Why do need need pure substances
Answer:
To extract its derivatives without impurities
What is the empirical formula of a compound containing 5.03 g carbon, 0.42 g hydrogen, and 44.5 g of chlorine
Answer:
CHCl₃
Explanation:
We have the following data:
C = 5.03 g
H = 0.42 g
Cl= 44.5 g
First, we divide each mass by the molar mass (MM) of the chemical element to calculate the moles:
MM(C) = 12 g/mol
moles of C = mass/MM(C) = 5.03 g/(12 g/mol) = 0.42 mol C
MM(H) = 1 g/mol
moles of H = mass/MM(H) = 0.42 g/(1 g/mol) = 0.42 mol H
MM(Cl) = 35.4 g/mol
moles of Cl = mass/MM(Cl) = 44.5 g/(35.4 g/mol) = 1.26 mol Cl
Now, we divide the moles by the smallest number of moles (0.42):
0.42 mol C/0.42 = 1 C
0.42 mol H/0.42 = 1 H
1.26 mol Cl/0.42 = 3 Cl
Thus, the C:H:Cl ratio is 1:1:3.
Therefore, the empirical formula is CHCl₃
Answer:
CHCl₃
Explanation:
Which substance is a binary acid?
hydrochloric acid
phosphoric acid
nitrous acid
sulfuric acid
Answer:
A) Hyrdrochloric Acid
Explanation:
This is because binary acids are molecular compounds in which hydrogen is combined with a non-metal element. Hydrochloric acid has hydrogen present in it's compound, therefore identifying it as the only binary acid amongst the answer choices.
what are the characteristics or properties that you can use to classify elements
Answer:
The number of outermost energy level electrons ( valency electrons )
The atomic number
what is an earthquake's epicenter found
Answer:
an epicenter is where an earthquake first hit
Answer:
The epicenter
Explanation:
The location below the earth's surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. ... These are smaller earthquakes that occur afterwards in the same place as the mainshock.
What happens to the freezing point of a solution when more solute is added?
Answer:
Explanation:
Freezing point depression is the phenomena that describes why adding a solute to a solvent results in the lowering of the freezing point of the solvent. Adding solute to a solvent will essentially dilute the solvent molecules
Answer:
The freezing point decreases
Calculate the standard enthalpy change for the reaction 2A+B⇌2C+2D Use the following data: Substance ΔH∘f (kJ/mol) A -235 B -413 C 193 D -493
Answer:
ΔH = 283kJ/mol
Explanation:
Using Hess's law, the ΔH of a reaction is equal to the sum of ΔH° of products times its coefficient subtracting the sum of ΔH° of reactants times its coefficient. Replacing, for the reaction:
ΔH = 2ΔH°C + 2ΔH°D - (2ΔH°A+ΔH°B)
ΔH = 2*193kJ/mol + 2*-493kJ/mol - (2*-235kJ/mol+ (-413kJ/mol)
ΔH = 283kJ/molThe electronegativities of carbon and sulfur are almost the same. Both elements form covalently bonded compounds with hydrogen. Why is hydrogen sulfide a polar compound while methane is a nonpolar compound?
a.Sulfur has a stronger attraction for electrons than does carbon
b.A hydrogen sulfide molecule has lone pairs of electrons
c.Sulfur forms ionic bonds with hydrogen while carbon forms covalent bonds
d.Sulfur ions are larger than carbon ions
Answer:
b. A hydrogen sulfide molecule has lone pairs of electrons
Explanation:
The presence of lone pairs indictates that the molecule will be polar unless its molecular geometry is linear or square planar. In the case of H2S, its shape is bent due to the lone pair and it is a slightly polar molecule.
Which property of metals makes them good conductors of electricity?
A. Their melting point
B. Their mobile electrons
C. Their hardness
D. Their ductility
Answer:
their mobile electrons
Help!! Please explain how you get the answer
Answer:
5 moles
Explanation:
First, write out the balanced equation:
2Al + Fe₂O₃ → Al₂O₃ + 2Fe
Reaction ratio of Al to Fe₂O₃ is:
2 : 1
This means 2 moles of Al will react with 1 mole of Fe₂O₃
Al: 5 mol
Fe₂O₃: 3 mol
Multiply the reaction to get moles of both reactants you have:
2 : 1 (×⁵/₂) = 5 : ⁵/₂
2 : 1 (×3) = 6 : 3
In other words, 5 moles of Al will react with ⁵/₂ moles of Fe₂O₃;
And 3 moles of Fe₂O₃ will react with 6 moles of Al;
But, we do not have 6 moles of Al, therefore only the 5 moles of Al available will react;
5 moles of Al reacts with ⁵/₂ moles of Fe₂O₃, as we can see from the ratios we calculated above, the remaining ¹/₂ mole of Fe₂O₃ will not react;
We say that Al is the limiting reactant because all the Al will react but all the Fe₂O₃ does not (i.e. it is in excess);
Next and last, the reaction ratio of Al to Fe is:
2 : 2 or, more simply 1 : 1
This means the moles of Al that reacts is the equal to the moles of Fe produced from the reaction;
We've established that 5 moles of Al will react with ⁵/₂ moles of Fe₂O₃, so 5 moles of Fe will also be produced (since the ratio is 1 : 1);
You could also work this out using the moles of Fe₂O₃ that react;
The reaction ratio of Fe₂O₃ to Fe:
1 : 2
So the moles of Fe produced is 2× the moles of Fe₂O₃;
If ⁵/₂ moles of Fe₂O₃ reacts, then simply multiply this by 2 which is 5 moles
Which statement about the mass of an electron is correct? A The mass of an electron is equal to the mass of the proton. B The mass of an electron is less than the mass of the proton. с The mass of an electron is equal to the mass of a neutron. D The mass of an electron is greater than the mass of a neutron.
Answer:
B
Explanation:
because mass of an electron is 1/2000.
The statement about the mass of an electron which is correct is: B. The mass of an electron is less than the mass of the proton.
An atom refers to a smallest, indivisible unit that comprises the matter that forms all chemical elements. Therefore, atoms are typically considered as the fundamental building blocks of matter which determines the structure of a chemical element.
Basically, an atom consists of three (3) distinct particles and these include;
Protons. Neutrons. Electrons.
Electrons are the subatomic particles of a chemical element that are negatively charged with a magnitude of -1.
On the other hand, protons can be defined as the subatomic particles of a chemical element that are positively charged.
All of these subatomic particles of a chemical element has a mass. However, the mass of an electron is significantly less than the mass of proton, as a result of its extremely small size.
In conclusion, the mass of an electron is approximately 2000 times smaller than that of a proton and as such contributes almost nothing to the total mass of an atom.
Find more information: https://brainly.com/question/18214726
An apple has been left out, and it is starting to rot. Which of the following is the best method to slow down the chemical changes that are occurring?
The best method is to keep rinsing the apple with water every hour.
The best method is to keep the apple in a cooler place.
The best method is to put the apple in the sun to warm it up.
The best method is to wrap the apple in plastic.
Chloe’s teacher gives her and her lab partner soil samples from different parts of the city: the park, the area next to a pond, the school, and a neighborhood. Chloe’s teacher also gives her a soil tester kit, which determines the pH of the soil. Chloe and her lab partner need to determine the pH of each soil sample and then compare them.
Fill in the blank with the word that best completes the statement.
This investigation is a(an)______investigation.
Answer:
an
Explanation:
It is AN because investigation starts with I ( i is a vowel). When there are vowels we use An.
Pls mark me brainliest!
A magnesium ion, Mg2+, is formed from a magnesium atom, Mg.
Which row about the numbers of protons and neutrons in the magnesium ion and in the magnesium atom is correct?
Why the answer for this question is B.
Pls help to explain it. Thank you.
Answer:
The correct row is B.
Explanation:
The formation of the magnesium ion, Mg²⁺, comes from the removal of 2 electrons from the valence shell of the magnesium atom. Since the remotion is of electrons, the nucleus of the atom remains the same, so the number of protons and the number of neutrons does not change.
If the number of proton change, then the atom also change, since the identity of an atom is related to the atomic number which is the same to the proton number.
Now, if the number of neutrons changes, then we would be in the presence of an isotope of the magnesium atom.
Therefore, the correct row is B.
I hope it helps you!
Which of the following pairs of elements is most likely to form an ionic compound?
• magnesium and sodium
• nitrogen and sulfur
• oxygen and chlorine
• magnesium and chlorine
• carbon and fluorine
Explanation:
magnesium and sodium because they are minerals and part of iron
what's the chemical formula for salt, like is it NaCl??
the salt we eat???????
yeah it's NaCl, I just looked it up
Answer:
Yes
Explanation:
NaCl is table salt
Also known as sodium chloride
HELP ASAP
Which of these 3 metals ,reacts more vigorously? Sodium, potassium or lithium *
a)Sodium reacts the most vigorously.
b)Potassium reacts the most vigorously.
c)Lithium reacts the most vigorously.
potassium reacts the most vigorously.
will give u brainliest plzz help
Answer:
4.76 mol / L
Explanation:
The process that takes place is:
Sc₂(C₂O₄)₃ → 2Sc⁺³ + 3C₂O₄⁻²Assuming we have 1 L of the solution, we would have 2.38 moles of Sc₂(C₂O₄)₃.
We then convert 2.38 moles of Sc₂(C₂O₄)₃ into moles of Sc⁺³, using the stoichiometric coefficients:
2.38 mol Sc₂(C₂O₄)₃ * [tex]\frac{2molSc^{+3}}{1molSc_2(C_2O_4)_3}[/tex] = 4.76 mol Sc⁺³Finally we calculate the concentration of scandium ion (Sc⁺³) in mol/L:
4.76 mol Sc⁺³ / 1 L = 4.76 mol/LDescribe the formation of calcium chloride (4 marks)
Answer:
It is an ionic compound that consists of one calcium cation Ca2+ and two chlorine anions. The bivalent calcium metal forms an ionic bond with two chlorine atoms. The formation of cacl2 happens mainly by reacting limestone (CaCo3) with hydrochloric acid (HCl).
WHAT IS THE STOCK NAME FOR FeSO^3
Why don’t scientists use the Bohr model above to explain charge transfer?
Answer:
nsksbsjensnsjeiejensbsksks
Which substance is an electrolyte?
A)
C2H5OH(C)
B)
NaOH(s)
C)
H2(g)
D)
C6H1206 (s)
Answer:
B)NaOH(s)
Explanation:
The table below gives some characteristics of element Y.
Characteristics of element Y Values
Mass number 11
Number of neutrons in a single atom 6
Average atomic mass (grams/mole) 10.81
What is the identity of element Y?
Answer:
Boron B
Explanation:
According to the periodic table, Boron is the element with atomic mass of approximately 11 [i.e 10.81]
To calculate Neutrons
Neutrons = Mass number - Protons
Number of protons in Boron is same as atomic number which is 5
Thus, N = 11 - 5 = 6
Which of the following statements regarding carbon is false? Group of answer choices Carbon has the capacity to form single and double bonds. Carbon has the ability to bond with up to six other atoms. Carbon has a tendency to form covalent bonds. Carbon has the ability to bond together to form extensive branched or unbranched "carbon skeletons."
Answer: The statement, carbon has the ability to bond with up to six other atoms is false.
Explanation:
Carbon is a group 14 element and it is a non-metal. The atomic number of carbon is 6 and its electronic distribution is 2, 4.
This means that there are 4 valence electrons present in it. Also, in order to attain stability a carbon atom forms only covalent bonds, that is, it shares its valence electrons with its own atoms or atoms of other elements.
Carbon has the capacity to form single and double bonds.
As valency of carbon is four so it can only combine to 4 other atoms vis single bond and it cannot bond with up to six other atoms.
Carbon shows the property of catenation, that is, it forms covalent bonds with its own atoms in a large number. So, carbon has the ability to bond together to form extensive branched or unbranched "carbon skeletons".
Thus, we can conclude that the statement, carbon has the ability to bond with up to six other atoms is false.
How do countries with different currencies trade goods with each other?
A.
They trade actual physical products to avoid confusion over currency differences.
B.
They negotiate to determine which country's currency will be used for the whole exchange.
C.
They create a new shared currency, such as the European Union countries' euro.
D.
They use the exchange rate to convert one country's currency to another's.
Answer:
D- They use the exchange rate to convert one's Country's currency to another's
Explanation:
A doctor is testing a new medication and he doesn’t tell the people in the study about the possible side effects of the medicine. He is _____.
why do objects cool down
Answer:
wla dyan ang sagut ehh baka mali yan
How many centimeters are in 5 miles? Hint: 1 miles = 5280 feet
Hydrogen and nitrogen react to form ammonia. The chemical equation for this reaction is shown here. 3 H2(g) + N2(g) 2 NH3(g). What amount of hydrogen will produce 44.0 mol of ammonia?
66.0 mol
88.0 mol
132.0 mol
29.3 mol
Answer:
someone already answered but i think it's 132.0 mol too
Lime is added to a lake to neutralize the effects of acid rain. The pH value of the
lake water rises from 4 to 7. What is the change in concentration of H+ ions in the
lake water?
Answer:
The change in concentration of H+ ions is -9.99×10⁻⁵
Explanation:
When pH rises, we talk about neutralization and, there is a decline in proton's concentration.
pH lower than 7 is acid
pH higher than 7 is basic
Protons are neutralized by hydroxides to make water as this:
H₃O⁺ + OH⁻ ⇄ H₂O
pH = - log [H₃O⁺]
[H₃O⁺] = 10^-pH
In conclussion: [H₃O⁺]₁ = 10⁻⁴ → 1×10⁻⁴
[H₃O⁺]₂ = 10⁻⁷ → 1×10⁻⁷
1×10⁻⁷- 1×10⁻⁴
The change in concentration of H+ ions is -9.99×10⁻⁵
