in which time period did the first animals that could live both in water and on land appear
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Answer:
1) actual yield - 2.675 g
Theoretical yield - 4.0539 g
2)a) 41.257 g
b) 0.6857moles
c) 23 g
Explanation:
1)
Theoretical yield is the mass of the product that can obtain from the equation, it is not practical.
Theoretical yield:
Mr of SiO2 - 60
Moles of SiO2 - 2.339/60 = 0.03898 moles
Mr of SiF4 - 104
Mass of SiF4 - 0.03898 * 104 = 4.05392 g
2)
a)
mr of B2H6 - 28
Moles of B2H6 - 36.1/28 = 1.2893 moles
Mr of O2 - 32
Mass of O2 - 32 * 1.2893 = 41.257 g
b)
Moles of B2H6 - 19.2/28 = 0.6857 moles
Stoichiometry 1:1 ratio between B2H6 and H2O
So moles of H2O is 0.6857
c) moles of O2 - 2/24(r.t.p) = 0.083 moles
Mass of B2H6 - 0.083 * 28 = 2.3 g
how long would it take to electroplate a flute with 28.3 g of silver (107.87 g/mol) at a constant current of 2.0 amps using AgNO3
It would take 211 hours to plate 28.3 g of silver on a flute.
The equation of the reaction;
Ag^+(aq) + e -----> Ag(s)
We know that 1 F of electricity is required to deposit 107.87 g of Ag. Also 1F = 96500 C
Now;
Since 107.87 g is deposited by 96500 C of electricity
28.3 g is deposited by 28.3 g × 96500 C/ 107.87 g
= 25317 C
Also;
Q = It
I = current
t = time
25317 C = 2.0 amps × t
t = 25317 C /2.0 amps
t = 12658.5 seconds or 211 hours
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Answer:
It would take [tex]3.5hrs[/tex] to electroplate the fluteExplanation:
Electrolysis equation is:
[tex]Ag1+ + 1e- ------> Ag[/tex]
1 mol of Ag requires 1 mol of electron
1 mol of electron = 96485 C
So,
1 mol of Ag requires 96485 C
let us calculate mol of element deposited:
molar mass of Ag = [tex]107.87 g/mol[/tex]
number of mol of Ag, [tex]n = \frac{mass of Ag}{molar mass of Ag}[/tex]
[tex]n = \frac{28.3}{107.87}\\\\n = 0.2623 mol[/tex]
[tex]total charge = mol of element deposited * charge required for 1 mol\\\\total charge = 0.2623*9.649*10^4\\\\total charge = 2.531*10^4 C[/tex]
Therefore,
[tex]time = \frac{Q}{i}\\\\= \frac{2.531*10^4}{2}\\\\= 1.265*10^4 seconds\\\\= 3.515 hr[/tex]
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A Herbig-Haro (HH) object is:_:_________.
a. a small galaxy just outside the outer edge of the Milky Way
b. where a jet from a star in the process of being born collides with (and lights up) a nearby cloud of interstellar matter
c. a part of a giant molecular cloud where molecules containing two hydrogen atoms form
d. a star that has too little mass to start fusion in its core
e. cluster of very low-mass stars, observable only with infrared radiation
Given what we know about Herbig-Haro (HH) objects, we can confirm that they are born from the collision between a jet from a star and clouds of interstellar matter.
What are Herbig-Haro (HH) objects?To put it simply, a Herbig-Haro (HH) object is what we observe as a bright spot in distant space. Upon closer observation we can observe that these giant bright patches are not lone objects, but in fact immense groups of interstellar matter. How Herbig-Haro (HH) objects are formed.The formation of one of these interstellar groups requires an immense amount of energy. This energy come from the speed at which the materials that form these objects collide.As stated in the question, the jet released from a star in the process of being born smashes into a giant cloud of dust and interstellar material to form the Herbig-Haro (HH) objects. This collision happens at hundreds of km/s. To put it into perspective, it would be roughly 500,000 miles per hour.Therefore, we can confirm that option b, which states, "where a jet from a star in the process of being born collides with (and lights up) a nearby cloud of interstellar matter", is the correct choice for the question pertaining to Herbig-Haro (HH) objects.
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Based on the graph, what is the approximate half-life of the reaction shown below
Answer: 2.1 minutes
Explanation: Based on the graph, what is the approximate half-life of the reaction shown below
What is the amplitude of the above wave?
Answer:Amplitude in a longitudinal wave
Explanation:Wave amplitude of a longitudinal wave is the distance between particles of the medium where it is compressed by the wave. Wave amplitude is determined by the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude.
I need help, plz help me with this problem
Answer:
It's b
Explanation:
I had the same exact question
what is the chemical formula of tetraphosphorus heptasulfide?
Answer: P4S7
Explanation:
Question 5 (Fill-In-The-Blank Worth 2 points)
(03.05 LC)
The number that represents a neutral pH is _______.
Numerical Answers Expected!
Answer for Blank 1:
Question 6(Multiple Choice Worth 2 points)
(03.05 MC)
Which item is made from an acidic ingredient?
Detergent
Soap
Ammonia
Vinegar
Question 7(Multiple Choice Worth 2 points)
(03.05 MC)
Which substances will make a salt when combined?
Vinegar and tea
Soda and wine
Soda and ammonia
Fertilizer and detergent
Question 8(Multiple Choice Worth 2 points)
(03.05 MC)
Which description is not a property of an acid?
pH lower than 7
Turns litmus paper blue
Sour taste
Corrosive
Question 9(Multiple Choice Worth 2 points)
(03.05 MC)
Complete the sentence. When an acid is added to water, hydrogen ions __________.
increase
decrease
stay the same
disappear
A calcium atom has 20 protons, 20 electrons, and 20 neutrons. When calcium forms a positive two ion it's new composition is
Answer:
40
Explanation:
I'm not sure
Why is the molecule not an example of a cis stereoisomer
Answer:
Because in order to have cis or trans configuration both carbon of alkene need to have a hydrogen
How do covalent compounds differ from ionic compounds?
Answer:
1. Ionic bonds result from transfer of electrons, but covalent bonds are formed by sharing.
2. Ions are arranged in a three-dimensional array (like crystals). Covalently bonded substances exist as discrete molecular units.
3. Ionic compounds often dissociate into ions in solution, but covalently bonded molecules retain their molecular identity in solution.
Hope this helps :)
What is the molarity of a 75.0 mL solution that contains 0.225 g of
potassium nitrate?
Answer:
M=0.0297M
Explanation:
we know that molarity equals number of mole of solute over the volume of solution.
M=n/V but n=m/M
n=0.225g÷101g/mol =0.00223mol
M=0.00223mol/0.075l
M=0.0297M
Answer:
0.0297M
Explanation:
We will use the formula M= moles of solute/lites of solution.
First we need to figure out the Moles of the solute, to get this we first need the molar mass of KNO3 (potassimum nitrate).
The Molar Mass of potassimum nitrate is 101.103 g/mol
K - 1 x 39.09
N - 1 x 14.006
O - 3 x 15.999
KNO3 - 101.103 g/mol
Now we get the moles of the solute by doing.
0225g/ 101.103g/mol = 0.00223 mol
Put the answer into the orginal equation to get 0.00223mol / 0.045 L
Which equals to 0.0297M. This is also the correct amount of significant figures.
what is mass tbh pls he;p
Answer:
how much matter is in an object
Explanation:
`Carbon Dioxide and Water are the _______ in a chemical reaction. 2. Reactants are also called the starting _______ in a chemical reaction.: Reactants are also called the starting _______ in a chemical reaction. 3. This type of energy comes from the sun: a This type of energy comes from the sun 4. You get this type of energy from food: b You get this type of energy from food 5. The process by which plants use the sun to produce glucose and oxygen.: The process by which plants use the sun to produce glucose and oxygen. 6. The products of photosynthesis: The products of photosynthesis 7. The location of photosynthesis in plant cells: The location of photosynthesis in plant cells 8. Another name for glucose is: Another name for glucose is 9. Energy is provided by this cell organelle during cellular respiration: Energy is provided by this cell organelle during cellular respiration 10. The largest source of energy on earth comes from the: d The largest source of energy on earth comes from the Column B a.Chloroplast b.Ingredients c.Reactants d.Sun e.Radiant energy f.Sugar g.Chemical energy h.Glucose and Oxygen i.Mitochondria j.Photosynthesis
The molecular formula for a compound with a molar mass of 180.18g that contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass is
Answer:
C6H12O6
Explanation:
First you need to find the empirical formula by the percents that they're giving you. You assume that is 100 grams and if for example you have 40% of carbon you will have 40 grams of carbon.
1.Find the number of moles of each atom
C: 40g÷12g/mol= 3.33 mol
H: 6.7g÷1g/mol= 6.7 mol
O: 53.3g÷16g/mol= 3.33 mol
You divide all ratios by the minimum ratio and you obtain the empirical formula
CH2O
Since you're given the molar mass, you now have to find the molar mass of CH2O by adding the molar mass of each element present and repeated in the compound.
CH2O= 30g/mol
Now you know that the molar mass of the molecular formula we are looking for is 180.18 g/mol, and since the empirical formula is the molecular formula in its smaller ratio, by logic you can say that:
180.18g/mol ÷ 30g/mol= 6
So, you now know that the empirical formula is being multiplied by a factor of 6 to reach a compound with a molar mass of 180.18g/mol, so you multiply each subscript of the empirical formula by 6 obtaining:
C6H12O6
A student makes an aqueous solution of sodium hydroxide. Which statement correctly identifies the two ions present in the solute of this mixture?
The sodium ion is negative, and the hydroxide ion is positive.
The sodium ion is positive, and the hydroxide ion is positive.
The sodium ion is positive, and the hydroxide ion is negative.
The sodium ion is neutral, and the hydroxide ion is neutral
The two ions present in the solution are:
1. Sodium ion, Na⁺
2. Hydroxide ion, OH¯
The correct answer to the question is the 3rd option. The sodium ion is positive, and the hydroxide ion is negative.
Ions are atoms or group of atoms which possess an electric charge.
Aqueous Sodium hydroxide, NaOH contains sodium ion and hydroxide ion.
The sodium ion is positive while the hydroxide ion is negative as illustrated below:
NaOH(aq) —> Na⁺(aq) + OH¯(aq)
From the illustration above, we can conclude that the correct answer to the question is the 3rd option. The sodium ion is positive, and the hydroxide ion is negative.
Please see attached photo for further details
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(BRAINLIEST AND 50 POINTS) no links
Name one organ system that isn't the Nervous system, Respiratory system, Skeletal system, and Circulatory system, and explain how can that system help keep you safe during a forest fire.
Answer:
Endocrine system
Explanation:
Endocrine system influences the function of the body's hormones via internal glands that are secreted into the circulatory system.
in a forest fire, your endocrine system would trigger the release of adrenaline which is the fight or flight hormone. it would affect your heart rate, metabolism, oxygen intake, and blood flow allowing you to move quicker and escape the fire
the idea of arranging the elements in the periodic table
Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
When a hurricane approaches land, people living directly on the
coast should always evacuate when told to do so by authorities.
Answer:
True
Explanation:
When a hurricane is dangerous enough that authorities say to evacuate, you should for your own safety.
What is gadolinium
And what would be a superpower that relates to it
Answer:
Chemical with symbol Gd on periodic table of elements. It reacts with oxygen.
Fire superpower i guess
Explanation:
Which best describes an element?
a pure substance
a type of a mixture
a pure compound
an impure substance
Answer:
An impure substance
Explanation:
Substance means: hard surface example: salt,corals,coal.
help me please i dont understand
Answer:
1. Dissolving powder in milk - Chemical
- It is chemical because the milk has changed on a molecular level
2. Toasting bread - Chemical
- It is chemical because adding heat to the bread cooks it, therefore
changing it on a molecular level
3. Melting cheese - Physical
- It is physical because the physical appearance was the only change
4. Slicing apples or bannanas - Physical
- It is physical because the physical appearance was the only change
5. Frying an egg - Chemical
- It is chemical because new particles were formed
6. Milk souring - Chemical
- It is chemical because it is forming a new product (lactic acid)
Explanation:
Physical Change occurs when the particles of a substance become rearranged, but do not change into different particles.
Chemical change occurs when a new substance is formed. This process is irreversable.
Answer:
give the preson above brainly bc there right
Explanation:
Earth’s layers are determined by their physical properties and chemical composition. In the lesson, you learned about each of Earth’s layers, what the layers are made of, and why they are important to the Earth. In the space below, write about how the atmosphere may be classified. Would it be part of the lithosphere, or a separate layer? Explain your answer.
Answer:
The Atmosphere Is a separate layer And Also could be classified as the Closest layer
Explanation:
 Write the chemical compounds and names for the following ionic compounds. Magnesium and phosphorus 
Answer:
Magnesium is Mg.
Phosphorus is P.
The characteristics “fingerprints” of light produced when a substance is given energy are called…
A. Groundlings
B. Quantums
C. Spectrums
D. Amplitudes
A spectrum is a pattern is unique to a substance and can be used identify it.
According to Max Plank, energy occurs in packets called quanta. Hence, energy is not continuous but takes on discrete values which are integer multiples of a fundamental amount.
Again, when a substance is given light energy, a characteristic fingerprint is obtained. This pattern is unique to the substance that has it. These characteristics “fingerprints” are called spectrums.
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Which procedures were followed in this lab to decrease experimental error? Check all that apply.
using only two types of seeds, both from the same source
having one student count every sprout in every quadrat
using adjacent plots of land for both groups
increasing the sample size by combining data from multiple groups
repeating the experiment indoors under growth lights
measuring plant height the same way and at the same time for both groups
Answer:
Basically A, C, D, F
Explanation:
Summarizing the answer
Using only two types of seeds, both from the same source.
What are experimental error?Experimental error refers to the uncertainties or mistakes that can occur during scientific experiments, leading to inaccuracies in the results. These errors can arise due to a variety of reasons, such as human error, instrumental error, environmental factors, and methodological issues. The presence of experimental error can make it difficult to draw accurate conclusions from the data obtained during an experiment.
Scientists use various procedures to reduce experimental error and improve the accuracy and reliability of their results. These procedures can include:
using adjacent plots of land for both groupsincreasing the sample size by combining data from multiple groupsmeasuring plant height the same way and at the same time for both groups.Learn more about experimental error, here:
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3 examples of how you think cells work in living things.
Answer:
Cells help the human body in many ways, Red or white blood cells are very important and are commonly spoken when bringing up cells. Plants have cells as well plant cells have special organelles called chloroplasts, which create sugars also known as photosynthesis.
Explanation:
idrk if that helped much-
Write the chemical formula for the following ionic compound nickel (III) sulfate 
Answer:
Nickel(III) Sulfate Ni2(SO4)3 Molecular Weight -- EndMemo.
Explanation:
this will explain everything
How do you prepare 500ml of 1.77M H2SO4 solution from an 18.0M H2SO4 Stock solution
Answer:
Take 49.2-ml of 18.0 M H2SO4 stock solution and pour it into a 500-ml volumetric flask. Fill to the 500-ml line with distilled water to make 1.77M H2SO4 solution.
Explanation:
use the formula M1V1=M2V2
volume must be in liters(L)
[tex](1.77)(500 \times {10}^{ - 3} ) = (18)v2 \\ 0.885 = 18v2 \\ v2 = \frac{0.885}{18} \\ v2 = 0.04916[/tex]
0.04916L × 1000 = 49.16 ml = 49.2 ml