Answer:
oxygen makes up 21 percent of the atmosphere
What is the name of this compound S2I4?
Answer:
Di Sulphur tetraiodide is the chemical compound with the formula S2I4
Explanation:
Which of the following is an example of a chemical change?
Answers
A. Boiling water
B. Burning paper
C. Dissolving sugar in water
D. Melting gold
Answer:
Dissolving sugar in water, burning paper, and melting gold are all chemical changes
Explanation:
The action cannot be reversed, or undone. Therefore it is a chemical change.
Boiling water is a physical change.
Something that causes a response in an organism is called a(n) _____.
How does the following equation demonstrate the law of conservation of mass? 22 + 2 → 22
A. The number of atoms of each element is the same on the reactant side as the product side.
B. The number of atoms on the reactant side is more than the number of atoms on the product side.
C. The number of water molecules is the same on the reactant and product side.
D. The number of atoms on the reactant side is less than the number of atoms on product side.
Answer:
A. The number of atoms of each element is the same on the reactant side as the product side.
Explanation:
The equation demonstrates the law of conservation of mass in such a way that the number of atoms of each element is the same on the reactant side as the product side.
According to the law of conservation of mass "matter is neither created nor destroyed in a chemical reaction but they are changed from one form to another".
By virtue of this, the number of moles of atoms on both sides of the expression must be the same.Suppose that 3.33 g of acetone at 25.0 °C condenses on the surface of a 44.0-g block of aluminum that is initially at 25 °C. If the heat released during condensation goes only toward heating the metal, what is the final temperature (in °C) of the metal block?
Answer:
68.6 °C
Explanation:
From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'
Q = Q'
Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g
Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown
So, mL = m'c(θ₂ - θ₁)
θ₂ - θ₁ = mL/m'c
θ₂ = mL/m'c + θ₁
substituting the values of the variables into the equation, we have
θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C
θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C
θ₂ = 43.56 °C + 25 °C
θ₂ = 68.56 °C
θ₂ ≅ 68.6 °C
So, the final temperature (in °C) of the metal block is 68.6 °C.
The final temperature of the metal block is 74.97°C
What is the specific heat?The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.
From the parameters given:
The mass of acetone = 3.33 gThe number of moles of acetone is:
[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]
= 0.0573 mol
At standard conditions, the heat of vaporization of acetone is:
[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]
Given that:
The mass of the metal (m) = 44.0 gThe initial temperature [tex]\mathbf{T_1}[/tex] = 25° CThe final temperature [tex]\mathbf{T_2 = ???}[/tex]The specific heat of the aluminum is = 0.903 J/g° C
The heat energy can be computed as:
q = msΔT
q = 41 g × 0.903 J/g° C × (x - 25°C)
Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.
i.e.
[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]
[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]
[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]
[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]
[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]
[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]
x = 74.97 °C
Learn more about specific heat here:
https://brainly.com/question/1430612
Please help outttt:(
Explanation:
1)
2Fe+3Cl2 →2FeCl3
2)
CH4+2O2 → CO2 +2H2O
3)
SnO2+2H2 →2H2O +Sn
4)
2KOH + H2SO4 → K2SO4+2H2O
How many liters of O2 at STP will react with 8.7 grams of C2H4 to form CO2 and H2O? C2H4 + 3 O2 -------> 2 CO2 + 2 H2O
Answer:
6.944 liters of O₂ at STP will react with 8.7 grams of C₂H₄ to form CO₂ and H₂O.
Explanation:
The balanced reaction is:
C₂H₄ + 3 O₂ ⇒ 2 CO₂ + 2 H₂O
Being the molar mass of the elements:
C: 12 g/moleH: 1 g/moleThen the molar mass of compound C₂H₄ is:
C₂H₄= 2*12 g/mole + 4*1 g/mole= 28 g/mole
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), 1 mole of C₂H₄ acts. Then, being the mass of a mole of a substance, which can be an element or a compound, 1 mole of C₂H₄ is 28 g, which is the amount of mass that reacts in this case.
Then be able to apply the following rule of three: if by stoichiometry 28 grams of C₂H₄ react with 3 moles of O₂, 8.7 grams of C₂H₄ with how many moles of O₂ do they react?
[tex]moles of O_{2} =\frac{8.7 grams ofC_{2} H_{4}*3 moles of O_{2} }{28grams ofC_{2} H_{4}}[/tex]
moles of O₂= 0.31
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then we can apply the following rule of three: if by definition of STP 1 mole occupies 22.4 L, 0.31 moles how much volume will it occupy?
[tex]volume=\frac{0.31 moles*22.4 L}{1 mole}[/tex]
volume= 6.944 L
6.944 liters of O₂ at STP will react with 8.7 grams of C₂H₄ to form CO₂ and H₂O.
The volume of O₂ at STP that will react with the given C₂H₄ is 20.8 L
First, we will determine the number of moles of O₂ required.
From the given balanced chemical equation,
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
This means
1 mole of C₂H₄ is required to react completely with 3 moles of O₂
Now, we will determine the number of moles of C₂H₄ present
Mass of C₂H₄ = 8.7 g
Using the formula
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass}[/tex]
Molar mass of C₂H₄ = 28.05 g/mol
∴ Number of moles of C₂H₄ = [tex]\frac{8.7}{28.05}[/tex]
Number of moles of C₂H₄ = 0.31016 mole
Since
1 mole of C₂H₄ is required to react completely with 3 moles of O₂
Then,
0.31016 mole of C₂H₄ will react completely with 3 × 0.31016 mole of O₂
3 × 0.31016 = 0.9305 mole
∴ Number of moles of O₂ required is 0.9305 mole
Now, for the volume of O₂ at STP that will react
Since 1 mole of a gas occupies 22.4 L at STP
Then,
0.9305 mole of O₂ will occupy 0.9305 × 22.4 L at STP
0.9305 × 22.4 = 20.8432 L
≅ 20.8 L
Hence, the volume of O₂ at STP that will react with the given C₂H₄ is 20.8 L
Learn more here: https://brainly.com/question/15209655
Chloe wants to lighten the color of her dark hair, which will require the use of both haircolor and hydrogen peroxide. Hydrogen peroxide (H2O2) is an example of a(n):
compound molecule.
elemental molecule.
immiscible liquid.
miscible liquid.
Answer:
H₂O₂
Explanation:
Hydrogen peroxide is a typical example of a compound molecule. A compound is made up of one or more atoms that are combined together in a definite grouping.
The properties of a compound is different from those of the elements that combines to from them.
A molecule is a covalent compound that has discrete or separate units. The formula of such compound represents a certain discrete entity. From this problem, we know that hydrogen peroxide is a covalent compound27 grams of Silver was reacted with excess sulfur, according to the following equation:
2Ag+S ---> Ag2S
25 grams of silver sulfide was collected, what is the the theoretical yield, actual yield, and percent yield? Please explain or show your work, it'll really help.
Answer:
percent yield = 80.7%
Theoretical yield of silver sulfide = 30.975 g
Actual yield = 25 g
Explanation:
Given data:
Mass of silver = 27 g
Mass of silver sulfide formed = 25 g
Theoretical yield of silver sulfide = ?
Actual yield = ?
Percent yield = ?
Solution:
Chemical equation:
2Ag + S → Ag₂S
Number of moles of Ag:
Number of moles = mass/molar mass
Molar mass of silver = 107.8 g/mol
Number of moles = 27 g/ 107.8 g/mol
Number of moles = 0.25 mol
Now we will compare the moles of silver with silver sulfide.
Ag : Ag₂S
2 : 1
0.25 : 1/2×0.25 = 0.125 mol
Theoretical yield of silver sulfide:
Mass = number of moles × molar mass
Mass = 0.125 mol × 247.8 g/mol
Mass = 30.975 g
Actual yield is given in question = 25 g
Percent yield:
Percent yield = (actual yield / theoretical yield) × 100
Percent yield = (25 g/ 30.975 g ) × 100
percent yield = 80.7%
Try to balance the 5 attached equations.
Answer:
1)2kclo3=2kcl+3o2
2)2NaCl+F2=2NaF+cl2
3)Pb(OH)2+2HCl=2H2O+PbCl2
4)2Albr3+3k2so4=6kbr+al2(so4)3
5)CH4+2O2=CO2+2H2O
Could someone help me with this thank you!
Answer:
The answer is D
I searched it up to verify.
Answer: I think the possible answer is B or D
Explanation: There are few of the energies like: Gravitational, electrical, Chemical.....
There are 2 grams of sulfur and 0.45 grams of copper. What is the
percent composition of coppper in the sample.
A. 18.3 %
B. 5.44 %
C. 81.6 %
D. 1.25%
Answer:
18.3%
Explanation:
Add the numbers together, and then take the number of grams of the substance, in this case copper, not coppper lol. divide the .45 by 2.45 to get 18.3
True or false A recent investigation found relatively high levels of the metalloid
arsenic in samples of apple juice. This would not be harmful
because arsenic is a stable metalloid.
Answer:
False
Explanation:
I took the quiz and got it right
When you increase the volume on your television, what is happening to the sound waves coming out of the speaker?
determine the molar mass of a sample of a compound that contains 6.0 mol and has a mass of 14.6 g
Explanation:
moles=mass÷molar mass
n=m÷Mr
6.0=14.6÷Mr
Mr=14.6÷6.0
Molar mass= 2.433
5. Explain why both diet and regular soft drinks can
damage the enamel on the surface of teeth.
Answer:
diet soda has artificial sugar and regular soda has insane amounts of sugar
How many moles are 21.67 L of NH4CI?
Answer:
0.967mole
Explanation:
Given parameters:
Volume of NH₄Cl = 21.67L
Unknown:
Number of moles = ?
Solution:
If we assume that the volume was taken at standard temperature and pressure,
Then;
Number of moles = [tex]\frac{volume }{22.4L}[/tex]
Number of moles = [tex]\frac{21.67}{22.4}[/tex] = 0.967mole
what elements comprise the largest portion of Earth's atmosphere?
Answer:
Nitrogen and Oxygen make up 99% of the Earths atmosphere. Then Argon makes up the rest of the atmosphere.
Which element is most similar to fluorine in the way it reacts with other elements?
Answer:
The answer is chlorine
Explanation:
All changes saved
A gas is at 275 K, and its temperature is raised to 400 K. The volume is measured at 5.82 L after the gas is heated. What is
the volume of the gas before it is heated?
8.25 L
12.0L
2.00 L
4.00 L
Answer:
4.00L
Explanation:
Using Charle's law, which have the following equation:
V1/T1 = V2/T2
Where;
V1 = initial volume (litres)
T1 = initial temperature (Kelvin)
V2 = final volume (litres)
T2 = final temperature (Kelvin)
According to the information provided, T1 = 275K, T2 = 400K, V1 = ?, V2 = 5.82L
Hence, using the formula;
V1/275 = 5.82/400
400 × V1 = 275 × 5.82
400V1 = 1600.5
V1 = 1600.5 ÷ 400
V1 = 4.001
Therefore, volume of the gas before it is heated is 4.00L
which type of clouds are shown?
cirrocumulus
cumulonimbus
cumulus
stratus
Explanation: cirrocumulus
Please help me with this question
Thank you!
Answer:
B. 3+
Explanation:
When Fe²⁺ loses an electron, it becomes an Fe³⁺ ion.
The loss of an electron in an atom makes the atom becomes positively charged. Further losing electrons makes the atom more positive.
For the given ion;
Fe²⁺ if it loses an electron more, it becomes Fe³⁺.
The expression is given as:
Fe²⁺ → Fe³⁺ + e⁻
16. DNA in a eukaryotic cell is contained in
A) a nucleus
B) a protein molecule
C) an enzyme molecule
D) a chromosome
Answer:
A. Nucleus
Nucleus is the answe
FOR LondonCreamCakes
no sure if its right but im trying to help.. lol dont mind all the tabs
Answer:
It kinda helps but not really
Thanks for trying anyway doe!
Explanation:
how do you classify the society on the basis of economy write one characteristic of any two of them
Answer:
Explanation:
(1) The primary industry is mainly agriculture, which includes agricultural, forestry, animal husbandry and fishery components. Agriculture is the foundation of social economy. (2) The secondary industry, which mainly includes the industrial and construction industries.
how did leeuwenhoek discover bacteria
Answer:
Antonie van Leeuwenhoek used single-lens microscopes, which he made, to make the first observations of bacteria and protozoa. His extensive research on the growth of small animals such as fleas, mussels, and eels helped disprove the theory of spontaneous generation of life.
Explanation:
Hope this helps and have a great day :)
how many element are there on the periodic table?
Answer:118
Explanation: it’s right
Answer:
118 elements
Hope that helps
How many moles are there in 2.43e+21 molecules of carbon dioxide?
Moles of Carbon dioxide : n = 4.037 x 10⁻³
Further explanationGiven
2.43 x 10²¹ molecules of Carbon dioxide
Required
Moles
Solution
1 mol = 6.02 x `10²³ particles(molcules, atoms, ions)
Can be formulated :
N = n x No
n = moles
No = Avogadro's number 6.02 x `10²³
moles of Carbondioxide :
n = N/No
n = 2.43 x 10²¹ / 6.02 x `10²³
n = 4.037 x 10⁻³
Which of the following molecules has a tetrahedral shape?
A. SiH4
B. PCI3
C. BCI3
D. H20
Answer:
SiH4
Explanation:
4 hydrogens serve a the base and the Si is on top which forms a tetrahedral shape.
Ethanol is used for drinking purpose. why?
Answer:
Ethanol has a higher octane number than gasoline, providing premium blending properties, according to the U.S.
Explanation:
Department of Energy. Minimum octane number requirements prevent engine knocking and maintain drivability.