Answer:
energy leaves the chemical and heats up the surrounding area
Explanation:
In the reaction given below, 23.5 grams of iron(III) oxide (Fe2O3) are reacted with excess carbon. What is the theoretical yield of iron metal?
2 Fe2O3 + 3 C --> 4 Fe + 3 CO2
If 14.5 grams of iron are recovered when the reaction is complete, what is the percent yield?
**Both answer should be written as XX.X
Answer:
Theoretical yield = 16.76 g
Percent yield = 87%
Explanation:
Given data:
Mass of iron oxide = 23.5 g
Theoretical yield of iron = ?
Actual yield of iron = 14.5 g
Percent yield of iron = ?
Solution:
Chemical equation:
2Fe₂O₃ + 3C → 4Fe + 3CO₂
Number of moles of iron oxide:
Number of moles = mass/molar mass
Number of moles = 23.5 g/ 159.69 g/mol
Number of moles = 0.15 mol
Now we will compare the mole of iron oxide with iron metal.
Fe₂O₃ : Fe
2 : 4
0.15 : 4/2×0.15 = 0.3
Mass of iron:
Mass = number of moles × molar mass
Mass = 0.3 mol × 55.85 g/mol
Mass = 16.76 g
Percent yield:
percent yield = (actual yield / theoretical yield)× 100
Percent yield = (14.5 g / 16.76 g) × 100
Percent yield = 0.87 × 100
Percent yield = 87%
Answer:
I tried the answer above and it’s correct
Explanation:
Use the model to answer the question.
Which element symbol actually represents the model?
Plz answer
Answer:
B
Explanation:
Boron has 5 protons.
We can change the substance chemically by
freezing it.
True or false
Use your answers from questions 1–3 as the basis for the first section of your lab report. This section provides your reader with background information about why you conducted this experiment and how it was completed. Outline the steps of the procedure in full sentences. It also provides potential answers (your hypothesis/es) relative to what you expected the experiment to demonstrate. This section should be 1–3 paragraphs in length.
Answer:
1-state what the lab is about, that is, what scientific concept (theory, principle, procedure, etc.) you are supposed to be learning about by doing the lab. You should do this briefly, in a sentence or two. If you are having trouble writing the opening sentence of the report, you can try something like: "This laboratory experiment focuses on X…"; "This lab is designed to help students learn about, observe, or investigate, X…." Or begin with a definition of the scientific concept: "X is a theory that…." 2-give the necessary background for the scientific concept by telling what you know about it (the main references you can use are the lab manual, the textbook, lecture notes, and other sources recommended by the lab manual or lab instructor; in more advanced labs you may also be expected to cite the findings of previous scientific studies related to the lab). In relatively simple labs you can do this in a paragraph following the initial statement of the learning context. But in more complex labs, the background may require more paragraphs.
Explanation:
Answer: the correct answer is A
Explanation:
An independent variable is....
A: What we measure
B: What we change
C: What stays the same
D: What we conclude
Answer:
B - What we change
Explanation:
Dependent Variable - What we measure
Control Variable - what stays the same
Conclusion - what we conclude
Hope this can Help!
:D
What will happen to the flow of blood in blood vessels (pulse) if heart beat rate increase
Answer:
"Low levels of the hormone epinephrine, also called adrenaline, cause blood vessels to relax and widen. High levels of this same hormone, along with the hormone norepinephrine, cause the blood vessels to narrow and the heart rate to rise, increasing blood pressure."
Explanation:
Identify a metal from the following
(1) Sulphur
(2) Boron
(3) Silicon
(4) Sodium
Answer:
sodium
Explanation:
it is an alkali metal
1. Why is soil erosion relatively less in dense forests as compared to barren, open fields?
Because the deep roots of big trees hold the soil and don't let it slip away simply by rain or wind.
Answer:
the roots of the trees keep the soil in place opposed to a barren landscape that has little to no plants to keep the soil in place
hope this helps (╹ڡ╹ )
Which of the following is an indication of a physical change?
O A. The formation of a new substance
O B. Giving off a smell
O C. A change in the shape of a substance
O D. The production of gas and heat
Answer:
A change in the shape of a substance
Explanation:
Because when ths shape of a sunstance changes , its physical appearance changes .A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
If 150 G of war started burning 300 G of where as was left behind how many grams of CO2 gas is released
Answer:
geruow0irghvn3p0unhie0ghik
Explanation:
2 of 4
+ Automatic Zoom
10. The molar mass of CS2 is 76.14 g/mol. How many grams of CS2 are present in 10.00 mol?
Answer: C
Explanation:
There are 761.4 grams of CS2 in 10.00 mol.
To calculate the amount of grams present in a given amount of moles, the molar mass of the substance must be used, as follows:
[tex]m = MM \times mol[/tex]
In this way, just perform the following operation:
[tex]m = 76.14 \times 10[/tex]
[tex]m = 761.4 grams[/tex]
Thus, there are 761.4 grams of CS2 in 10 mol of the substance.
Learn more about mole calculation in: brainly.com/question/15693285
A neutral atom contains 12 neutrons and 11 electrons. The number of protons in this atom is
(1) 1 (3) 12
(2) 11 (4) 23
Answer:
1
Explanation:
Which of the following subatomic particles are found surrounding the nucleus and have a negative charge?
F negatrons
G neutrons
H protons
J electrons
Answer:
J electrons
Explanation:
Electrons are the negatively charged subatomic particles that surrounds the nucleus of an atom.
Electrons occupy the bulk volume of an atom. These particle was discovered by J.J ThomsonThey found orbiting the extra-nuclear space of every atom. The nucleus is made up of protons and neutrons.Which of these ions has the correct charge?
O2-
B2+
P2-
Li2+
Answer:
02- i think your welcome hope it helps
Which of the following most likely happens when thermal energy is removed from a chemical reaction?
Answer:
fewer collisions occur between particles or lowering the temperature
Explanation:
Can someone help? Ill give brainliest!
Directions: count each side of the reaction then Circle yes or no if it follows the law of conservation of mass
Answer:
Explanation:
before the reaction you have K=2 and Cl=4
after the reaction K=2 and Cl=2 so it does not follow the law of conservation
Plzzzzzzzz help Which species is a index fossil
Answer:
e
Explanation:
it's in the index fossil range
Answer:
Explanation:
In marine strata, index fossils that are commonly used include the single-celled Protista with hard body parts and larger forms such as ammonoids. In terrestrial sediments of the Cenozoic Era, which began about 65.5 million years ago, mammals are widely used to date deposits.
2. How can glass be a liquid if it's so hard?
Explanation:
Glass is not a liquid in the strictest sense of the word. But it is also not a standard solid. The chemistry of glass is complex and research is ongoing, but the current consensus is that glass is a phase of matter all its own, known as an "amorphous solid". Scientists refer to any amorphous solid as a "glass". Glass transitions are highly complex and cannot be treated in the same way as traditional phase transitions.
Answer:
It's a liquid state before its cooled.
please help I need to ace this test
When two atoms attach to each other by sharing electrons it is called a...
A: Covalent bond
B: Ionic bond
C: none of these - atoms can't bond to each other.
D: Nuclear bond
2nd question
Two hydrogen atoms bonded together form a compound
A: True
B: False
3rd question
Water is two hydrogen atoms bonded to an oxygen atom. This is an example of a compound
A: True
B: False
like I said I need help on this and I don't wanna fail
#1: A covalent bond
#2 False
#3True
how to know the unknown metal in flame test
Explanation:
The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light
Help me with homework.
The chemical equation is said to be balanced if the number of atoms in the reactants and products is the same
Further explanationEquation balanced ⇒ total number of atoms in reactants(on the left)= total number of atoms in products(on the right)
H₂+O₂---> H₂O
Reactants : H₂, O₂
Products : H₂O
not balanced
H₂O₂ ---> H₂O+O₂
Reactants : H₂O₂
Products : H₂O, O₂
not balanced
Na+O₂ ---> Na₂O
Reactants : Na, O₂
Products : Na₂O
not balanced
N₂+H₂ ---> NH₃
Reactants : N₂, H₂
Products : NH₃
not balanced
P₄+O₂---> P₄O₁₀
Reactants : P₄, O₂
Products : P₄O₁₀
not balanced
Fe+H₂O ----> Fe₃O₄ + H₂
Reactants : Fe, H₂O
Products : Fe₃O₄
not balanced
Which screw would create a strong hold?
A: The screw with 9 wraps.
B: The screw with 2 wraps.
C: The screw with 10 wraps.
D: The screw with 6 wraps.
Answer:
The screw with 10 wraps is the correct answer
Explanation:
The screw with 6 wraps would create a strong hold.
What do you mean by screw?The strongest member of the family of wood screws is a lag screw. It is a reliable and sturdy fastener that frequently has a square head or an externally powered hex drive.
In general, lag screws are significantly stronger and heavier than standard wood screws. They have a tapered point and coarse threads.
Thus, The screw with 6 wraps would create a strong hold.
To learn more about Screw, refer to the below link:
https://brainly.com/question/24168324
# SPJ5
Which of the following best describes a hypothesis?
A. An explanation that is supported by scientific data
B. A proven explanation for experimental results
c. A possible answer to a scientific question
D. A question about the natural world
please help i will give brainliest
if the atomic mass is 14 and the atomic number is 7,how many neutrons do you have?
Answer: 7 neutrons
Explanation: Atomic number refers to the number of protons in the nucleus of the atom. Also you can treat atomic mass as how many particles (protons and neutrons) are in the nucleus of the atom. So for this problem:
14 particles - 7 protons = 7 neutrons (and we know all that's left over is neutrons because we subtracted all the protons)
How is the process of photosynthesis essential to sustaining life on Earth?
Answer:
Explanation:
Photosynthesis is important to living organisms because it is the number one source of oxygen in the atmosphere. Without photosynthesis, the carbon cycle could not occur, oxygen-requiring life would not survive and plants would die. ... The importance of photosynthesis in our life is the oxygen it produces
how many sig figs are in 0.0093
Answer:
there are two significant figures
Explanation:
Answer:
there are two
Explanation:
because the zeros dont count
How many moles of Cl2 are needed in order to produce 100.0 grams of FeCl3 given the following
equation: 2 Fe + 3 Cl2 → 2 FeCl3
B
T
Answer:
0.92moles
Explanation:
Given reaction:
2Fe + 3Cl₂ → 2FeCl₃
Mass of FeCl₃ = 100g
Unknown:
Number of moles of Cl₂ needed = ?
Solution:
To solve this problem, we work from the known specie to the unknown.
From the mass of the FeCl₃ given, we can solve for the number of moles of the unknown.
Number of moles of FeCl₃;Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of FeCl₃ = 56 + 3(35.5) = 162.5g/mol
Number of moles = [tex]\frac{100}{162.5}[/tex] = 0.62mole
From the reaction expression;
2 mole of FeCl₃ is produced from 3 moles of Cl₂
0.62 mole of FeCl₃ will be produced from [tex]\frac{0.62 x 3}{2}[/tex] = 0.92mole
The number of moles of Cl₂ = 0.92moles
The specific heat of a certain type of metal is 0.128 J/(g⋅∘C). What was the intial temperature if 0.305 kJ of heat is added to 94.8 g of metal to reach a temperature of 85.0 ∘C?
The intial temperature : 59.865 °C
Further explanationHeat added :
Q = m . c . ΔT
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
[tex]\tt 305=94.8\times 0.128\times (85-t_1)\\\\85-t_1=25.135\\\\t_1=59.865^oC[/tex]
You are doing math homework and get frustrated and throw the 7 kg book with a force of 47
Newtons. How much acceleration will the book have when you throw it?
Answer:
The answer is 6.71 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
f is the force
m is the mass
From the question we have
[tex]a = \frac{47}{7} \\ = 6.714285...[/tex]
We have the final answer as
6.71 m/s²Hope this helps you
When 0.25 moles of NH3 are produced according to the reaction below, how many moles of H2 must have reacted?
N2 + 3 H2 --> 2 NH3
O 1.5 moles H2
O 0.38 moles H2
O 0.25 moles H2
O 0.17 moles H2
Answer:
Explanation:
by stoichiometry
nNH3/2=nH2/3
0.25/2=nH2/3
nH2=0.25×3/2
nH2=0.375 mol
so its 0.38 mol
Answer:
I have this quiz rn I will try 0.38 if it is right I’ll edit this and say that
Explanation: