Answer:
The two most abundant compounds in air are the gases carbon dioxide, CO2, and water vapor, H2O
Answer:
Nitrogen
Explanation:
Nitrogen is the most abundant compound found in the air. It accounts for about 78% of the air that we breath. It is closely followed by oxygen that accounts for about 21% of the air.
Which substance is the least toxic?
a. chlorine (LD50 = 850 mg/kg)
b. vitamin A (LD50 = 2000 mg/kg)
c. cola (LD50 = 140 mg/kg)
d. aspirin (LD50 = 200 mg/kg)
Answer:
I believe it's D. I searched up a lethal table chart and it states Aspirin is even more toxic than chlorine. As for the other two, it didn't specifically state it was toxic with one dose - meaning you have to take more than one dose for toxicity to take effect.
Explanation:
What is the molecular mass for a non-electrolyte if 35.0 g of it is dissolved in 45.0 grams of water and the solutions boiling point is 101.25oC? (The KB for H2O is .51°C/m)
The boiling point of water increases as the amount of impurities dissolved in it increases. For our purposes, we will consider the non-electrolyte to be the dissolved impurity. The change in the boiling point can be calculated using the equation:
[tex]\Delta T_b = i \times K_b \times m[/tex]
where [tex]\Delta T_b[/tex] is the change in boiling point, [tex]i[/tex] is the van ‘t Hoff factor (whose value denotes the number of particles each formula unit of the dissolved substance dissociates into in water), [tex]K_b[/tex] is the boiling point elevation constant, and [tex]m[/tex] is the molality (moles of solute/kilogram of solvent) of the solution.
Right off the bat, since we're dealing with a non-electrolyte, the dissolved substance can be assumed not to dissociate in water. So, our van ‘t Hoff factor, [tex]i[/tex], would be 1 (by contrast, the [tex]i[/tex] for an ionic compound like NaCl would be 2 since, in water, NaCl would dissociate into two particles: one Na⁺ ion and one Cl⁻ ion). We're also given our [tex]K_b[/tex], which is 0.51 °C/m.
Assuming the normal boiling point of pure water to be 100 °C (a defined value for sig fig purposes), the change in boiling point from having dissolved 35.0 g of the non-electrolyte can be obtained by subtracting 100 °C from the final—elevated—boiling point of 101.25 °C:
[tex]\Delta T_b = 101.25\text{ }^o\text{C} - 100\text{ }^o\text{C} = 1.25\text{ }^o\text{C}[/tex]
Now, recall what we're asked to determine: the molecular mass of the dissolved substance. There is one unknown left in the equation: the molality of the solution. Let's first solve for that:
[tex]m = \frac{\Delta T_b}{K_b} = \frac{1.25^\text{ o}\text{C}}{0.51^\text{ o}\text{C}/m} \\ m = 2.45 \text{ mol solute/kg water}.[/tex]
Notice that we didn't include the i since its value is 1.
Now, what would happen if we multiplied our molality by the mass of water we've been given? We would be left with the moles of solute. And what are we asked to find? The molecular mass, or the mass per mole. We can accomplish this in two steps. Remember to convert your mass of water to kilograms:
[tex]2.45 \text{ mol solute/kg water} \times 0.045 \text{ kg water} = 0.110 \text{ mol solute.}[/tex]
And, finally, we divide the mass of our solute by the number of moles of solute:
[tex]\frac{35.0 \text{ g solute}}{0.110 \text{ mol solute}} = 317.5 \text{ g/mol}[/tex]
Our answer to two significant figures (which is the number of sig figs to which our [tex]K_b[/tex] is given) would be 320 g/mol.
Is the following chemical equation balanced?
C₁₀H₂₂ + 31 O₂ ⟶ 20 CO₂ + 22 H₂O
Answer:
Yes- i balanced it-
Explanation:
Can someone please help me with this, ill give you a heart, a five star rating, and the brainliest answer!
Answer:
A not
B yes
C yes
D yes
Explanation:
A 2C 6H but 10O and 7O so no
B 3C 6O 2Fe on each side so yes
C 4H 1S 6O 2Na so yes
D 2Ag 2Cl 1Ca 2N 6O so yes
6. Un átomo de sodio tiene 11 protones, 12 neutrones y 11 electrones, a) ¿cuál es la masa en gramos de este átomo de sodio? b) Si este átomo de sodio pierde un electrón para quedar cargado positivamente (Na+1) ¿Cuál es su nueva masa? ¿cuánto cambió en porcentaje con respecto a la masa original (la del literal a))? c) Si todos los átomos de sodio fueran iguales ¿cuántos átomos de sodio hay en un miligramo?
Answer:
a. 3.851301x10⁻²³g
b. La masa del Na⁺ es 3.85121x10⁻²³g y 0.002% es el cambio percentual.
c. 2.6x10¹⁹ átomos hay presentes.
Explanation:
a. La masa de un electrón es 9.1x10⁻²⁸g
La de un protón es 1.673x10⁻²⁴g
La de un neutrón es 1.675x10⁻²⁴g
La masa del átomo de sodio es:
11*1.673x10⁻²⁴g + 12*1.675x10⁻²⁴g + 11*9.1x10⁻²⁸g =
3.851301x10⁻²³gb) Ahora, con 10 electrones la masa es:
11*1.673x10⁻²⁴g + 12*1.675x10⁻²⁴g + 10*9.1x10⁻²⁸g =
3.85121x10⁻²³gEl cambio percentual es:
3.851301x10⁻²³g - 3.85121x10⁻²³ / 3.851301x10⁻²³ * 100 =
0.002% es el cambio percentual.c. 1 átomo de sodio pesa 3.851301x10⁻²³g, 1mg = 1x10⁻³g tendrán:
1x10⁻³g * (1 átomo / 3.851301x10⁻²³g) =
2.6x10¹⁹ átomos hay presentesWhat does the skeleton do
Explanation:
"The skeletal system works as a support structure for your body. It gives the body its shape, allows movement, makes blood cells, provides protection for organs and stores minerals"
PLS HELP!!! i have no idea what this could be
Answer:
121.5g
Explanation:
from the equation:
2mol of Al react to give 3 mol of Zn
i.e 81g of Al will give 3×81/2 = 243/2 = 121.5g
PLEASE HELP ITS PAST DUE IM GIVING BRAINLIEST
Answer:
it will option A . hope it helps
Answer:
options A
Explanation:
the balloon filled up because of the formation of gas bubbles
If I combine atoms then I must be performing which process?
A) Radiation Reaction
B) Strong Force
C) fission
D)Fusion
Answer:
D: fussion
Explanation:
The process called nuclear fussion.
for example, four hydrogen atoms combine in a nuclear fussion reaction to form one helium atom.
You are watching the Indy 500 car race on television with your brother. He says, "Did you know that these cars race at a speed of over 200 mph? That velocity is amazing!" Having learned that speed and velocity are not the same, you decide to explain the difference to your brother.
Answer:
See explanation
Explanation:
All physical quantities are broadly classified into scalar quantities and vector quantities.
Scalar quantities have magnitude but do not have direction. Vector quantities have both magnitude and direction. Hence the main difference between a scalar quantity and a vector quantity is that a vector has direction while a scalar quantity does not.
Speed is a scalar quantity while velocity is a vector quantity. You have just specified a magnitude of 200 mph without mentioning its direction. This implies that you are referring to speed of the cars in the race and not velocity because velocity of the cars must indicate the direction!
Can someone help me please
Urgent please help!!!
Describe what you think is your responsibility in taking care of the natural
world in which you live.
Answer:
Well I would say " I think my responsibility is recycling, gardening, picking up litter, and using less pollution. All of this stuff is very important. Sometimes, it's the tiny things that change the world for the better."
I hope this helped! Feel free to add your own little tweaks.
Which one of the following is an incorrect orbital notation?
B. 4f
C. 2d
D. 3s
E. 2p
(no 'A')
The answer option which is an incorrect orbital notation is: C. 2d.
A sublevel refers to an energy level that is typically associated with the valence electrons found outside an atomic nucleus.
In Chemistry, there are four (4) main types of sublevel and these includes:
s orbital (sublevel): 3sp orbital (sublevel): 2pd orbital (sublevel): 3df orbital (sublevel): 4fHowever, it is impossible for any atom of a chemical element to have a 2d orbital because electrons are generally located in the s and p orbitals (sublevels) in the second energy level.
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the usa flag..........
Answer:
lol
Explanation:
how many mililiters is 0.55 L
Answer:
It's 550 milliliters.
Explanation:
I hope this helps.
How many electrons can each individual orbital hold?
Answer:
Orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin state. Noble-gas configuration refers to an outer main energy level occupied, in most cases, by eight electrons.
Explanation:
I hope this helps you.
Answer:
Two electrons
Explanation:
Each individual orbital can hold a maximum of two electrons. Hope this helps :)
Help pleaseedeeeeeeeeeeeeeeee
Answer:
the answer to this question here is A
Explanation:
trust me
Answer:
Acid and Salt
Explanation:
Common hydrogen compounds
Hydrogen combines with other elements, forming a number of compounds, including common ones such as water (H2O), ammonia (NH3), methane (CH4), table sugar (C12H22O11), hydrogen peroxide (H2O2) and hydrochloric acid (HCl), according to Jefferson Lab.
A student mixes strawberry koolaid and water. A pH meter is used to measure pH of 5.4. What kind of solution is strawberry Koolaid?
Answer:
Slightly Acidic
Explanation:
Slightly acidic ph is 5.0-5.5
What are two functions of dermal tissue in plants?
A.Control the entry and exit of water
B.Cover the outside of plants
C.Contain cells that connect to form pipes
D.Transport water and food
Answer:
A and B
Explanation: Dermal tissue functions to protect the plant from injury and water loss.
Na + O2 → Na2O2
Can you guys help me !
Answer:
Explanation:
Assuming that you are asking for the full-balanced equations...
2Na + O2 = Na2O2
H2 + O2 = H2O2; This equation is already balanced, there is no need for change.
Please let me know if this is not the answer you are looking for and I will amend the answer.
Differentiate between molecule and mole.
Answer:
Explanation:
A molecule, for example of water, contains 2 hydrogen atoms and 1 oxygen atom chemically bonded together and is the smallest building block of the chemical water. ... A mole is a certain quantity of molecules, specifically 6.02 x 10^23.
Hope this helps!
What role does the vulture playing this food web
Answer:
scavenger- eats dead carcasses
Explanation:
How many carbon atoms are in 27.0g of carbon (C)?
in which of the following does the land being moved contin approximately 60% water
Answer:
C
Explanation:
The answer is C because only that amount can move
atoms, predict the ratio of metal cationic (+) atom
to nonmetal anionic (-) atom in the compound.
Lithium 1s22s1
Chlorine 1s22s22p6 3s23p5
A. 1:1
B. 1:2
C. 2:1
D. 3:1
D. 3:1
Answer:
A. 1:1
Explanation:
Lithium 1s2 2s1
Chlorine 1s2 2s2 2p6 3s2 3p5
Lithium is a group 1 element. When it forms a compound, it loses it's one valence (outermost) electron.
Chlorine is a group 7 element. When it forms a compound, it gains one electron to achieve a stable electronic configuration.
Since Li loses one electron and Cl gains one electron. The formular of the compound formed would be;
LiCl
The correct option is;
A. 1:1
2H20 → 2H2 + O2
Type of reaction?
Answer:
Notice how the elements splitIt is a decomposition reaction I do exams and quizzes if ur interestedFurnaces are typically located in basements. Which room would most likely feel the effects of the furnace first kicking
on?
the basement
a room on the first floor
a room on the second floor
the garage
Answer:
the answer is A ( The basement)
HOPE THAT HELPSSS!!!
Answer the basement
Explanation: i took the test
Why do molecular compounds have low melting points and low boiling points relative to ionic substances?
Answer:
The melting and boiling points of molecular compounds are generally quite low compared to those of ionic compounds. This is because the energy required to disrupt the intermolecular forces between molecules is far less than the energy required to break the ionic bonds in a crystalline ionic compound
You spill some acid on your clothes, causing a large hole to form where the acid touched the cloth. chemical or physical change.
Answer: Chemical
Explanation:
Answer:
Ah I think it's Chemical
Explanation:
Maybe, because it wasn't just move onto something, it changed it.
is mending a broken bone chemical change and why(short answer pls)
Answer:
In a physical change, the substances involved retain their original properties. A new substance is not formed. A physical change can be reversed. Chemical changes happen on a molecular level when two or more substances chemically bond together.
Mending a broken bone is a chemical change as to heal the bone enzymes are released which are chemicals.
What is a chemical change?Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
Learn more about chemical change,here:
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