moles of N2O have the greatest number of atoms.
Best regards.
Carbon dioxide gas at a temperature of 35.0 C and a volume of 281mL. Determine the volume of the gas when the temperature of the gas is raised to 125 C if the pressure remains constant.
Answer: The volume of the gas when the temperature of the gas is raised to [tex]125^0C[/tex] is 363 ml
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]
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]V_1=281ml\\T_1=35.0^oC=(35.0+273)K=308K\\V_2=?\\T_2=125^0C=(125+273)K=398K[/tex]
Putting values in above equation, we get:
[tex]\frac{281}{308}=\frac{V_2}{398}\\\\V_2=363ml[/tex]
Thus the volume of the gas when the temperature of the gas is raised to [tex]125^0C[/tex] if the pressure remains constant is 363 ml
If everyone on the planet used the same amount of resources as an average American, what percent of the Earth would need to be used to support everyone?
Answer:
540% according to an article I read on BBC
Explanation:
Calcium carbonate decomposes at 12000 C to form carbon dioxide and calcium oxide. If 25 liters of carbon dioxide are collected at 12750 C, what will the volume of this gas be after it cools to 250 C?
Answer:
1L
Explanation:
Data obtained from the question include:
Initial volume (V1) = 25L
Initial temperature (T1) = 12750°C
Final temperature (T2) = 250°C
Final volume (V2) =..?
Next we shall convert from celsius to Kelvin temperature. This is illustrated below:
T(K) = T(°C) + 273
Initial temperature (T1) = 12750°C
Initial temperature (T1) = 12750°C + 273 = 13023K
Final temperature (T2) = 250°C
Final temperature (T2) = 250°C + 273 = 523K
Finally, we can obtain the new volume of the gas by using Charles' law equation as shown below:
V1/T1 = V2/T2
25/13023 = V2/523
Cross multiply to express in linear form
13023 x V2 = 25 x 523
Divide both side by 13023
V2 = 25 x 523 / 13023
V2 = 1L
Therefore, the new volume of the gas is 1L.
The volume of this gas after it cools to 250°C is equal to 0.490 Liter.
Given the following data:
Initial volume = 25.0 L Initial temperature = 12750°C Final temperature = 250°C
To determine the volume of this gas after it cools to 250°C, we would apply Charles's law:
Mathematically, Charles law is given by the formula;
[tex]\frac{V}{T} =k\\\\\frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex]
Where;
T is the temperature of an ideal gas. V is the volume of an ideal gas.Substituting the given parameters into the formula, we have;
[tex]\frac{25}{12750} = \frac{V_2}{250} \\\\25 \times 250 = 12750V_2\\\\6250 = 12750V_2\\\\V_2 = \frac{6250}{12750}[/tex]
Final volume = 0.490 Liter.
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Why are bacteria are able to evolve rapidly
A mixture of NO2 and N2O4 gas is at equilibrium in a closed container. These gases react with the equation 2NO2 ⇌ N2O4. What will happen if the size of the container is increased?
Answer:
Equilibrium shifts left making more NO2
Explanation:
In Le Chatlier's Principle, increase in volume shifts equilibrium to side with more moles so... there's 2 moles on left and 1 mole on right, so equilibrium shifts to left making more NO2
According to chemical equilibrium and Le-Chatlier's principle , the equilibrium will shift to left with increase in concentration of NO₂.
What is chemical equilibrium?Chemical equilibrium is defined as the condition which arises during the course of a reversible chemical reaction with no net change in amount of reactants and products.A reversible chemical reaction is the one wherein the products as soon as they are formed react together to produce back the reactants.
At equilibrium, the two opposing reactions which take place take place at equal rates and there is no net change in amount of the substances which are involved in the chemical reaction.At equilibrium, the reaction is considered to be complete . Conditions which are required for equilibrium are given by quantitative formulation.
Factors which affect chemical equilibrium are change in concentration , change in pressure and temperature and presence of catalyst.
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Please help, and solve the problem in kJ
Answer:
1. Exothermic.
2. Yes, released.
3. 38.65KJ of heat is released.
Explanation:
The equation for the reaction is given below:
2NO2 —> N2O4...... ΔH = –55.3KJ
1. The sign of the enthalpy change, ΔH tells whether the reaction is endothermic or exothermic. Since the sign of the enthalpy change, ΔH is negative, the reaction is exothermic.
2. The negative sign indicate that heat is released to the surrounding. Since the reaction is generally an exothermic reaction, 64.3g of NO2 will also release heat to the surroundings.
3. Molar mass of NO2 = 14 + (16x2) = 46g/mol
Mass of NO2 from the balanced equation = 2 x 46 = 92g.
From the balanced equation above:
92g of NO2 reacted to release –55.3KJ of heat.
Therefore, 64.3g of NO2 will react to release = (64.3 x –55.3)/92 = 38.65KJ of heat.
Therefore, 38.65KJ of heat is released.
a natural gas stove converts ... energy from burning into ... energy used to cook food.
Answer:
A natural gas stove converts chemical energy from burning into thermal energy used to cook food.
Explain whether a red apple is opaque or transparent and
why it appears red.
Sample Response: An apple is an opaque object because no light can pass through. The red apple reflects red light and absorbs all the other colors
which statement explains the energy term in this reaction
Answer:
Mass is lost due to the conversion of mass to energy
Explanation:
The question is not complete, the complete question is given as:
[tex]^{235}_{72}U +^{1}_{0}n[/tex] ⇒ [tex]^{140}_{56}Ba+^{93}_{36}Kr+3^{1}_{0}n+energy[/tex]
total mass equals 236.053 u total mass equals 235.868 u
Which statement explains the energy term in this reaction? (1) Mass is gained due to the conversion of mass to energy. (2) Mass is gained due to the conversion of energy to mass. (3) Mass is lost due to the conversion of mass to energy. (4) Mass is lost due to the conversion of energy to mass.
Answer: From Einstein’s equation E = mc², when a radioisotope element undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass.This mass lost is converted to energy.
The law of conservation of energy holds for this type of reaction (i.e the sum of mass and energy is remains the same in a nuclear reaction). Mass changes to energy, but the total amount of mass and energy combined remains the same before and after a nuclear reaction.
From the reaction above, the total decrease in mass = 236.053 - 235.868 = 0.185 u
What are the key characteristics of a combustion and redox reactions?
Answer:
Redox reactions have a reducing agent and a oxidizing agent
Explanation:the reducing agent is more reactive than the oxidizing agent
The atomic mass of iron is 55.85, and oxygen is 16.0. What is the mass of 6.02 × 1023 molecules of Fe2O3?
Answer:159.7grams
Explanation:
(55.85)2+(16)3
159.7grams
Answer:
The correct answer for plato/edmentum is C (159.7g)
PLEASE ANSWER ASAP!!! What is an example of a dilute solution that you can find at home?
Genetic material is carried the ______________ of a cell
1.vacuoles
2.cytoplasm
3.nucleus
4.cell membrane
Answer:
3. nucleus
Explanation:
The nucleus contains all the genetic information.
Hard water stains in sinks and showers can be caused by a buildup of solid calcium carbonate. These stains can be removed by bathroom cleaners containing acids such as aqueous hydrochloric acid, which reacts with the calcium carbonate to form carbon dioxide gas, aqueous calcium chloride and liquid water. a) Write a balanced equation for this reaction
Answer:
CaCO3 + 2HCl ---> CaCl2 + H2O + CO2
Explanation:
The reaction between solid calcium carbonate and a mineral acid such as aqueous HCl is a neutralization reaction and occurs with the evolution of CO2 gas.
The balanced equation is given below
CaCO3 + 2HCl ---> CaCl2 + H20 + CO2
The product CaCl2 is water soluble which accounts for why the stain is removed, while CO2 gas escapes away from the reaction surface.
Answer:
CaCO3(s) + 2HCl(aq) -------> CaCl2(aq) + 2CO2(g) + H2O(l)
Explanation:
CaCO3(s) + 2HCl(aq) -------> CaCl2(aq) + 2CO2(g) + H2O(l)
When an acid reacts with a metal carbonate a salt, carbon dioxide and water are formed. Hard water usually contain Ca^2+ in the form of Ca(HCO3)2. Minor heating causes CaCO3(calcium carbonate) to deposit on surfaces through which the hard water passes.
Calcium carbonate reacts with acids to produce a calcium salt, water and carbon dioxide: Calcium carbonate + Hydrochloric acid → Calcium chloride + Water + Carbon dioxide. The carbonate radical breaks up into carbon dioxide and oxygen; the oxygen binds with the acid's hydrogen ions to make water; and a solution of calcium chloride remains.
a substance has neither of fixed shape nor a fixed volume state whether it is a solid or liquid or gas
Hey!!!
The answer of your question is Gas.
Explanations:
Solid have a fixed shape and volume.
Liquid have a definite volume but no definite shape
Gas neither have fixed shape nor a fixed volume.
Hope it helps...
Good luck on your assignment
According to VSEPR theory, if there are two electron domains on a central atom, they will be arranged such that the angles between the domains are __________. a. 360° b. 120° c. 90° d. 180° e. 109.5°
Answer:
Option d is correct
Explanation:
The basis of the VSEPR model of molecular bonding is that to minimize repulsions, electron domains in the valence shell of an atom arrange on their own.
According to VSEPR theory, if there are two electron domains on a central atom, they will be arranged such that the angles between the domains are 180°
How many molecules are present in one mole of oxygen?
Answer: 6.022×10²³ molecules Oxygen
Explanation:
To get molecules, you will need Avogadro's number.
Avogadro's number: 6.022×10²³ molecules/mole
[tex]1mol O *\frac{6.022*10^2^3molecules }{1mol} =6.022*10^2^3 molecules[/tex]
Based on their number of valence electrons, which group of elements will gain two electrons by bonding with other atoms?
Question 1 options:
F, Cl, Br, I, At
N, P, As, Sb, Bi
O, S, Se, Te, Po
Be, Mg, Ca, Sr, Ba
Answer:
O, S, Se, Te, Po
Explanation:
O, S, Se, Te, Po are all elements found in group sixteen of the periodic table. Remember that the commonality between all the elements in the same group of the periodic table is that they all possess the same number of outermost electrons. All elements in the same group must have the same number of outermost electrons in their outermost shell.
Now, having six electrons in their outermost shell implies that they readily bond with two other atoms to complete their octet. In accordance with the octet rule. This explains why oxygen bonds with calcium by gaining two electrons in calcium oxide.
When may a scientific theory be revised
Answer:
A theory doesn’t change into a scientific law because of new or better evidence.
Explanation:
A theory will always remain a theory, and i law will remain a law. The reason being that theories and laws may differ on account of newfound countervailing evidence. Remember, theories and laws are very different from hypotheses.
What is the gram formula mass of Ca3(PO4)2
Answer:
it should be 310.18 g/mol :)
Which hydrocarbon has more than one possible structural formula?
Answer:
An alkane is a hydrocarbon in which there are only single covalent bonds. The simplest alkane is methane, with the molecular formula CH4.
Explanation:
Alkanes.
Name Heptane
Molecular Formula C7H16
Condensed Structural Formula CH3CH2CH2CH2CH2CH2CH3
Boiling Point (°C) 98.5
Hydrocarbons which are alkanes with 4 or more than 4 carbon atoms have more than one possible structural formula which is a type of chemical formula.
What is structural formula?Structural formula helps in identifying location of chemical bonds which are present between atoms in a molecule.It consists of symbols of elements for the atoms which are connected by short lines which actually represent the chemical bonds.
Structural formulae can be deduced from molecular formulae the fragment ions are studied in the mass spectrum.It is concerned with the valency which helps in determination of of how atoms a combine in a definite ratio.
Properties of molecules are much related with their structures. It helps in showing the arrangement of atoms in a three-dimensional space.
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which of the following is the best choice for presenting the relationship between atomic number and atomic mass?
Answer:
Atomic number is the number of protons in an atom
Atomic mass is the mass of an atom.
Explanation:
which of the following is the best choice for presenting the relationship between atomic number and atomic mass?
Atomic number is the number of protons in an atom
Atomic mass is the mass of an atom.
Existe una especie de pájaro en las islas Galápagos que puede ejercer una fuerza de 205N (Newton) con un pico para romper una semilla. Si su pico se desplazó 0,004m durante esta operación, ¿cuánto trabajo realiza el pájaro para conseguir la semilla? Ayuda por favor
Answer:
In order to calculate the work that the spike did, you have to respect the following equation:
WORK = FORCE X DISPLACEMENT X COS (0)
Explanation:
Work is measured in joules, and is the amount of energy a body needs to make a certain force over a certain distance.
In the case of this bird we would be calculating with the equation written up in the previous item the work that said animal would do to grind a seed.
Which nonmetal has the greatest potential to be oxidized
Answer:
Hydrogen
Explanation:
A reducing agent is a substance which gives up its electrons to become oxidized. Generally, metals are oxidized (reducing agents) while non-metals are reduced (oxidizing agents).
However, hydrogen which is a non-metal is usually oxidized in the presence of stronger oxidizing non-metals such as fluorine and oxygen.
Hydrogen thus, acts as a reducing agent by giving up its electrons to become oxidized. Even though among all non-metals, Hydrogen has the greatest potential to be oxidized, it is a poor reducing agent compared to reactive metals.
Please answer question 2.
1. What happens when you stir a spoonful of sugar into hot water?
2. When sugar or another substance is dissolved in water, it disappears from view and forms a homogeneous mixture with the water, also called a solution.
If you can’t see the sugar, how can you tell that it is there?
Answer:
The water tastes sweet, and it usually appears to be cloudy or not clear.
Explanation:
If nothing dissolves into the water, then it should be clear.
Answer:You can tell if the sugar is still there by boiling off the water and leaving the sugar behind in the container. Sugar is a solid, and therefore cannot evaporate, so when the water reaches boiling point, it will evaporate at a quicker rate than before (water evaporates at any temperature in liquid form; just not enough to be noticeable) and leave the container to become water vapour
Explanation: If you stir a spoonful of sugar into hot water, the sugar will dissolve in the hot water. When sugar or another substance is dissolved in water, it disappears from view and forms a homogeneous mixture with the water, also called a solution.
What is the electron configuration for potassium (K)?
1s22s22p63s43p43f1
1s22s22p63s23p63f1
1s22s22p63s43p44s1
1s22s22p63s23p64s1
Answer:
1s2 2s2 2p6 3s2 3p6 4s1
Explanation:
Aufbau's principal of the arrangement of electronic configuration states that, electrons fill orbitals of lower energy first before the higher energy. 1s2 2s2 2p6 3s2 3p6 4s2 3d10...
This arrangement explains the Aufbau's principal, hence, or therefore, the 1s2 2s2 2p6 3s2 3p6 4s1 is the right answer for the representation of the electron configuration for potassium (K).
hope this was helpful!
How many particles can be stored in a 4.0 L container at room temperature (23 C) and standard atmospheric pressure
(101.3 kPa)?
Answer: 9.91×10²³ particles
Explanation:
To find the amount of particles, you will need to use the Ideal Gas Law with what we are given.
Ideal Gas Law: PV=nRT
After we find moles, we can use Avogadro's number to convert to particles.
[tex]n=\frac{PV}{RT}[/tex]
P=101.3kPa=1.00 atm
V=4.0 L
T=23°C+273.15=296.15 K
R=0.08206 Latm/Kmol
[tex]n=\frac{(1.00 atm)(4.0 L)}{(0.08206Latm/Kmol)(296.15K)}[/tex]
[tex]n=0.164595 mol[/tex]
Now that we have moles, we can convert to particles.
[tex]0.164595mol*\frac{6.022*10^2^3 particles}{mol} =9.91*10^2^2 particles[/tex]
