Answer:
8.7 million species
Explanation:
Scientists have estimated that there are around 8.7 million species of plants and animals in existence.
the normal human eye responds to visible light of wavelength range from about 390 to 710nm. Determine the frequency range of the human eye.
Explanation:
=>7.7 x10¹⁴ to 4.2 x10¹⁴Hz
Explain what is meant by the term 'conservation of mass'.
Give your answer in terms of the atoms that take part in a chemical reaction
Answer:
Below
Explanation:
In a chemical reaction, per the law of conservation of mass, no atoms or subatomic particles will be created or destroyed; for example, H2O2 will decompose into H2 and O2, meaning no matter was created or destroyed.
A chemical engineer must be able to predict the changes in chemical concentration in a reaction. dC/dt = -kCn where C is chemical concentration and k is rate constant. Order of reaction is the value of n. The first order reaction that combines tert-butyl bromide and water to produce tert-butyl alcohol and hydrogen bromide is shown below; (CH3)3CBr + H2O (CH3)3COH +HBr From the experimental data, k was estimated to be k = 0.0537 (h -1 ). Determine concentration after 1 hour, if C(0) = 0.2 mol/L
Answer:
Explanation:
Consider the general chemical reaction
[tex]\mathrm{A} \ \overset{k}{\longrightarrow} \ \mathrm{product}[/tex] .
If [A] is the concentration of A (reactant) at any time t and n is the reaction order for the whole equation, the rate is then related to the concentration of reactant A with the following differential form of equation
[tex]Rate \ = \ -\displaystyle\frac{d[\mathrm{A}]}{dt} \ = \ k[\mathrm{A}]^{n}[/tex] .
where k is the rate constant.
*Note that the differential term [tex]\displaystyle\frac{d[\mathrm{A}]}{dt}[/tex] has a negative sign to denote that the concentration of A is decreasing over time t.
Since the chemical reaction between tert-butyl bromide and water is given to be a first-order reaction, hence n = 1, and the resulting differential equation becomes
[tex]Rate \ = \ -\displaystyle\frac{d[\mathrm{A}]}{dt} \ = \ k[\mathrm{A}]^{1} \ = \ k[\mathrm{A}][/tex]
To solve this first-order linear homogenous differential equation, the method of separation of variables can be used.
[tex]\-\hspace{1cm} \displaystyle\frac{d[\mathrm{A}]}{dt} \ = -\ k[\mathrm{A}] \\ \\ \-\hspace{0.5cm} \displaystyle\frac{1}{[\mathrm{A}]} \, d[\mathrm{A}] \ = -\ k \, dt \\ \\ \int\ {\displaystyle\frac{1}{[\mathrm{A}]} \, d[\mathrm{A}] \ = \ -\int {k} \, {dt}[/tex]
[tex]\ln{[\mathrm{A}]} \ = \ -kt \ + \ C \\ \\ \-\hspace{0.45cm} $[A]$ \ = \ e^{-kt \ + \ C} \\ \\ \-\hspace{0.45cm} $[A]$ \ = \ e^{-kt}e^{C} \ \ \ \ \ \ \ \ \ (e^{a \ + \ b} \ = \ e^{a}e^{b} \ \ \ \mathrm{by \ the \ law \ of \ indices})[/tex]
Since the term [tex]e^{C}[/tex] is a constant, let [tex]\alpha \ = \ e^{C}[/tex], hence [tex][\mathrm{A}] \ = \ \alpha e^{-kt}[/tex] or [tex]C \ = \ \alpha e^{-kt}[/tex] according to the question. Given that the initial concentration (t = 0) of tert-butyl bromide is 0.2 mol/L and k = 0.0537[tex]\mathrm{h^{-1}}[/tex], so
[tex]0.2 \ = \ \alpha e^{-0.0537 \ \times \ 0} \\ \\ 0.2 \ = \ \alpha \ \ \ \ \ (e^{0} \ = \ 1)[/tex]
Therefore, the rate equation is [tex]C \ = \ 0.2e^{-0.0537t}[/tex].
The concentration of tert-butyl alcohol after 1 hour is
[tex]C \ = \ 0.2e^{-0.0537 \ \times \ 1} \\ \\ C \ = \ 0.2e^{-0.0537} \\ \\ C \ = \ 0.190 \ \mathrm{mol/L} \ \ \ (3 \ \ \mathrm{s.f.})[/tex]
which of the following forces could be used in electronic devices?
spring
gravitational
applied
magnetic
Answer:
Explanation:
poop
how are homogeneous mixtures different from heterogeneous mixtures
Answer:
In Homogenous mixtures, the whole mixture is in the same phase whereas in Heterogeneous mixture, substances can be of two phases and layers may separate. ... Homogeneous mixture could be exemplified as a sugar solution or salt solution whereas Mixture of salt and sand could be used as an example of Heterogeneous mixture.
You have a block of an unknown metal. Which properties would be most helpful in determining what it is? If it could be
what is the approximate pH of a solution labeled 0.050 M HCLO ?
Answer:
It would be around 4.4 in PH
Explanation:
I hope this helped.
Heart, 5 stars, and Brainiest to first right answer!
Which two types of air masses would likely form a subtropical jet stream?
Warm and cool air masses meeting near the North Pole
Cool and warm air masses meeting near the equator
Multiple warm air masses meeting near the equator
Two or more cool air masses meeting near the South Pole
Answer:
Give person above me brainliest
Explanation:
what is the element found in all living matter.
Answer:
There are four elements that are found in all living animals, that are:
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N).
USCTIR ENFIK meaning?
Answer:
la branche de la mécanique concernée par le mouvement des objets sans référence aux forces qui provoquent le mouvement
Answer:
the features or properties of motion in an object.
You have 15 grams of of MgSO4, how
many moles of MgSO4 do you have?
A 0.125 Moles of MgSO4
B 0.75 Moles of MgSO4
C 7.5 Moles of MgSO4
D 15.88 Moles of MgSO4
Answer:
C 7.5 Moles of MgSO4
Explanation:
Nitric oxide (NO) from car exhaust is a primary air pollutant. Calculate the equilibrium constant for the reaction
N2(g) + O2(g) equilibrium reaction arrow 2 NO(g)
at 25°C using the data listed in the supporting materials.
Calculate the equilibrium constant at 1496°C, which is a typical temperature inside the cylinders of a car's engine after it has been running for some time. (Assume that both ΔrH° and ΔrS° are temperature independent.)
This problem is asking for the equilibrium constant at two different temperatures by describing the chemical equilibrium between gaseous nitrogen, oxygen and nitrogen monoxide at 25 °C and 1496 °C as the room temperature and the typical temperature inside the cylinders of a car's engine respectively:
N₂(g) + O₂(g) ⇄ 2 NO(g)
Thus, the calculated equilibrium constants turned out to be 6.19x10⁻³¹ and 9.87x10⁻⁵ at the aforementioned temperatures, respectively, according to the following work:
There is a relationship between the Gibbs free energy, enthalpy and entropy of the reaction, which leads to the equilibrium constant as shown below:
[tex]\Delta _rG=\Delta _rH-T\Delta _rS\\\\\Delta _rG=-RT ln(K)[/tex]
Which means we can calculate the enthalpy and entropy of reaction and subsequently the Gibbs free energy and equilibrium constant. In such a way, we calculate these two as follows, according to the enthalpies of formation and standard entropies of N₂(g), O₂(g) and NO(g) since these are assumed constant along the temperature range:
[tex]\Delta _rH=2*90.25 kJ/mol - (0 kJ/mol+0 kJ/mol)=180.5kJ/mol\\\\\Delta _rS=2*(0.211 kJ/mol*K)-(0.192kJ/mol*K+0.205kJ/mol*K)=0.025kJ/mol*K[/tex]
Then, we calculate the Gibbs free energy of reaction at both 25 °C and 1496 °C:
[tex]\Delta _rG_{25\°C}=180.5-(25+298.15)*0.025=172.42kJ/mol\\\\\Delta _rG_{1496\°C}=180.5-(1496+298.15)*0.025=135.65kJ/mol[/tex]
And finally, the equilibrium constants derived from the general Gibbs equation and Gibbs free energies of reaction:
[tex]K=exp(-\frac{\Delta _rG}{RT} )\\\\K_{25\°C}=exp[-\frac{172420 J/mol}{(8.3145\frac{J}{mol*K})(298.15K)} ]=6.19x10^{-31}\\\\K_{1496\°C}=exp[-\frac{135650J/mol}{(8.3145\frac{J}{mol*K})(1769K)} ]=9.87x10^{-5}[/tex]
Learn more:
(Gibbs free energy) https://brainly.com/question/15213613How many moles are in 500 g of P
Answer:
.....................
30.973761
How many electrons does chlorine need to gain in order to be like Argon ?
- 2 electrons
- 3 electrons
- 1 electron
How could you distinguish a compound from a mixture
Answer:
Compound are substances which can be formed by chemically combining two or more elements. Mixtures are substances that are formed by physically mixing two or more substances.Explain why aluminum does not react with potassium nitrate (KNO3) although it reacts with copper nitrate
Answer:
Potassium is more reactive than aluminium, so no reaction takes place. But aluminium is more reactive than copper, so it replaces the copper in copper nitrate
Explanation:More reactive metal compound + less reactive metal
-> no reaction
However
Less reactive metal compound + more reactive metal
-> more reactive metal compound + less reactive metal
This is called substitution reaction where the more reactive metal replaces the less reactive metal in the compound.
PLEASE HELP GIVING brainless
Answer:
An unbalanced force causes the object to change position.
Explanation:
An unbalanced force causes the object on which it is acting to accelerate, changing its position, speed, or direction due to equal forces on opposite sides.
14. Which has the lowest ionization energy?
A. beryllium (Be) B. strontium (Sr) Calcium (Ca) D. magnesium (Mg)
Answer: B. strontium
Explanation: This is due to electrons being further away from the nucleus in strontium.
Producers are the most numerous group in an ecosystem. Why?
-------------------------------------------------------------------------------------------------
Producers produce food energy for themselves and all the other levels. ⬜
Soil and temperature conditions in an ecosystem always favor producers. ⬜
As energy flows through the ecosystem, some energy is added at each step. ⬜
There is more room for small organisms than there is for large ones. ⬜
Answer:
The primary producer uses some of that energy. Because we lose energy each time we move up a trophic level, we have more producers than consumers, more herbivores than carnivores, more primary consumers than secondary consumers. See this Socratic answer for more detail.
Explanation:
Answer:
Producers produce food energy for themselves and all the other levels
Explanation:
One student made the incomplete diagram shown below to represent the relationship between Magma, Igneous Rocks, and Metamorphic Rocks.
Which of these is the correct next step to complete the diagram?
A. Put an arrow labeled deposition and lithification, pointing from Igneous Rocks to Magma.
B. Put an arrow labeled heat and pressure, pointing from Magma to Igneous Rocks.
C. Put an arrow labeled heat and melt, pointing from Metamorphic Rocks to Magma.
D. Put an arrow labeled cools and crystallizes, pointing from Igneous Rocks to Metamorphic Rocks.
Answer:
the answer is B
Explanation:
this shows the next step and shows how magma turns into igneous rocks by heat and pressure
Why do nonmetal atoms share electrons in covalent bonds
Answer:
pairs of electrons
Explanation:
covalent bondin occurs when pairs of electrons are shared by atoms.... nonmetal will readily form covalent bonds with other nonmetal in order to obtain stability.
In one to two sentences, describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).(2 points)
An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.
Intramolecular forces are the forces of attraction that hold atoms together within a molecule. Intramolecular forces require a high amount of energy to splits atoms or molecules in a chemical bonding.
Intermolecular forces are weaker forces of attraction that occur between molecules. They require lesser energy to splits molecules compared to intramolecular forces.
An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.
In the process, the energy required to change the state from ice to steam water is more than intermolecular forces.
Thus, we can conclude that this experiment shows that the intramolecular forces are stronger than the intermolecular forces.
Learn more about Intramolecular forces here:
https://brainly.com/question/13588164
true or false in a chemical reaction the same number of each type of atom will always be present before and after the reaction takes place
Answer:
True
Explanation:
True because of the law of conservation of mass, the same same amount of atoms will be on both sides of the reaction.
1. Here is a chemical equation: C2H2 + O2 → CO2 + H2O
• A Balance this chemical equation.
• B State what type of chemical reaction this is.
• C What will happen during this reaction besides just CO2 and H2O being released.
• D Discuss how your balanced chemical equation agrees with the law of conservation of mass.
2. Balance each of the reactions listed below. What type of reactions are they? Single-displacement, double-displacement, synthesis, decomposition, or combustion reaction.
• A Na + Cl2 → NaCl
• B Fe + O2 → FeO
Answer:
1) a) 2 C2H2 + 3O2 --> 2CO2 + 2H2O
b) Combustion Reaction
c) Bonds will be broken on the reactant side which will require energy.
d) It agrees with the law of conservation of mass because there are the same amount of molecules of each element on both sides of the equation, meaning mass was not created nor destroyed.
2) a) 2Na + Cl2 --> 2NaCl
Synthesis
b) 2Fe + O2 --> 2FeO
Synthesis
Hope this helps!
Explanation:
To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. Therefore, the balanced equation is
2 C[tex]_2[/tex]H[tex]_2[/tex]+ 3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+ 2H[tex]_2[/tex]O
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
a) 2 C[tex]_2[/tex]H[tex]_2[/tex]+ 3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+ 2H[tex]_2[/tex]O is the balanced equation
b)Reaction is a Combustion Reaction
c) energy is required for the breaking of bond.
d) It agrees with the law of conservation of mass as the number of atoms of each element on reactant and product side is same.
Therefore, the balanced equation is
2 C[tex]_2[/tex]H[tex]_2[/tex]+ 3O[tex]_2[/tex] [tex]\rightarrow[/tex] 2CO[tex]_2[/tex]+ 2H[tex]_2[/tex]O
Learn more about the balanced equation, here:
https://brainly.com/question/7181548
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Please help due tomorrow
Giving Brainlesst
Answer:
Down arrow:
-a car comes to a stop when a traffic light turns red
Up arrow:
-race car accelerates when a race begins
Circle:
-car driving 45 mile per hour down straight road
Explanation:
and i think the car going around a bend would be an up arrow
Which element(s) would you expect to behave similarly to Gadolinium? What properties of would you expect to be the same, what would be different?
The elements in the lanthanide series are similar to gadolinium.
The periodic table is arranged in groups and periods. Elements in the same group have similar properties. At the bottom row of the periodic table lies a group of elements that have unique properties called the lanthanides. This is where Gadolinium belongs.
The elements in the lanthanide series such as europium and terbium are similar to gadolinium. The lanthanides are similar in chemical reactivity and appearance. However, the density of the metals differ because it increases with increase in atomic number.
Learn more: https://brainly.com/question/1415109
What is chlorine iodine ?
Answer:
Chlorine Iodine is a compound made out of one Chlorine molecule and one Iodine molecule
Explanation:
What is the function of the nervous system? What is the basic unit of the nervous system?
#Nova
Answer:
The basic unit of the nervous system is a nerve cell or neuron. The nervous system transmits signals between the brain and the rest of the body, this way, the nervous system's activity controls the ability to move, breathe, see, and think.
Explanation:
Have a great rest of your day
#TheWizzer
Please help me in this question about series circuit and pararell circuit
Explanation:
it is a parallel circuit.
hope this helps you.
what are nanofluids and how they work?
Answer:
What is nanofluids?
Nanofluids are engineered suspensions of nanometer-sized solid particles in a base fluid. Suspending small solid particles in the energy transmission fluids can improve their thermal conductivity and provides an effective and innovative way to enhance their heat transfer characteristics significantly.
How nanofluids work?
Nanofluid refers to the dispersion of metal or non-metal nano-powder into traditional heat exchange media such as water, alcohol, and oil to prepare a uniform, stable and high thermal conductivity. The traditional heat exchange medium has a low thermal conductivity and has been unable to meet the growing demand for industrial engineering heat exchange. The thermal conductivity of some metal or non-metal nanoparticles is often hundreds of times higher than that of heat-conducting media. For example, common silicon carbide nanoparticles have a thermal conductivity of 170-270 W/m•K. The researchers found that if the nanoparticles can be uniformly and stably dispersed in the heat transfer medium, the thermal conductivity of the nanoparticles will be greatly improved.