Answer all the following questions by putting a circle around a letter A.B.C or D
1. Air contains about
A. 3% carbon (IV) oxide.
B. 4%noble gases.
C. 21%oxygen
D. 69% nitrogen
Answer:
C. 21%oxygen
Explanation:
Dry air contains 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.
"A bicycle's brakes apply 299 N of frictional force to the wheels as the bike moves 24 m
for 3.0 s. How much WORK do the brakes do?"
Answer:
0.62 N
Explanation:
first of all: 3.0 s = 0.05 m
Let ? be the work that brakes do at 3.0s
24 m ----> 299 N
0.05 m ---->?
? = (0.05 m x 299 N)/ 24
? = (14.95)/ 24
? = 0.622 N
can someone help me with this will mark brainliest
Answer:
3
Explanation:
Which is a form of kinetic energy?
A. gravitational energy
B. chemical energy
C. electrical energy
D. sound energy
how to write an table of content
The percent by mass of iron(III) 1 Fe2S3
is _____%
Answer:
percent=69.94%
What is the main gas in our atmosphere?
Answer:
Nitrogen
Explanation:
Answer:
Yes, its nitrogen. I wrote my answer earlier in the wrong spot.
Explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.
what changes chemical energy to something you can use
based on the law of conservation of energy its it atoms hold by strong chemical bonds
Please help me with my homework thanks
Answer:
electrons are transferred from the clouds to the grounf
Explanation:
Answer:
the answer is circle 3 hope it helps
Pls help me over here
Answer:
1 and the element is hydrogen (there is an exception for the octet rule for the element hydrogen) hope this helps
Explanation:
find the sum of 15, 9, 3, ....... 45
Answer:
hope this helps
Explanation:
72
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Answer:
b
Explanation:
Which statement BEST describes why licensed health care workers are held to a higher standard?
A. They agree to ethical standards when they are licensed.
B. They agree to be good role models and always model good habits.
C. They are more involved than the public.
D. They are more educated than most of the public.
Answer:
They agree to ethical standards when they are licensed.
Explanation:
Answer:
C) They agree to ethical standards when they are licensed
Explanation:
3. The complex ion Co(H2O)6 2(aq) is pink when placed in solution. Addition of chloride ions creates an equilibrium with CoCl42- in the solution, which is blue in color. Write the balanced equation for the equilibrium. If CoCl42- solubility is endothermic, predict what will happen to the solution color if the solution is heated. What will happen if the solution is cooled
Answer:
See explanation
Explanation:
When the complex ion Co(H2O)6 2+(aq) is placed in solution and chloride ions are added, the following equilobrium is set up;
Co(H2O)62+(aq) + 4 Cl-(aq) <=> CoCl42-(aq) + 6 H2O(g)
Co(H2O)6 2+(aq) solution is pink in colour while CoCl42-(aq) solution is blue in colour.
Since the solubility of CoCl42-(aq) is endothermic, heating the solution will move the equilibrium position towards the right (more CoCl42-(aq) is formed and the solution is blue in colour).
When the solution is cooled, more Co(H2O)62+(aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in colour.
When the solution is cooled, more [tex]Co(H_2O)_6^{2+}[/tex] (aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in color.
Balanced equation for the equilibrium:When the complex ion [tex]Co(H_2O)_6^{2+}[/tex] (aq) is placed in solution and [tex]CoCl_4^{2-}[/tex] are added, the following equilibrium is set up;
[tex]Co(H_2O)_6^{2+}(aq) + 4 Cl^-(aq) < = > CoCl_4^{2-}(aq) + 6 H_2O(g)[/tex]
[tex]Co(H_2O)_6^{2+}[/tex] (aq) solution is pink in color while [tex]CoCl_4^{2-}[/tex](aq) solution is blue in color. Since the solubility of [tex]CoCl_4^{2-}[/tex](aq) is endothermic, heating the solution will move the equilibrium position towards the right (more [tex]CoCl_4^{2-}[/tex] (aq) is formed and the solution is blue in color). When the solution is cooled, more [tex]Co(H_2O)_6^{2+}[/tex] (aq) is formed and the equilibrium position shifts towards the left and the solution becomes pink in color.
Find more information about Equilibrium here:
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I need help plzzzzzz
Answer:
it is 25%
Explanation:
Answering so you can give the other person brainliest :D have a good day
what is Determine the mass of 2.40 moles of CoH12
Answer:
mass of CO 2 = M r x number of moles of CO 2 = 44.0 × 0.010 = 0.44 g
Explanation:
If you have 9.56 moles of aluminum oxide how many moles of sodium oxide could you produce?
Answer:
The answer is 28.68 moles
Explanation:
Hope this helped Mark BRAINLEST!!!
A burning match will burn more vigorously in pure oxygen than in air because _________ . Select one: a. oxygen is a catalyst for combustion b. nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion c. oxygen is a product of combustion d. nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature e. oxygen is a reactant in combustion and pure oxygen increases the reactant concentration
Answer:
e. oxygen is a reactant in combustion and pure oxygen increases the reactant concentration
Explanation:
The reaction of a burning match is combustion. In this combustion, the organic components of the match (such as cellulose, C₆H₁₀O₅) react with oxygen, producing water and carbon dioxide:
C₆H₁₀O₅(s) + 6O₂(g) → 5H₂O(g) + 6CO₂(g)Seeing as oxygen is a reactant and not a catalyst nor product, and that nitrogen plays no part in the reaction, the only correct answer is option e.
What is the purpose of the scientific method?
A. To use an experiment to test a scientific theory
B. To make a guess in order to prove a hypothesis
C. To remove any source of bias in an experiment
D. To provide a reliable answer to a specific question
Answer:
B. To make a guess in order to prove a hypothesis.
Explanation:
What is the mass percentage of calcium in calcium carbonate CaSO4?
Which type of rock does Florian predict these pieces will change into when subjected to heat and pressure?
Answer:
The Florian predict the metamorphic rocks because it changes when subjected to heat and pressure.
Explanation:
i hope this helps
Which of the following is an example of water in its gas state?
1. A puddle
2. Water vapor
3. A glacier
4. A cloud
pls be fr will mark brainliest
Answer:
1. The two gases making the highest relative contribution to the greenhouse gases are: "CO2 and CH4."
2. The effect of increasing amount of greenhouse gasses is: "All of the above"
3. Which one of the following is a wrong statement?: "Eutrophication is a natural phenomenon in freshwater bodies"
4. The major contributors to the greenhouse gases are: "All of the above"
Explanation:
CO2 is carbon dioxide, and CH4 is methane. Also, the greenhouse gas effect is natural, except, the amount of greenhouse gases is not.
2KCIO3 -2KCL + 302
Use the balanced chemical equation to solve the following problems. Show all work and answer with the correct units and significant figures.
a. How many moles of oxygen are produced if 4 moles of potassium chlorate decomposes?
b. If 4.5 moles of potassium chloride are produced, how many molecules of oxygen gas are also produced?
c. If 5.0 g of potassium chlorate decomposes, how many grams of potassium chloride are produced?
Answer:
a. 6 moles of O₂
b. 4.06×10²⁴ molecules of O₂
c. 3.04 g of KCl
Explanation:
Reaction of decomposition is:
2KClO₃ → 2KCl + 3O₂
a. See stoichiometry value
2 moles of potassium chlorate can decompose to 2 moles of potassium chloride and 3 moles of oxygen. Ratio is 2:3
If 2 moles of KClO₃ can decompose to 3 moles of O₂
Then 4 moles, may decompose to (4 . 3)/2 = 6 moles of O₂
b. In this case, the stoichiometry is the same.
Per 2 moles of KClO₃, I produce 2 moles of KCl
Then, 4.5 moles of KCl, were produced by 4.5 moles of KClO₃
We apply, the last relation:
(4.5 . 3) /2 = 6.75 moles of O₂ are also produced.
How many molecules are in 6.75 moles?
6.75 mol . 6.02×10²³ molecules/mol = 4.06×10²⁴ molecules of O₂
c. First of all, we convert the mass to moles:
5g . 1mol /122.55g = 0.0408 moles of salt
As ratio is 2:2, 0.0408 moles of salt, decompose to 0.0408 moles of KCl
We convert the moles to mass: 0.0408 mol . 74.55g /mol = 3.04g
HELPPP PLZZZZ NOWWW !!!!!!!
What happens when a gas is heated
Answer:
The particles' kinetic energy is increased, allowing the gas to expand. When a gas is heated the volume will increase when gas is increased....
If 7.0 moles of HCl is added to enough iron that the HCl is completely used up, how many
moles of hydrogen gas will be produced?
Answer:
3.5 mol
Explanation:
Step 1: Given data
Moles of HCl: 7.0 mol
Step 2: Write the balanced equation
Fe(s) + 2 HCl(aq) ⇒ FeCl₂(aq) + H₂(g)
Step 3: Calculate the moles of H₂ gas produced from 7.0 moles of HCl
According to the balanced equation, the molar ratio of HCl to H₂ is 2:1.
7.0 mol HCl × 1 mol H₂/2 mol HCl = 3.5 mol H₂
which statement describes the process of budding
Answer:
Budding, in biology, a form of asexual reproduction in which a new individual develops from some generative anatomical point of the parent organism. ... The initial protuberance of proliferating cytoplasm or cells, the bud, eventually develops into an organism duplicating the parent.
Explanation: im not sure if this will help because you didnt give any statements.
Answer: Cell division with mitosis causes new individuals to develop on a parent.
Explanation: did the test A.P.E.X. hope this helps <3
How do the polar easterlies and the jet stream work together to affect the
weather in the United States?
Answer:
they can carry cold arctic air, producing snow and freezing weather.
Explanation:
-w- hope it helps
Please help me, I can't figure this out. You have a 450.0 mL balloon filled with 0.0184 moles of Helium gas. The volume of the balloon will change, but the pressure of the gas inside will always match the 1.00 atm pressure outside. If the balloon is kept at a constant 25oC, how many moles of gas must you remove to shrink the balloon down to 200.0 mL?
Answer and Explanation:
V1/n1 = V2/n2
450.0 mL / 0.0184 mol = 200.0 mL / n2
n2 = 8.17X10^-3 mol
moles removed = 0.0184-8.17X10^-3 = 0.0102 mols removed, I think I'm right but I'm not 100% sure..
According to Avogadro's law, 0.008 moles of gas must be removed to shrink balloon to 200 ml.
What is Avogadro's law?Avogadro's law is a gas law which states that the total number of atoms or molecules has a direct proportion to the volume occupied by a gas at a constant temperature and pressure.
It is closely related to ideal gas equation as it links temperature, pressure, volume and the amount of substance.It is given as, V∝n,
The straight line graph of volume versus moles is a straight line passing through the origin which implies that zero moles of gas occupy zero volume.
Here, the number of moles is calculated as, V₁/n₁=V₂/n₂
Therefore on substitution, n₂=0.0184×200/450=0.008 moles.
Thus,0.008 moles are required to shrink the balloon to 200 ml.
Learn more about Avogadro's law,here:
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