Answer:
Molar mass of MgCl2 is 95 g/mol
Mg = 24 g/mol and Cl = 35.5 ×2 = 71 g/mol
moles = mass given/ molar mass
= 2.7/95 = 0.028 mol
volume = 250/1000 = 0.25 dm3 (ml is the same as dm3)
molarity of MgCl2 = moles/volume
= 0.028/0.25
= 0.112 mol/dm3
how many moles of carbonate are there in sodium carbonate
There are 0.566 moles of carbonate in sodium carbonate.
CALCULATE MOLES:The number of moles of carbonate (CO3) in sodium carbonate (Na2CO3) can be calculated by dividing the mass of carbonate in the compound by the molar mass of the compound. no. of moles of CO3 = mass of CO3 ÷ molar mass of Na2CO3Molar mass of Na2CO3 = 23(2) + 12 + 16(3)= 46 + 12 + 48 = 106g/molmass of CO3 = 12 + 48 = 60gno. of moles of CO3 = 60/106 no. of moles of CO3 = 0.566molTherefore, there are 0.566 moles of carbonate in sodium carbonate.Learn more about number of moles at: https://brainly.com/question/1542846
Please choose and answer 3 of the following 4 questions:
1. Rutherford and JJ Thompson both contributed to what we know about the structure of the atom. What experiments did they perform and how did it change what we know about the structure of the
atom? Furthermore, describe the structure of an atom using only words (no diagrams).
2. Electrons exist outside the nucleus on many different energy levels. When electrons lose energy, they emit waves that are found on the electromagnetic spectrum. What equation would you use to
find the wavelength or frequency of a wave, assuming you know the other value? What is the relationship between frequency and wavelength? What is the relationship between frequency and
energy?
3. Even though electrons move around constantly, scientists use electron configurations to give an "address" to a particular electron. What are the 4 shells that scientists use? How many electrons can
fit into each shell? How can you use the knowledge about these shells and the periodic table to determine the electron configuration of an element?
4. Suppose you know there is an element with an atomic number of 26 and a mass of 60. What do you know about this element? How many subatomic particles does it have? How can you tell?
Answer:
1. Rutherford performs the gold foil experiment while JJ Thompson performs cathode ray experiment. It was Rutherford's experiment that used positively charged alpha particles (He with a +2 charge) that were deflected by the dense inner mass of the nucleus (nucleus). The conclusion that could be drawn from this finding was that atoms were composed of an inner core that comprised the majority of the atom's mass and was positively charged in nature. The work of JJ Thompson using cathode ray tubes demonstrated that all atoms contain small negatively charged subatomic particles, also known as electrons. According to Thomson's conception of the atom, which had negatively-charged electrons buried inside a positively-charged "soup," the atom was made of plum pudding. Protons, electrons, and neutrons are the three fundamental particles that make up an atom. The protons (which are positively charged) and neutrons (which are neutrally charged) are found in the nucleus (center) of an atom (no charge). The electrons are contained inside the electron shells, which are the outermost parts of the atom (negatively charged).
2. Given that the frequency is 1/T, the equation linking wave speed, frequency, and wavelength is v=f t. The relationship between frequency and wavelength is inversely proportional. The wavelength of the wave with the highest frequency is also the shortest. When the frequency is doubled, the wavelength is cut in half. As a result, the wavelength to frequency ratio is the inverse of the frequency to wavelength ratio. When it comes to carrying energy, the frequency and amplitude of the waves are important factors to consider. The higher the frequency, the greater the amount of energy, and the larger the amplitude, the greater the amount of energy.
3. There are four shells that scientists used. First shell contains 2 electrons. Second shell consists of 8 electrons. Third shell has 18 electrons. Lastly, fourth shell has 32 electrons. 2 electrons can fit into each shell. If you want to compute an electron configuration, first split the periodic table into portions that represent the atomic orbitals, which are the locations where electrons are found. The s-block is represented by groups one and two, the d-block by groups three through twelve, the p-block by groups thirteen through eighteen, and the f-block by the two rows at the bottom.
Explanation:
That's the three questions I chose to answer. Hope it helps;)
What is a scientific law?
Answer:
Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. The term law has diverse usage in many cases across all fields of natural science.
Explanation:
I hope this helps
Answer:
Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. Scientific law differs from scientific theory. The main difference between a law and a theory is that a theory tries to explain the reasoning behind something that occurs in nature, whereas scientific laws are just descriptive accounts of how something occurs in nature.
activation energy in reaction is used to:
A- Overcome repulsion force between colliding molecules
B- Breaking bonds
C- Merge Valence electrons
D- All of them
Answer:
D — All of them
Explanation:
The activation energy in a reaction is the minimum amount of energy required for a chemical reaction to take place. Since all the options are processes in a chemical reaction, D should be the answer.
need help with this question, anybody ..
-20 points :)
How many moles is 7.78 x 1024
formula units of MgCl2?
How many moles is 7.78 x 1024
formula units of MgCl2?
answer: 7966.72
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, there are 0.49moles of MgCl[tex]_2[/tex] in 7.78 x 10²⁴atoms of MgCl[tex]_2[/tex] .
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.
we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number
mole =given number of atoms ÷ 6.022×10²³(Avogadro number)
given number of atoms of MgCl[tex]_2[/tex]= 7.78 x 10²⁴
Substituting the values
mole= 7.78 x 10²⁴÷ 6.022×10²³
mole = 0.49moles of MgCl[tex]_2[/tex]
So, there are 0.49moles of MgCl[tex]_2[/tex] in 7.78 x 10²⁴atoms of MgCl[tex]_2[/tex] .
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Why are naphthalene ball used to protect clothes from insects? How does it gradually decrease and ultimately disappear?
What is the pressure exerted by a force of 15.0 N over an area of 0.00372 m^2 ?
Explanation:
Pressure = Force/Area
therefore,
P = 15/0.00372
= 4.03 X10^³N/m²
LAST ATTEMPT! Covalent compound naming ! !!
Answer:
Name the non-metal furthest to the left on the periodic table by its elemental name.
Name the other non-metal by its elemental name and an -ide ending.
Use the prefixes mono-, di-, tri-.... to indicate the number of that element in the molecule.
im prolly wrong
How are oxidation-reduction reactions related to how you use energy?
Answer:
In oxidation reduction reactions, one species gets reduced by taking on electron(s) and another species gets oxidized by losing electrons. They also flow by a wire
Explanation:
K3PO4(aq)+MgCl2(aq)⟶
Answer:
6KCl(aq) + Mg3(PO4)2(s) ... balanced equation
Explanation:
is H2O polar or non polar?
Answer:
Explanation:
H2O is a polar molecule
Answer:
polar covalent molecule
Explanation:
the unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that water has two pole a positive and a negative.
Octane has a density of 0.703 g/ml. Calculate the mass of CO2(g) produced by burning one
gallon of octane. There are 3.79 liters to one gallon.
The mass of CO₂ gas produced during the combustion of one gallon of octane is 8.21 kg.
The given parameters:
Density of the octane, ρ = 0.703 g/mlVolume of octane, v = 3.79 litersThe mass of the octane burnt is calculated as follows;
[tex]m = \rho V\\\\m = 0.703 \ \frac{g}{ml} \times 3.79 \ L \ \frac{1000 \ ml}{L} \\\\m = 2,664.37 \ g[/tex]
The combustion reaction of octane is given as;
[tex]2C_8H_{18} + \ 25O_2 \ --> \ 16CO_2 \ + \ 18H_2O[/tex]
From the reaction above:
228.46 g of octane -------------------> 704 g of CO₂ gas
2,664.37 of octane --------------------> ? of CO₂ gas
[tex]= \frac{2,664.37 \times 704}{228.46} \\\\= 8,210.3 \ g\\\\= 8.21 \ kg[/tex]
Thus, the mass of CO₂ gas produced during the combustion of one gallon of octane is 8.21 kg.
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How many ml of a 2.903 M NaOH solution are needed to produce 500.0 ml of a 0.3344M solution?
Answer:
About 57.60 mL.
Explanation:
We can utilize the dilution equation:
[tex]\displaystyle M_1V_1 = M_2V_2[/tex]
Where M are the molarities of the solutions and V are the volumes of the solutions.
We want to determine the volume of a 2.903 M NaOH solution to mix in order to produce 500.0 mL of a 0.3344 M solution.
Substitute and solve for V₁:
[tex]\displaystyle \begin{aligned} (2.903 \text{ M})V_1 & = (0.3344 \text{ M})(500.0 \text{ mL}) \\ \\ V_1 & = 57.60\text{ mL} \end{aligned}[/tex]
In conclusion, 57.60 mL of a 2.903 M NaOH solution is needed.
A 0.1 M NaCl solution and a 0.2 M glucose solution are separated by a membrane that is impermeable to these solutes but is permeable to water. What will happen
nothing will happen
if you calculate the water potiential for both solutions
you get 2(0.1)(R)(T) and 1(0.2)(R)(T)
which is the same thing, so its isotonic.
How do the terms genotype and phenotype relate?
O Both are sets of alleles that define traits.
O An organism's phenotype leads to its genotype.
O An organism's genotype leads to its phenotype.
Both are terms for observable traits
Answer:
c is the
Explanation:
Which statement best explains the purpose of using a mole in the measurement of matter? It is commonly used as another unit of mass. It allows chemists to deal with a large number of atoms. It is used only for studying the properties of gases. It explains that substances with the same moles have the same mass.
Answer:
B) It allows chemists to deal with a large number of atoms.
Explanation:
On Edge 2022
The statement which best explains the purpose of using a mole in the measurement of matter is that it allows chemists to deal with a large number of atoms.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons .Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
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What you see as you look up at the night sky depends on the weather, the time of year, your location, and how dark your surroundings are. The
---
and stars are the celestial objects most people can see in the night sky.
the [moon] and stars are what most people see.
What equipment is generally used to make lyophilized medications suitable for administering to the patient? a) Test tubes or sterile ampules O b) Petri dishes and sterile droppers c) Sterile syringes or graduated cylinders d) Measuring cups and clean, warm water
If you have 3 g of each substance, which would take up the smallest volume?
Answer:
Explanation:
f the mass of an object is 35 grams and it takes up 7 cm3 of space, calculate the density.
34 pages
What type of material is half-life associated with?
Answer:
Radioactive material
Explanation:
2. A compound with an empirical formula of C2H3Br2 has a molar mass of 373.69 g/mol. What is
the molecular formula?
(The molar mass of C2H3Br2 = 186.85 g/mol)
E) C4H6Br4
А) C2H3Br2
B) CHBr
C) C6H9Br6 D) C4H6Br2
(0.5 Points)
A
Empirical is the simplest whole number ratio of elements in a compound. Molecular formula is n times the empirical formula, where n is integers 1,2,... The molecular formula is C[tex]_4[/tex]H[tex]_6[/tex]Br[tex]_4[/tex]. The correct option is option E.
What is empirical formula?Empirical formula gives the proportion of the element that is present in a compound. It does not give information about the actual number or the arrangements of the atoms.
n=empirical formula mass÷ molecular formula mass
n=1,2,3....
empirical formula mass = 373.69 g/mol
molecular formula mass= 186.85 g/mol
substituting all the given values in the above formula, we get
n= 186.85 g/mol÷ 373.69 g/mol
= 2
Multiply C[tex]_2[/tex]H[tex]_3[/tex]Br[tex]_2[/tex] by 2, which comes out to be C[tex]_4[/tex]H[tex]_6[/tex]Br[tex]_4[/tex].
Therefore, the molecular formula is C[tex]_4[/tex]H[tex]_6[/tex]Br[tex]_4[/tex]. The correct option is option E.
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Element X has an electron configuration of 2-8-2. This element will combine with the oxide ion to form a compound with the formula
A team of scientists is working to find the boiling point of a liquid at very low pressure. After three trials, the team has an average
of 12.3°C. An additional trial gives a result of 13.1°C. Which statement is a reasonable conclusion that can be drawn from this
result? (1 point)
O The original average should be thrown out because it could not be confirmed by new results.
O More data should be collected because the first three trials appear to be wrong.
O The original average should be used because it came from three results, not just one.
O More data should be collected to get a more reliable average.
Since it is conventional in science to use an average not just a single result, the original average should be used because it came from three results, not just one.
The boiling point refers to the temperature when the pressure of the fluid equals the atmospheric pressure. Hence, boiling occurs at atmospheric pressure.
In scientific experiments, it is common to conduct experiments more than once and obtain an average value for the measurement. In this case, the original average should be used because it came from three results, not just one.
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_________.__________ and___________ are energy science
Answer:
Chemical, Mechanical, and Nuclear Energy
Explanation:
PLEASE I WILL GIVE BRAINLISET PLS HELPPPP
Answer:
the answer is A because the rest wouldnt go good with the work
Explanation:
in a test trial, using 6% extra strength bleach at room temperature, 100.0 mL of oxygen gas was produced in 2.03 seconds. Calculate the average reaction rate for the oxygen gas.
The average reaction rate for oxygen gas is 49.26 mL/s
The average reaction rate of a substance refers to the speed at which a reaction occurs and therefore products are formed. In the reaction presented, oxygen gas is the product.
Moreover, the average reaction rate can be expressed in mL per second or mL/s, and the formula to calculate it is:
Product in mL/seconds
Let's calculate the reaction rate:
100 mL/ 2.03 s = 49.26 mL/sLearn more about oxygen in: https://brainly.com/question/1506082
LAST ATTEMPT! Covalent compound naming !
Answer:sad
Explanation:
haaaaan not
Consider Zn + 2HCl → ZnCl2 + H2 (g). If 0.30 mol Zn reacts with HCl, how many grams of HCl are needed?
Answer:
22 grams
Explanation:
Zn + 2HCl → ZnCl2 + H2
The first step to answering this question is to calculate the amount of moles of HCl needed. We do this by multiplying the coefficient of HCl in the equation over the coefficient of Zn.
0.30mol × [tex]\frac{2}{1}[/tex] = 0.60 mol HCl
Now, to figure out how many grams we must multiply the amount of moles of HCl by it's molar mass. This molar mass can be found by adding the molar masses of all the elements in HCl.
0.60mol × 36.46 g/mol = 21.87g
Using proper sig figs, 22 grams of HCl are required for this reaction.
why compounds with weak molecular forces are usually gases.
Molecular substances tend to be gases because the intermolecular forces of attraction are comparatively weak. You don't have to break any covalent bonds in order to melt or boil a molecular substance.
The longest intermolecular separation and hence the strongest intermolecular pressure of attraction can be found in the gaseous state of matter.
Although solids' intermolecular interactions were sufficient to maintain themselves in locked places, gases often have weak intermolecular forces that cause them to remain considerably separated. The gases possess greater intermolecular space than solids as a result of these weak forces.
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