Answer:
[tex]\boxed {\boxed {\sf 8.0 \ M \ NaCl}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter, therefore the formula is:
[tex]molarity= \frac{moles \ of \ solute}{lites \ of \ solution}[/tex]
There are 2.0 moles of solute or sodium chloride dissolved in 0.25 liters of water or solution.
moles of solute = 2.0 mol NaCl liters of solution = 0.25 LSubstitute these values into the formula.
[tex]molarity= \frac{ 2.0 \ mol \ NaCl}{0.25 \ L}[/tex]
Divide.
[tex]molarity=8 \ mol \ NaCl / L[/tex]
Molarity is measured in molars or M. 1 molar is equal to 1 mole per liter, so our answer is equal to 8 molars.
[tex]molarity= 8 \ M \ NaCl[/tex]
The original measurements of moles and liters have 2 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. There are no numbers to round, so we add a 0 in the tenths place.
[tex]molarity= 8.0 \ M \ NaCl[/tex]
The molarity of the solution is 8.0 M NaCl.
What is said to have happened to the electrons in an atom in its ground state absorbs a quantum of energy from light
Answer:
The electron from the ground state to occupy a next energy level. In this case,we say that the electron is excited
Identify the group number and generic outer electron configuration for a neutral main‑group element with the following two Lewis dot symbols.
X with 1 dot on the top, bottom and right
X with 1 dot on all sides
Answer: Answer to #1 is 3A and ns2np1
Answer to #2 is 4A and ns2np2
Explanation:Group number is the number of valance electrons and generic outer electron configuration has to add up to equal the number of valance electrons
The element in the first diagram is in group 13 while the element in the second diagram is in group 14.
The Lewis structure of an atom of an element is a representation of the number of valence electrons on the outermost shell of the atom of that element. Every group of elements have a generic electron configuration which represents the number of valence electrons contained by atoms of elements in that group.
In the first diagram, the element X belongs to group 3A(13) and has a generic outer electron configuration, ns2np1. In the second diagram, the element X is in group 4A(14) and has outer electron configuration ns2np2.
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What is the concentration of a solution formed by diluting 25.0 ml of a 3.8M glucose solution to 250ml
Explanation : số mol glucose 3.8M là :
n = Cm . V = 3.8 . 25 =95
=> Cm khi pha loãng = [tex]\frac{n}{V}[/tex] = [tex]\frac{95}{250}[/tex] = 0.38M
According to molar concentration, the concentration of a solution formed by diluting 25.0 ml of a 3.8 M glucose solution to 250 ml is 0.38 M.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions given it is calculated as M₁V₁=M₂V₂,on substitution, M₂=3.8×25/250=0.38 M.
Thus, the concentration of a solution formed by diluting 25.0 ml of a 3.8 M glucose solution to 250 ml is 0.38 M.
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9. Which is true of a radioisotope that is used to date rock formations?
Answer:
Radiometric dating or radioactive date is the method that uses radioisotope to date the formation of a rock. The age of the rocks will be determined.
Explanation:
Radioactive deterioration is a natural process and results from the unstable atomic core, which releases bits and parts.
These radioactive particles are released as (there are many types). This decline process results in a more equilibrated nucleus, which makes the atom stable when the number of protons and neutrons balances.
This radioactivity is suitable for dating, as a radioactive "parent" item is constantly decaying into a stable "daughter" element.
A single mineral grain or a whole rock may be dated. There are techniques by which the sample is excited in a nuclear reactor and then measured with a mass spectrometer. The isotope (such as in the argon-argon scheme).
Others put mineral grains under a special microscope, fir in the grains with an ionising laser beam that releases the mineral and the isotopes.
The isotopes are measured by a mass spectrometer inside the same machine (an example of this is SIMS analysis).
how can we separate the sugar from sugar solution
What is the mass of the block of iron that has 10 cm 5 cm and 2 centimeters
Answer:
787.4g
Explanation:
The dimensions of the iron block is given as follows;
L = 10cm, B = 5cm, H = 2cm
Volume = L × B × H
Volume = 10 × 5 × 2
Volume = 100cm³
Density of iron metal = 7.874 g/cm³
Using the formula;
Density = mass/volume
Mass = density × volume
Mass = 7.874 × 100
Mass of iron = 787.4g
what’s the name of the organic molecule
Answer:
hexane
Explanation:
This is a 6- carbon hydrocarbon with no multiple bonds or any functional groups (such as -OH). Thus, the prefix 'hex' refers to the 6 carbons and 'ane' refers to the molecule being an alkane.
Naming molecules:
Number of carbons
• pentane: 5 carbons
• hexane: 6 carbons
• heptane: 7 carbons
• octane: 8 carbons
• nonane: 9 carbons
Functional groups (for 6- carbons molecules)
• Alkene (C=C): hexene
• Alcohol (-OH): hexanol
• Alkyne (C≡C): hexyne
Emission and abpsorption spectra from a given atom or molecule can tell us: Group of answer choices the composition of substances, even at great distances away, by identifying its uniques spectral fingerprint. The motion toward or away from us based on the doppler effect and corresponding red shift or blue shift The temperature of an object by using Wien's Law. All of the above.
Answer:
The motion towards or away from us based on the Doppler effect and corresponding red shift or blue shift.
Explanation:
The emission and absorption spectra demonstrates the lines where light has been absorbed by the atoms. The spikes can be observed due to atoms releasing photons at those wavelengths. Infrared and ultra violet waves can be observed during spectroscopy.
How many moles are in 68 liters of H2S gas at STP? :}
Answe:
Explanation:
số mol của H2S là : 68/22.4=3.03 nha
Which of the following oxides is amphoteric oxide?
A)Na2O
B)Al2O3
C)MgO
D)SO2
Answer:
absolutely B because Al2O3 could react with axit and bazo
Explanation:
Answer:
"Aluminum oxide, beryllium oxide, tin oxide, zinc oxide all are amphoteric. They have reactions as both a base and an acid."
Explanation:
I need help with question 2
Answer:
here's the answer to your question
which elements total number of electrons is equal to the number of core electrons in barium(Ba)?
Answer:
Xenon
Explanation:
The core electrons of an element are the electrons that do not take part in the chemical reactions of the element
The electronic configuration of barium Ba is presented as follows;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s²
2+2+6+2+6+2+10+6+2+10+6
The valence electrons of boron are the 6s² electrons
The core electrons of boron are the; 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶
The electronic configuration of xenon, Xe, which is the previous noble element before barium, is presented as follows;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ which is the same as the core electrons of barium
Therefore, the total number of electrons in xenon is equal to the number of core electrons in barium
Tenemos una disolución de HNO3 cuya pureza es del 65% y tiene una densidad de 1.32 g/mL. ¿Cuál es la molaridad de la disolución? PM HNO3 = 63.0 g/mol.
Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].
El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.
Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.
Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.
Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:
[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]
Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].
Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:
[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]
En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]
Aprende más sobre la molaridad:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultsWhat information does the percent composition of an atom in a molecule
give?
A. The relative number of atoms one element contributes to a
molecule
B. The relative amount of mass an atom contributes to a molecule
C. The total mass that element contributes to a molecule
D. The total number of atoms of that element in a molecule
C.
This is basically the definition of percent composition which is how much mass a element contributes to a specific molecule.
Answer: B.
Explanation:
the relative amount of mass an atom contributes to a molecule
what is precipitating ???
anyone please tell me how to delete an I'd
Explanation:
Desposition of solid matter in a solution
4.1 shows a plant cell. g For Examiner's Use n. C D Fig. 4.1 (i) Name the type of plant cell shown in Fig. 4.1. [1]
Answer:
palisade cell due to presence of chloroplasts
When 120 g of carbon reacts completely with 320 g of oxygen the mass of carbon dioxide formed will be?
Calculate the amount of mole(s) of CoF2 required to react with 12.8 moles of HCI.
CoCl2 + 2HF --> CoF2 + 2HCI
Explanation:
here's the answer to your question
Describe all the types of chemical reactions with example.
PLZ HELP ME WITH MY WORK
Which is an example of using a physical model to represent an earthquake?
O A. Using a computer to measure what happens during an earthquake
O B. Thinking of an earthquake as someone jumping on the bed next to YOU
C. Calculating the movement of the ground during an earthquake
O D. Shaking a cake that has models of buildings on it SUBMIT
Answer:
D. Shaking a cake [...]
Explanation:
None of the rest are actual physical models representing earthquakes.
Hope that's right! :D
How the amount of acid rain caused by the burning of fossil fuels can be reduced ?
Answer:
The amount of acid rain caused by the burning of fossil fuels can be reduced by creating nitrogen oxides in the process of burning coal and other fossil fuels, some power plants are changing the way they burn coal. A great way to reduce acid rain is to produce energy without using fossil fuels. Instead, people can use renewable energy sources, such as solar and wind power.
Research about the factors that influence the climates of these places including effects of Sun on the climate. Please give me fast i need help
Answer:
Distance from the sea, ocean currents, direction of prevailing winds, shape of the land, latitude, temperature, air pressure and distance from the equator.
Explanation:
Distance from the sea, ocean currents, direction of prevailing winds, shape of the land, latitude, temperature, air pressure and distance from the equator are the factors that influence the climates of any region. These factors has a great impact on the climate of a region, those regions which are nearer to the equator experiences hot climate whereas those regions which are far from the equator having cold climatic conditions.
What are you most likely to observe when an endothermic reaction is taking place?
Answer:
An endothermic reaction is when heat is needed by the reaction, so it draws heat from its surroundings, making them feel cold. Just like a ice pack.
Can someone do these? Brainliest included
Answer:
Explanation:
6. p⁺ e⁻
Ca²⁺ 20 18
F⁻ 9 10
O²⁻ 8 10
Na⁺ 11 10
7. Physical properties of matter are properties that can be measured or observed without matter changing to an entirely different substance. These include odor, boiling point, melting point, density, electrical conductivity and heat conductivity.
Separation of mixture:
Chromatography involves solvent separation on a solid medium.
Distillation takes advantage of differences in boiling points.
Evaporation removes a liquid from a solution to leave a solid material.
Filtration separates solids of different sizes.
Funnel partitioning with solvents. Solvent dissolves one component but not the other.
8.Bulk Elements => Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur & Phosphouous
Microminerals are those minerals needed in less than 100 mg quantities. Trace minerals or trace elements are usually needed in microgram quantities. Microminerals include iron, zinc, copper, iodine, fluoride, chromium, cobalt, selenium, manganese, and molybdenum.
Diatomic Molecules => H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂
9. Electron Configurations
Na: 1s²2s²2p⁶3s¹ => valence = 3s¹
N: 1s²2s²2p³ => valence = 2s²2p³
Al: 1s²2s²2p⁶3s²3p¹ => valence = 3s²3p¹
Valence is the highest principle quantum number (or, principle energy level ~ ring) in the electron configurations.
10.moles of glucose = 450g/180.16 g/mol =2.50 moles
C₂H₆O₂ = 2(12) + 6(1) + 2(16) = 24 + 6 + 32 = 62 g/mole
What does a pH of 7 say about a solution?
O A. The solution is at equilibrium.
B. The solution is neutral.
O C. The solution is acidic.
O D. The solution is basic.
Answer:
Its's B
The Solution is neutral
Explanation:
25.Which of the following reaction will not take place?
A. Zn+ FeSO4 → ZnSO4 + Fe
C. Fe + NiSO4 → FeSO4 + Ni
B. 2Al + 3MgSO4→ Al2(SO4)3 + 3Mg D.
Cu + 2AgNO3 → Cu(NO3)2 + 2Ag
Answer:
B
Explanation:
because Mg is stronger than Al
burning sugar is a chemical change give reason?
Burning a sugar cube is a chemical change. Fire activates a chemical reaction between sugar and oxygen. The oxygen in the air reacts with the sugar and the chemical bonds are broken. Burning sugar leads to reaction of sugar with oxygen in air and leads to formation of carbon dioxide and water. The change is irreversible and is thus a chemical change
The graph shows the volume of a gaseous product formed during two trials of a reaction. A different concentration of reactant was used during each trial, whereas the other factors were kept constant.
A graph is shown with two graph lines sloping upwards. The title on the x axis is Time and the title on the y axis is Amount of Product. The graph line with a steeper slope is labeled Trial X and the other is labeled Trial Y.
Which of the following statements explains which trial has a lower concentration of the reactant? (5 points)
Trial X, because the final volume of product formed is lower than Trial Y.
Trial X, because this reaction was initially fast and later stopped completely.
Trial Y, because the reaction was initially slow and later stopped completely.
Trial Y, because the volume of product formed per unit time is lower than Trial X.
Answer:
Trial Y, because the volume of product per unit time is lower than Trial X
Explanation:
In the chemistry experimental setup, the amount of gaseous product formed by the different concentration of the trials are measured and the result is plotted on a graph
The given graph, shows;
The vertical, y-axis = The amount of product
The horizontal, x-axis = Th time of the reaction
Trial X = The graph line with a steeper slope
Trial Y = The graph line
Increase in the concentration f the reactants, increases the number of collisions, and therefore, the number of effective collisions that gives the product also increases, and the overall rate of reaction increases
A more concentrated reactants produce more product in a shorter time (yield more product in less time) than a less concentrated one, and a more concentrated reactant would have a steeper slope and therefore produce more volume of the product in less time than a less concentrated reactant, which produces a lower volume in the same time
Therefore, the trial that has a lower concentration of the reactant is Trial Y, because the volume of product per unit time is lower than Trial X.
Answer:
There ya go
Explanation:
3. A typical peanut butter and jelly sandwich contains 360 kcal, of which 160
kcal comes from fat. Given 1 kcal = 4.2 kJ, how many J of fat would there be
in one PB&J sandwich?
Explanation:
here's the answer to your question
Please help I have been stuck on this problem for a couple hours and can't figure it out
Answer:
11.92 Liters O₂(g) at STP
Explanation:
For most stoichiometry problems, if one will convert all given data into moles, solve by rxn ratios, then finish by converting to needed dimensions to complete problem.
2Pb(NO₃)₂ => 2PbO + 4NO₂ + O₂
Given 237.5 grams PbO formed in reaction = 237.5 g/223.2 g/mole = 1.064 mole PbO
From equation ratios, moles O₂ formed = 1/2(moles PbO) = 1/2(1.064 moles O₂) = 0.532 mole O₂
0.532 mole O₂ = 0.532 mole x 22.4 liters/mole at STP = 11.91756272 liters (calculator answer) ≅ 11.92 liters O₂ at STP (4 sig.figs. based on given 237.5g PbO)
