Answer:
D (32.7%)
Explanation:
Answer:D (32.7%)
Explanation:
I need help with this, I'm not understanding.
Answer:
C. 5 grams
Explanation:
The ratio is 2:1, which means everything on the right (B) will be half of the left (A). Since 10 is on the left, and half of 10 is 5, C is the answer
What is the volume, in liters, of 1.40 mol of oxygen gas at 20.0°C and 0.974 atm?
Answer:
V = 34.55 L
Explanation:
Given that,
No of moles, n = 1.4
Temperature, T = 20°C = 20 + 273 = 293 K
Pressure, P = 0.974 atm
We need to find the volume of the gas. It can be calculated using Ideal gas equation which is :
PV=nRT
R is gas constant, [tex]R=0.08206\ L-atm/mol-K[/tex]
Finding for V,
[tex]V=\dfrac{nRT}{P}\\\\V=\dfrac{1.4\times 0.08206\times 293}{0.974 }\\\\V=34.55\ L[/tex]
So, the volume of the gas is 34.55 L.
Calculate the density of an object with mass = 30.50 g and a volume = 2.20 cm^3
Answer:
The answer is 13.86 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 30.5 g
volume = 2.2 cm³
We have
[tex]density = \frac{30.5}{2.2} \\ = 13.863...[/tex]
We have the final answer as
13.86 g/cm³Hope this helps you
PLZ ANSWER WILL GIVE BRAINLIEST ASAP
Given the data below, what substance does not show a reaction for any of the tests? Hint: (+)= reaction occurred, (-)= no reaction
unknown
salt
Corn starch
Gelatin
Answer:
Salt
Explanation:
It has all -
How many total atoms of element X are represented below?
A scientist wants to prove that certain chemicals in cosmetics are likely to cause harm to developing fetuses, when used by a pregnant woman. What is the most likely limitation she will face in her scientific design? PLEASE HURRY!!
Answer:
D. Limitations due to ethical concerns about experimental subjects.
Explanation:
Answer:
A
Explanation:
(its my friend)
Write a balanced equation for the complete oxidation reaction that occurs when ethane burns in air
Alkanes are saturated hydrocarbons that have single bonds in chains
General formula for alkanes :
[tex]\tt \large{\bold{C_nH_{2n+2}}[/tex]
Hydrocarbon combustion reactions (specifically alkanes)
[tex]\large {\box {\bold{C_nH _ (_2_n _ + _ 2_) + \dfrac {3n + 1} {2} O_2 \Rightarrow nCO_2 + (n + 1) H_2O}}}[/tex]
So that the burning of ethane with air (oxygen):
[tex]\tt C_2H_6+\dfrac{7}{2}O_2\rightarrow 2CO_2+3H_2O[/tex]
2C₂H₆ (g) + 7O₂ (g) ⟶ 4CO₂ (g) + 6H₂O (ℓ)
or we can use mathematical equations to solve equilibrium chemical equations by giving the coefficients for each compound involved in the reaction
C₂H₆ (g) + aO₂ (g) ⟶ bCO₂ (g) + cH₂O (ℓ)
C : left 2, right b ⇒ b=2
H: left 6, right 2c⇒ 2c=6⇒ c= 3
O : left 2a, right 2b+c⇒ 2a=2b+c⇒2a=2.2+3⇒2a=7⇒a=7/2
Can you explain what vsepr stand for in your own word?
A metal block, 2.0cm x 2.5cm x 3.0cm, has a mass of 40.5g. What is the density of the sample? What type of metal is the metal block composed of?
Aluminum - 2.699
Copper - 8.92
Iron - 7.874
Lead - 11.43
Nickel - 8.908
Tin - 7.265
Zinc - 7.14
Answer:
The block is made up of aluminum.
density = 2.7 g/cm³
Explanation:
Given data:
Dimension of metal block = 2.0 cm×2.5 cm× 3.0 cm
Mass of block = 40.05 g
Density of block = ?
Which metal is this = ?
Solution:
Density:
Density is equal to the mass of substance divided by its volume.
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Volume of block = 2.0 cm×2.5 cm× 3.0 cm = 15 cm³
d = m/v
d = 40.5 g/ 15 cm³
d = 2.7 g/cm³
The block is made up of aluminum.
A 475 cm3 sample of gas at standard temperature (273 K) and pressure
(1 atm) is allowed to expand until it occupies a volume of 600. cm3. What
temperature would be needed to return the gas to standard pressure (1 atm)?
(n = constant
Answer:
T₂ = 344.8 K
Explanation:
Given data:
Initial volume of gas = 475 cm³
Initial temperature = 273 K
Final volume = 600 cm³
Final temperature = ?
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₂ = T₁V₂/V₁
T₂ = 273 K × 600 cm³ / 475 cm³
T₂ = 163800K . cm³ / 475 cm³
T₂ = 344.8 K
Does changing the number of protons change the identity of the element you have built ?
Answer: Yes.
Explanation:
the number of protons in the nucleus determines an element's identity. Chemical changes do not affect the nucleus, so chemical changes cannot change one type of atom into another. The number of protons in a nucleus does change sometimes, however. The identity of the atom, therefore, changes.
which of these elements is most likely to be magnesium the most metallic of all samples?
Answer:
B
Explanation:
Just did it on usa test prep
The element which is most likely to be magnesium is the element with the electronic configuration same as magnesium.
What is an element?It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
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QUICK I’ll GIVE BRAINLIEST
The number of isomers of C5H12 is:
Select one:
a. 4
b. 2
c. 5
d. 3
Answer:
The answer is option D 3
Explanation:
please mark as brainliest
Answer:
d.3
Explanation:
Calculate the answer. Express It In scientific notation. All answers should have the correct number of significant figures.
(4.9 x 10^-2) (9.80 x 10^2) =
48.02
48
48 x 10^-1
4.8 x 10^1
Answer:
4.8 x 10^1
Explanation:
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10. If the decimal is being moved t the right, exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
After stirring salt in a container of water, the salt will dissolve. When adding more salt, eventually the salt will not dissolve. Which of the following refers to a substance that can no longer dissolve in a liquid? *
A. boiling point
B. melting point
C. saturation point
D. all of these
Answer: C. Saturation point
Explanation:
Which of the following elements form +1 ions?
A sodium, magnesium, aluminum
B strontium, magnesium, calcium
C lithium, sodium, potassium
Answer:
It is 'A' i.e., Sodium magnesium, aluminium
Elements tend to lose and gain electrons to achieve electronic stability. Lithium, sodium, and potassium are the elements that form +1 ions. Thus, option C is correct.
What are cations?Cations are said to be the ions formed by donating their outermost valence electron that in return results in a positive charge on the element. Cations are said to be formed when the electron is more in number in the valence shell.
The electronic configuration is given as:
Lithium - 2, 1Sodium - 2, 8, 1Potassium - 2, 8, 8, 1Here, there is one electron extra in the outer shell of the atom that can be donated to other atoms that are called anions (electron acceptors). Li, Na, and K can donate one electron each and hence will acquire a +1 charge.
Therefore, option C. lithium, sodium, and potassium form a +1 charge.
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The overall reaction in a commercial heat pack can be represented as How much heat is released when 4.40 moles of iron are reacted with excess ? Heat = kJ How much heat is released when 1.00 mole of is produced? Heat = kJ How much heat is released when 1.60 g iron is reacted with excess ? Heat = kJ How much heat is released when 11.8 g and 1.20 g are reacted? Heat = kJ
Answer:
Explanation:
The overall equation for this reaction can be represented as:[tex]4 Fe(s) + 3 O_{2(g) } \to 2Fe_2O_{3(s)} \ \ \ \ \Delta H = -1652 \ kJ[/tex]
The first question says:
How much heat is released when 4.40 moles of iron is reacted with excess O₂?
Suppose 1652 kJ of heat is being emitted into the surroundings when four(4) moles of Fe reacted with O₂, therefore;
4.40 moles of Fe reacts with:
[tex]=\dfrac{4.40 \ moles \times 1652 \ kJ}{4 \ moles}[/tex]
= 1817.2 kJ of heat will be produced.
The second question says:
How much heat is released when 1.00 mole of [tex]Fe_2O_3[/tex] is produced?
Given that 1652 kJ of heat is being emitted into the surroundings when two(2) moles of [tex]Fe_2O_3[/tex] is produced, therefore;
1.00 moles of [tex]Fe_2O_3[/tex] reacts with:
[tex]=\dfrac{1.00 \ moles \times 1652 \ kJ}{2 \ moles}[/tex]
= 826 kJ of heat will be produced.
To the third question; we have:
How much heat is released when 1.60 g iron is reacted with excess O₂?
We need to find the number of moles of iron first.
We know that number of moles = mass/molar mass
Thus, the molar mass of iron = 55.8 g/mol
number of moles of iron = (1.60g) / (55.8 g/mol)
number of moles of iron = 0.02867 mol
Thus; [tex]\dfrac{0.02867\ mol \times 1652 \ kJ }{4 \ mol}[/tex]
= 11.84 kJ of heat is released.
The last question says:
How much heat is released when 11.8 g Fe and 1.20 g O₂ are reacted?
Again;
the number of moles of Fe = (11.8g) / (55.8 g/mol) = 0.2114 mole of Fe
Thus; [tex]\dfrac{0.2114\ mol \times 1652 \ kJ }{4 \ mol}[/tex]
= 87.31 kJ of heat is released.
On the other hand,
the number of moles of O₂ = (1.20g) / (32 g/mol) = 0.0375 mol of O₂
Thus; [tex]\dfrac{0.0375\ mol \times 1652 \ kJ }{3 \ mol}[/tex]
= 20.65 kJ of heat is released
Therefore, when these two(2) reactants reacted with each other, it is just the smaller amount of heat that would be released because oxygen tends to be the limiting reactant.
Which student was practicing poor laboratory safety?
Gunther read all the safety precautions for an experiment and collected his chemicals.
Herbert started mixing his chemicals as the teacher began explaining the lesson.
Francine washed her hands after spilling table salt on them.
Reilly tied her hair back into a ponytail after putting on her lab coat.
Answer herbert
Explanation:
cause he did not do any of the safety precautions and he was prob not listening to the teacher
Help me answer the question please I don’t get it this is earth science not chemistry.
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Question 2 of 11
Which of these are part of a scientific way of gathering information?
A. Fairy tales
B. Religious beliefs
C. Investigations
D. Opinions
SUBMIT
Answer:
C
Explanation:
the rest arent scientific
Answer:
C. Investigations
Explanation:
Test approved
In which ocean zone would photosynthetic organisms be found?
Answer:
Photic Zone
Explanation:
The photic zone is the uppermost layer of the sea that recieves sunlight allowing phytoplankton to perform photosynthesis.
I hate chemistry please help
Answer:
Love it because Love it
Explanation:
Draw a structural formula for the alkene you would use to prepare the alcohol shown by hydroboration/oxidation.
Answer:
See explanation
Explanation:
The question is incomplete because the image of the alcohol is missing. However, I will try give you a general picture of the reaction known as hydroboration of alkenes.
This reaction occurs in two steps. In the first step, -BH2 and H add to the same face of the double bond (syn addition).
In the second step, alkaline hydrogen peroxide is added and the alcohol is formed.
Note that the BH2 and H adds to the two atoms of the double bond. The final product of the reaction appears as if water was added to the original alkene following an anti-Markovnikov mechanism.
Steric hindrance is known to play a major role in this reaction as good yield of the anti-Markovnikov like product is obtained with alkenes having one of the carbon atoms of the double bond significantly hindered.
Xenon is an element similar to Neon. Its density can be found on the Reference Table. Convert Xenon’s density to scientific notation.
The Scientific Notation of Xenon’s density : 1.31293 × 10²
Further explanationScientific Notation consists of 2 parts
1. the first part: the first digit followed by the decimal point
2. The second part: the power of 10 which shows the number of digits after the decimal point
Xenon's density = 131.293
First digit = 1, then we give the decimal point and the next digit
The power of 10 is determined from the number of decimal points moved from the original decimal point
Because we move the decimal point two digits to the left, the power of 10 has the number 2 (10²)
So that the Scientific Notation form becomes:
1.31293 × 10²
Once upon a time, I was traveling from Kaunas Lithuania to Klaipeda to see Egle, the queen of serpents. Being the queen of serpents, she has certain magical powers. In exchange for some sand, salt, and iron, she will grant my wish. I put all three things in my bottle together and traveled. During my travels, the salt, sand, and iron got mixed up. No big deal right? Wrong. Egle wants each thing separated before she will grant my wish.... Am I just out of luck completely?
Please write your response and explain your reasoning.
Answer:
No
Explanation:
Fortunately, in this scenario, you are not out of luck. Each of these components has a unique trait that would allow you to easily separate them. For starters, you can separate all of the Iron with a strong magnet since iron has a magnetic field while sand and salt do not. Next, you can separate the salt and sand by adding water since salt will dissolve in the water leaving only the sand which is not soluble. Once the sand is removed you would simply need to distill the water/salt mixture which would separate the salt from the water. Now you have all three components separated and can get your wish.
What can you conclude from the fact that scientists continue to update the atomic model?
A
New information about atoms continues to be discovered
B
Old information about atoms is completely useless
С
Scientists did not have any information about atoms until a few years ago
D
Scientists still have no idea what atoms look like
Answer:
A
Explanation:
B,C,D is incorrect about atomic model
Light travels at a speed of 3.00 x 100 ^10 cm/s. What is the speed of light in kilometers/hour?
Answer:
1.1 x [tex]10^{9}[/tex] km/h
Explanation:
Here we need to do two conversions- one from centimetres to kilometres and one from seconds to hours.
To get from cm to km- we divide by 100 000 since there are 100 000 cm in a km.
To get from seconds to hours we divide by 3600 since there are 3600 seconds in an hour
[tex]\frac{3*10^{10}cm/100000 }{1second/3600} =1.1*10^{9} km/h[/tex]
I need help, plz and thank you.
In 1973, the insecticide called DDT wasbanned in the United States due to concerns that itwas toxic to fish and that it may have affected birds.There is little scientific evidence that DDT is directlyharmful to humans. How could banning DDT be beneficial to human health
Answer:
See explanation
Explanation:
DDT is dichlorodipphenylrtrichloroethane. It is was a popular insecticide used for agricultural purposes. Racheal Carson's book, silent springs drew attention to the use of insecticides such as DDT in agriculture.
DDT is a non-biodegradable, fat-soluble compound. It enters into the food chain and has the ability to bioaccumulate in the human body where it becomes deposited in the adipose tissue.
There is no direct harmful effect of DDT to humans, however, when oxidation of DDT takes place in body many harmful metabolites are released into the body causing harmful effects to human health such as; breast cancer, male infertility, miscarriages and low birth weight, developmental delay and liver damage.
There is convincing empirical evidence supporting the carcinogenicity of DDT its main metabolites DDE and DDD, however, many studies on the harm caused by DDT and its main metabolites in the body have so far led to inconclusive, and sometimes negative, results
what is called when a paragraph studies data carefully
✅Paraphrasing and summarizing .✅
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