Answer:
I'm assuming you're talking about something like a regular housekey, in which case there are numerous things you can describe!
Its mass: how much it weighs, times the gravity of the system.
Its color: is it silver-colored, or gold, etc.?
Its volume: you could probably calculate this, though it would be hard because it's not a traditional shape, I assume.
Its density: this is mass/volume. It means how many of the atoms are in a given space; how tightly packed the atoms are.
Its tendency to rust / its specific combination of metals or alloys: is it made of copper, tin, steel.. and these are all things that can rust to varying degrees.
At standard pressure (760 mm) water boils at 100C. A vacuum pump is used to reduce the ambient pressure above water under a sealed bell jar. By reducing the pressure, the boiling point is lowered so that the water begins to boil at room temperature. What is the approximate pressure at which water boils at room temperature (22C)?
Answer:
601mmHg.
Explanation:
Step 1:
Data obtained from the question.
Initial pressure (P1) = 760mmHg
Initial temperature (T1) = 100°C = 100°C + 273 = 373K
Final temperature (T2) = 22°C = 22°C + 273 = 295K
Final pressure (P2) =..?
Step 2:
Determination of the new pressure at which the water will boil.
The new pressure on the at which the water will boil can be obtained as follow:
P1/T1 = P2/T2
760/373 = P2/295
Cross multiply to express in linear form
373 x P2 = 760 x 295
Divide both side by 373
P2 = (760 x 295) / 373
P2 = 601mmHg
Therefore, the new pressure at which the water will boil is approximately 601mmHg.
Answer:
C. 18-20 mm
Explanation:
Benzene, C6H8, has an enthalpy of fusion = 10.19 kJ/mol. Calculate the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?
1107 Joule is the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C.
What is energy?In order to perform work and to produce heat and light, energy must be delivered to a body or to an external physical system. Energy is a quantitative property. Energy is a preserved resource; according to the rule of conservation of energy, energy can only be transformed from one form to another and cannot be created or destroyed.
A moving object's kinetic energy, an object's potential energy, an object's elastic energy, chemical energy linked to chemical reactions, electromagnetic radiation's radiant energy, and the internal energy of a thermodynamic system are examples of common kinds of energy.
mole of benzene = 85.2/78.11 =1.09mol
1 mole of benzene requires 10.19 kJ/mol energy
1.09 mole of benzene requires 1.09× 10.19 kJ/mol = 11.107kJ/mol energy
= 1107 Joule energy
Therefore, 1107 Joule is the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C.
To learn more about energy, here:
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How much energy is required to heat 250 grams of water from 20.0°C to 80.0°C? The heat capacity of water is 4.186 J/g°C
Q=mc∆T
Answer:
62,790J
Explanation:
Q=mcT
= 250g*4.186J/gc*80-20
=250*4.186*60=62,790J
are energy levels and orbitals the same thing?
Answer:
No they are not
Explanation:
Energy levels of electrons have fixed distance from the nucleus of an atom where electrons may be found.
orbitals is the path that electrons revolve
When 100.g Mg3N2 reacts with 75.0 g H2O, 15.0 g of NH3 is formed. What is the % yield?
Answer:
% yield = 44.5 %
Explanation:
Step 1: Data given
Mass of Mg3N2 = 100.0 grams
Mass of H2O = 75.0 grams
Mass of NH3 = 15.0 grams
Molar mass of Mg3N2 = 100.95 g/mol
Molar mass of H2O = 18.02 g/mol
Molar mass of NH3 = 17.03 g/mol
Step 2: The balanced equation
Mg3N2 + 3H2O → 3MgO + 2NH3
Step 3: Calculate moles
Moles = mass / molar mass
Moles Mg3N2 = 100 grams / 100.95 g/mol
Moles Mg3N2 = 0.99 moles
Moles H2O = 75.0 grams / 18.02 g/mol
Moles H2O = 4.16 moles
Moles NH3 = 15.0 grams / 17.03 g/mol
Moles NH3 = 0.88 moles
Step 4: Calculate the limiting reactant
For 1 mol Mg3N2 we need 3 moles H2O to produce 3 moles MgO and 2 moles NH3
Mg3N2 is the limiting reactant. It will completely be consumed (0.99 moles)
H2O is in excess. There will react 3*0.99 = 2.97 moles
There will be produced 2*0.99 = 1.98 moles of NH3
Step 5: calculate mass of NH3
Mass of NH3 = moles NH3 * molar mass NH3
Mass NH3 = 1.98 moles * 17.03 g/mol
Mass of NH3 = 33.7 grams
Step 6: Calculate the % yield
%yield = (actual yield/ theoretical yield) * 100 %
% yield = (15.0 grams / 33.7) * 100 %
% yield = 44.5 %
The percentage yield of ammonia in the given reaction has been 44.44%.
The balanced chemical reaction can be:
[tex]\rm Mg_3N_2\;+\;3\;H_2O\;\rightarrow\;3\;MgO\;+\;2\;NH_3[/tex]
The moles can be given as:
Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]
Moles of [tex]\rm Mg_3N_2[/tex] = [tex]\rm \dfrac{100}{100.95}[/tex] molMoles of [tex]\rm Mg_3N_2[/tex] = 0.99 mol
Moles of [tex]\rm H_2O[/tex] = [tex]\rm \dfrac{75}{18.02}[/tex]Moles of [tex]\rm H_2O[/tex] = 4.16 mol
Moles of [tex]\rm NH_3[/tex] = [tex]\rm \dfrac{15}{17.03}[/tex]Moles of [tex]\rm NH_3[/tex] = 0.88 mol
The limiting reactant can be:
From the balanced equation for 3 moles of water, there has been 1 mole of magnesium nitrite. So, for 4.16 moles of water, there will be 1.38 moles of [tex]\rm Mg_3N_2[/tex]. Since the amount of [tex]\rm Mg_3N_2[/tex] has been completely consumed in the reaction, [tex]\rm Mg_3N_2[/tex] has been the limiting reactant.
So, the moles of ammonia produced =
1 moles [tex]\rm Mg_3N_2[/tex] = 2 moles ammonia.
0.99 moles [tex]\rm Mg_3N_2[/tex] = 0.99 [tex]\times[/tex] 2 moles [tex]\rm NH_3[/tex]
0.99 moles [tex]\rm Mg_3N_2[/tex] = 1.98 moles of ammonia.
The theoretical yield of ammonia = 1.98 moles
The actual yield of ammonia = 0.88 mol.
% Yield of Ammonia = [tex]\rm \dfrac{Actual\;yield}{Theoretical\;yield}\;\times\;100[/tex]
% Yield of Ammonia = [tex]\rm \dfrac{0.88}{1.98}\;\times\;100[/tex]
% Yield of Ammonia = 44.44 %
For more information about percentage yield, refer to the link:
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A college student ran out of salt and pepper to season his eggs with. All of the stores he went to was out of salt so he took it upon himself to make his own. He used copper (II) chloride and sodium nitrate to produce copper (II) nitrate and sodium chloride. The equation for this reaction is shown: __CuCl2+ __NaNO3__Cu(NO3)2+ __NaCl. Identify the coefficients by balancing theequation and tell what type of reaction it is. a.1, 2, 1, 2; single replacementb.2, 4, 2, 4, decompositionc.1, 2, 1, 2; double replacementd.1, 2, 3, 4; combustion
Answer:
B
Explanation:
I’m not really great at chemistry but I truly tried my best
In some areas of the world, deserts are expanding into places that were once forests. During this process, some of the forest trees will die off because of the change in climate.
But, some of the trees may survive this process. What adaptation would give a tree a chance to survive this environmental change?
A) The growth of limbs that are skinnier and longer.
B) The use of cones to protect and eventually spread seeds.
C) The type of root system that can grow deep into the ground.
D) Increased hardness of the wood in the tree that allows it to grow higher, and absorb more sunlight.
Answer:
i would say (c)
Explanation:
Answer:c
Explanation:
What is the definition of density
How compact a certain object or person is
Answer:
Density is a measure of mass per unit of volume.The average density of an object equal its total mass divided by its total volume.
why did early astronomers believe in the geocentric model?
Pulverized coal pellets, which may be approximated as carbon spheres of radius ro= 1 mm, are burned in a pure oxygen atmosphere at 1450 K and 1 atm. Oxygen is transferred to the particle surface by diffusion, whereit is consumed in the reaction C + O2CO2. The reaction rate is first order and of the form NO2’’= -k1CO2 (ro), where k1= 0.1 m/s. Neglecting changes in ro, determine the steady-state O2molar consumption rate in kmol/s. At 1450 K, the binary diffusioncoefficient for O2inCO2is 1.71 x 10-4m2/s.
Answer:
Explanation:
SO; If we assume that:
P should be the diffusion of oxygen towards the surface ; &
Q should be the diffusion of carbondioxide away from the surface.
Then the total molar flux of oxygen is illustrated by :
[tex]Na,x = - cD_{PQ}\frac{dy_P}{dr} +y_P(NP,x + N_Q,x)[/tex]
where;
r is the radial distance from the center of the carbon particle.
Since ;
[tex]N_P,x = - N_Q, x[/tex] ; we have:
[tex]Na,x = - cD_{PQ}\frac{dy_P}{dr}[/tex]
The system is not steady state and the molar flux is not independent of r because the area of mass transfer [tex]4\pi r^{2}[/tex] is not a constant term.
Therefore, using quasi steady state assumption, the mass transfer rate [tex]4\pi r^{2}N_{P,x}[/tex] is assumed to be independent of r at any instant of time.
[tex]W_{P}=4\pi r^{2}N_{P,x}[/tex]
[tex]W_{P}=-4\pi r^{2}cD_{PQ}\frac{dy_{P}}{dr}[/tex]
= constant
The oxygen concentration at the surface of the coal particle [tex]yP,R[/tex] will be calculated from the reaction at the surface.
The mole fraction of oxygen at a location far from pellet is 1.
Thus, separating the variables and integrating result into the following:
[tex]W_{P}\int_{R}^{\infty} \frac{dr}{r^{2}}=-4\pi[/tex]
[tex]r^{2}cD_{PQ}\int_{y_{P,R}}^{y_{P,\infty }}dy_{P}[/tex]
[tex]-W_{P}\frac{1}{r}\mid ^{\infty }_{R}= -4\pi cD_{PQ}(y_{P,\infty }-y_{P,R})[/tex]
[tex]=> W_{P}= - 4\pi cD_{PQ}(1-y_{P,R})R[/tex]
The mole of oxygen arrived at the carbon surface is equal to the mole of oxygen consumed by the chemical reaction.
[tex]W_{P} = 4 \pi R^2R"[/tex]
[tex]W_{P}= 4\pi R^{2}k_{1}"C_{O_{2}}\mid _{R}[/tex]
[tex]W_{P}= 4\pi R^{2}k_{1}"c y _{P,R}[/tex]
[tex]-4\pi cD_{PQ}(1-y_{P,R})R= - 4\pi R^{2}k_{1}"c y _{P,R}[/tex]
[tex]y_{P,R}=\frac{D_{PQ}}{D_{PQ}+Rk_{1}}[/tex]
[tex]y_{P,R}=\frac{1.7 \times 10^{-4}}{1.7\times 10^{-4}+10^{-3}\times 0.1}[/tex]
[tex]\mathbf{= 0.631}[/tex]
Obtaining the total gas concentration from the ideal gas law; we have the following:
where;
R= [tex]0.082m^3atm/kmolK[/tex]
[tex]c=\frac{P}{RT} \\ \\ c=\frac{1}{0.082\times 1450} \\ \\ = 0.008405kmol/m^3[/tex]
The steady state [tex]O_2[/tex] molar consumption rate is:
[tex]W_{P}= -4\pi cD_{PQ}(1-y_{P,R})R[/tex]
[tex]W_{P}= -4\pi (0.008405)(1.7\times 10^{-4})(1-0.631)(10^{-3})[/tex]
[tex]W_{P}= - 6.66\times 10^{-9}kmol/s[/tex]
1. Energy is required for chemical
reactions to take place. What form of
energy is used in cooking?
Balance these chemical equations mg(s)_ + _N2(g) = _mg3N2
Answer:
[tex]3 Mg(s) + N_2(g) = Mg_3N_2(s)[/tex]
Explanation:
The valance of magnesium atom is [tex]+2[/tex]
While the valence of nitrogen atom is [tex]- 3[/tex]
Let us first write the first half-reactions
[tex]Mg ---> Mg^{2+} + 2e^{-}[/tex]
The second half reaction is
[tex]2N + 6e^- -----> N_2[/tex]
Adding the above two reactions and writing the final reaction, we get -
[tex]Mg + N2 = Mg_3N_2[/tex]
The balance equation is
[tex]3 Mg(s) + N_2(g) = Mg_3N_2(s)[/tex]
Please help, lol :)) <--------------
Answer:
I has 5 valance electrons it wants 10 and 3 bonds
Explanation:
What types of reactions is shown below? check all that apply 2H2O2–>2H2O+O2
A) synthesis
B) decomposition
C) combustion
Answer:
Type of reactions :
Decomposition (O is seperated)Pleasee help me (15 points)
Answer:
Full moon.
Explanation:
This diagram shows a full moon because the sunlight is shining directly onto the side of the moon facing the earth in this instance.
Answer:
It is A
Explanation:
Choose the transition metal among the following which has only single ionic charge ?
A. Silver (Ag)
B. Chromium (Cr)
C. Iron (Fe)
D. Copper (Cu)
Please tell what is the answer and if possible explain me...
Answer:
Silver (Ag)
Explanation:
The electronic configuration of copper is shown below;
[Kr]4d10 5s1
We can see that there is only one 5s1 electron. Hence Ag^+ tends to display a pseudo noble gas configuration. This pseudo noble gas configuration explains why silver is prevalent in the +1 oxidation state.
The other transition metals have many stable oxidation states found in nature. Chromium is observed both in +3 and +6 oxidation states. Iron is found in +2 and +3 oxidation states and copper is mostly stable in the +2 oxidation state since the +1 oxidation state readily disproportionate.
Hence silver tends to have only a single ionic charge for reasons aptly stated above.
Equal volume of solutions with pH equal to 4 and pH equal to
10 are mixed. pH of the resulting solution is
Answer:7
Explanation:
H+ concentration of solutions is related to pH as -
[H+] = antilog(-pH)
For pH = 4,
[H+] = antilog(-4)
[H+] = 10^-4 M
For pH = 10,
[H+] = antilog(-10)
[H+] = 10^-10 M
When these 2 solutions are added, concentration of the mixture will be -
[H+] = √(10^-10 × 10^-4)
[H+] = √(10^-14)
[H+] = 10^-7 M
So now, pH of the mixture will be
pH = -log(10^-7)
pH = 7
A sample of gas occupies 15.0 liters at a pressure of 2.00 atmosphere and a temperature of 300. K. If the pressure is lowered to 1.0 atmosphere and the temperature is raised to 400. K, the volume of the gas sample would be?
Answer:
THE NEW VOLUME OF THE GAS SAMPLE IS 40 L AT 1 atm AND 400 K
Explanation:
Using general gas equation which combines Boyle's and Charles' law, the volume of the gas sample at the new pressure and temperature can be obtained.
P1V1/T1 = P2V2/T2
P1 = Initial pressure = 2 atm
V1 = Initial volume = 15 L
T1 = Initial temperature = 300 K
P2 = Final pressure = 1 atm
T2 = Final temperature = 400 K
V2 = Final volume = unknown
Substituting the values into the equation, we have;
V2 = P1V1T2 / P2 T1
V2 = 2 * 15 * 400 / 1 * 300
V2 = 12 000/ 300
V2 = 40 L
The new volume after the pressure was reduced to 1 atm and the temperature increased to 400 K is 40 L.
Which is associated with a fission reaction? *
6 points
hydrogen nucleii
radioactive waste
reactant with light mass
containment problem
Answer: Radioactive waste
Explanation:
The nuclear fission reaction consists of heavy atomic particles or heavy nucleus, like plutonium and uranium and in radioactive heavy metals. In the fission reaction the nucleus get split into equal masses of particles. This process is associated with release of large amount of energy. The fission of radioactive waste can cause deadly mutations in living beings.
4. All of the following are examples of natural causes of air pollution
except -
hurricans
factory emissions
forest fires
tornadoes
ANSWER PLEASE AND THANK YOU☺️(bless you btw)
Answer:
factory emissions
Explanation:
What two agents are the biggest proponents of chemical weathering?
Answer:
water and carbon dioxide
Explanation:
Chemical weathering is the process of changing the composition of a mineral in order to break it down. The two agents that are the biggest proponents of chemical weathering are water and carbon dioxide. Water is used in a process called Hydrolysis which uses it to break down substances such feldspar in granite rocks changing to clay. While Carbon Dioxide in the atmosphere dissolves in rainwater forming carbonic acid, which slowly dissolve rocks when it comes into contact with them.
Un compuesto tiene la siguiente composición en tanto por cien: 19,3% de Na, y 26,9% de S y 53,8% de O. Su peso molecular es 238.Calcula la fórmula molecular
Answer:
[tex]NaSO_{4}[/tex]
Explanation:
Asúmase que existen 100 gramos de compuesto, las cantidades molares de cada componente son, respectivamente: (Let assume that exist 100 grams of the composite, the molar quantities of each component are, respectively:)
Na
[tex]n = \frac{19.3\,g}{22.99\,\frac{g}{mole} }[/tex]
[tex]n = 0.839\,moles[/tex]
S
[tex]n = \frac{26.9\,g}{32.065\,\frac{g}{mole} }[/tex]
[tex]n = 0.839\,moles[/tex]
O
[tex]n = \frac{53.8\,g}{15.999\,\frac{g}{mole} }[/tex]
[tex]n = 3.363\,moles[/tex]
La fórmula molecular empírica es (The empirical molecular formula is):
[tex](Na_{0.839}S_{0.839}O_{3.363})_{1.192}[/tex]
[tex]NaSO_{4}[/tex]
How many grams of beryllium phosphate are produced when 38 grams of beryllium oxide reacts with iron (III) phosphate? Show your work.
3BeO + 2FePO₄ → Be₃(PO₄)₂ + Fe₂O₃
Answer: 305 g of [tex]Be_3(PO_4)_2[/tex] will be produced from 38 grams of beryllium oxide
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} BeO=\frac{38g}{25g/mol}=1.52moles[/tex]
[tex]3BeO+2FePO_4\rightarrow Be_3(PO_4)_2+Fe_2O_3[/tex]
According to stoichiometry :
3 moles of [tex]BeO[/tex] produce = 1 mole of [tex]Be_3(PO_4)_2[/tex]
Thus 1.52 moles of [tex]BeO[/tex] will produce =[tex]\frac{1}{3}\times 1.52=0.507moles[/tex] of [tex]Be_3(PO_4)_2[/tex]
Mass of [tex]Be_3(PO_4)_2=moles\times {\text {Molar mass}}=0.507moles\times 602g/mol=305g[/tex]
Thus 305 g of [tex]Be_3(PO_4)_2[/tex] will be produced from 38 grams of beryllium oxide
Find the heat produced from an 8.00 L cylinder of propane gas under 5.00 atm at 25.0 oC, if one mole of propane can produce 2220 kJ.
A. 4290 kJ
B. 0.0289 kJ
C. 877 kJ
D. 1.63 kJ
E. 5420 kJ
F. 1750 kJ
G. 8440 kJ
H. 1360 kJ
I. 37.2 kJ
J. 630 kJ
K. 266 kJ
L. 645 kJ
M. 2420 kJ
N. 7.36 x 10-4 kJ
Answer: 3597 kJ of heat
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 5.00 atm
V = Volume of gas = 8.00 L
n = number of moles = ?
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]25.0^0C=(25.0+273)K=298K[/tex]
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{5.00atm\times 8.00L}{0.0821 L atm/K mol\times 298K}=1.63moles[/tex]
As it is given :
1 mole of propane produces = 2220 kJ of heat
Thus 1.63 moles of propane produces = [tex]\frac{2200}{1}\times 1.63=3597kJ[/tex]
Thus 3597 kJ of heat is produced
Vaporization that takes place inside a liquid is called________.
Answer:
evaporation
Explanation:
Answer:
Boiling
Explanation:
When a substance transitions from liquid to gas, it's called evaporation if it's on the surface, and boiling if it's all throughout the liquid.
Picture boiling water in a pot: it starts on the bottom, and the bubbles go toward the top. Evaporation starts on the surface.
Calculate the Zn conc. of Zn/Zn++ // Cl/Cl- 0.1M Emf=2.21v
answers:
a)0.1M
b)0.2M
c)0.05M
d)0.15M
Thanks!
Answer:
Option a. = 0.01 M
Explanation:
To do this, we need to gather the data:
E = 2.21 V
[Cl⁻] = 0.1 M
And the Redox reaction taking place is the following:
Zn(s) + Cl₂(g) <-------> Zn²⁺(aq) + 2Cl⁻(aq) Q = [Zn] [Cl]²
E° Cl⁻/Cl₂ = 1.36 V
E° Zn/Zn²⁺ = -0.76 V
According to this, the expression to use will be the Nernst equation, and we can assume we are working at 25 °C, therefore, the Nernst equation will be:
E = E° - (0.059/n) logQ
E = E° - (0.059/n) ln([Cl⁻]² * [Zn²⁺]) (1)
From there, we can solve for Zn later.
First, we need to write the semi equation of oxidation and reduction, and get the standard potential of the cell:
Zn(s) --------> Zn²⁺(aq) + 2e⁻ E₁° = 0.76 V
Cl₂(g) + 2e⁻ -----------> 2Cl⁻(aq) E₂° = 1.36 V
---------------------------------------------------------------
Zn(s) + Cl₂(g) -------> Zn²⁺(aq) + 2Cl⁻(aq) E° = 0.76 + 1.36 = 2.12 V
Now, let's replace in (1) and then, solve for [Zn]:
2.21 = 2.12 - (0.059/2) log ([0.1]² * [Zn])
2.21 - 2.12 = -0.0295 log (0.01[Zn])
- 0.09 / 0.0295 = log (0.01[Zn])
-3.0508 = log (0.01[Zn])
10^(-3.0508) = 0.01[Zn]
8.8961x10⁻⁴ = 0.01[Zn]
[Zn²⁺] = 0.08896 M
This value can be rounded to 0.1 M. so the correct option will be option A.
What is thermal equilibrium?
A student claims that if she wanted to make a solution quickly, she should use small pellets instead of powder along with heating and stirring. Do you agree or disagree with the student's claim? I am confused on this so I would greatly appreciate anyone’s help.
Answer: Yes, the student is right, one should use pellets of the reactant should be heated and stirred for mixing properly.
Explanation:
In case of smaller particles the surface area that is being exposed increases and the due to this the reaction occurs faster.
Increasing the temperature of the temperature, increases the kinetic energy of the particles which helps in easy mixing of the particles.
The collision in between the particles also increase while stirring and thus the rate of reaction increases.
So, the heating and stirring is more preferred over powered reactant for making a solution quickly.
Given the equation for a system at equilibrium:
N2(g) + 3H2(g) <-> 2NH3(g) + energy
If only the concentration of N2(g) is increased, the concentration of
1. NH3(g) increases
2. NH3(g) remains the same
3. H2(g) increases
4. H2(g) remains the same
Answer: 1. [tex]NH_3[/tex] increases.
Explanation:
Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
For the given equation:
[tex]N_2(g)+3H_2(g)\rightleftharpoons 2NH_3(g)+energy[/tex]
If the concentration of [tex]N_2[/tex] is increased , according to the Le-Chatlier's principle, the reaction has to shift to right or forward direction. In order to do that the concentration of products has to increase.
Thus the concentration of [tex]NH_3[/tex] increases.
HELP ME SOLVE THIS PLEASE
Answer:
B. 47.3
Explanation: