Answer:
1.08 grams
Explanation:
first, we need to find the number of moles
we divide 12.1/22.4=0.54 moles
we multiply the number of moles with the molecular mass 0.54x2=1.08g
The mass of the helium will be 0.296 g He.
What is mass?
The quantity of matter in a thing is measured by its mass. Grams (g) or kilograms (kg) are the most common units of mass measurement (kg).The quantity of matter is measured in terms of mass, regardless of where it is in the universe or the gravitational force acting on it.
Calculation of mass of helium:
It is given that, atom of He = 4.50 X [tex]10^{22}[/tex] , mass of He = 4 g.
4.50 X [tex]10^{22}[/tex] atoms He × 1 mole He / 6.02 × [tex]10^{23}[/tex] atom He = 0.0914 mol He.
Now, apply the conversion formula:
Moles He × grams He / 1 mole He = grams He.
Put the value of given data in above formula.
0.0914 mol He × 4 g / 1 mol He = 0.296 g He.
Therefore, the mass of the helium will be 0.296 g He.
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I need help with this question...
identify a biological problem in your community and describe how you will use the scientific method to solve it
Answer:
There is a pawpaw here that is not producing any fruit.. so I will take a pollen grains from another pawpaw and pollinate it..
In order to prepare a sample for absorbance readings, a vitamin tablet containing 25 mg of iron was dissolved in 6M HCl, quantitatively transferred into a 100 mL volumetric flask and diluted to the 100 mL mark with DI water. Then 20 mL and 17 mL of this solution were pipetted into separate 100 mL volumetric flasks and each of these was brought up to 100 mL volume by diluting with DI water to the mark.
Required:
Calculate concentration of iron in mg/L in each of these flasks
Answer:
C₂ = 50 mg/L
C₃ = 42.5 mg/L
Explanation:
To do this, we just need to use the following expression:
C₁V₁ = C₂V₂ (1)
Where:
C₁: Original concentration of the Iron solution (mg/L)
V₁: aliquot of the iron solution (mL or L)
C₂: Concentration of the iron after beind dilluted (mg/L)
V₂: Volume of the flask that's being used.
Using the above expression, we just solve for C₂:
C₂ = C₁V₁ / V₂ (2)
We have the required volumes, but we do not have the concentration of the iron solution (C₁). To determine this, we use the initial flask of 100 mL and the mass of the iron:
C₁ = 25 mg / 0.1 L = 250 mg/L
With this value, we can replace in (2) to get the concentration on each flask.
Flask 1:
We have an aliquot of 20 mL, and it was dilluted to 100 mL, the concentration would be:
C₂ = 250 mg/L * (20/100)
C₂ = 50 mg/LFlask 2:
We have an aliquot of 17 mL dilluted to 100 mL so:
C₃ = 250 * (17/100)
C₃ = 42.5 mg/LHope this helps
The concentration of iron in mg/L in each of the two flasks is 50 mg/l and 42.5 mg/L respectively.
The initial concentration of iron in the sample is obtained as follows:
A vitamin tablet containing 25 mg of iron is dissolved in 6M HCl and then made up to 100 mL in a 100 mL volumetric flask with DI water.
Concentration of iron in the solution = 25 mg/ 100 mL
Converting to mg/L; 1 L = 1000 mL, then 100 mL = 1000 * 1 L/ 1000 mL = 0.1 L
Concentration of iron in the solution in mg/L = 25 mg / 0.1 L = 250 mg/L
Then 20 mL and 17 mL of this solution were pipetted into separate 100 mL volumetric flasks and each of these was brought up to 100 mL volume by diluting with DI water to the mark.
Using the dilution formula C₁V₁ = C₂V₂ to determine the concentration of iron in each of these flasks:
C₁ = initial concentration; V₁ = initial volume
C₂ = final concentration; V₂ = final volume
Flask 1:
C₁ = 250 mg/L, V₁ = 20 mL, C₂ = ?, V₂ = 100 mL
C₂ = C₁V₁ / V₂
C₂ = 250 * 20 / 100
C₂ = 50 mg/L
Flask 2:
C₁ = 250 mg/L, V₁ = 17 mL, C₂ = ?, V₂ = 100 mL
C₂ = C₁V₁ / V₂
C₂ = 250 * 17 / 100
C₂ = 42.5 mg/L
Therefore, the concentration of iron in mg/L in each of the two flasks is 50 mg/l and 42.5 mg/L respectively.
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Pls help I need a good grade
Answer:
Option 2
Explanation:
Which fuels are non-renewable
Answer:
fossil fuels
Explanation:
Well I had some topics on this stuff last quarter in science and from what I can remember it should be fossil fuels I think that fossil fuels are technically renewable but they are considered non-renewable since they are either in small supplies, are hard to obtain or take a long time to form.
How many grams are in 4.2 × 10²² atoms of iron?
Answer:0.226 gram
Explanation:you can get the answer in two steps calculate 3.40 . 10^22 atoms =
Answer:
4.2 × 10²² ÷ 6.022× 10²³
4.2 × 10²² equals 0.069 moles (approx)
weight of 1 mole of iron = 56g
therefore, 0.069 moles = 56 × 0.069 = 3.9 g
Sorry for lazy work.. :P
Nitrogen is important for _____. plant growth weather and temperature animals to breathe photosynthesis
Answer:
building amino acids in proteins
Explanation:
How is beryllium (Be) similar to calcium (Ca)?
Explanation:
beryllium, calcium, strontium, barium, and radium; they are in the same group of table.
Answer:
Both Beryllium and Calcium have 2 valence electrons, i.e. in ther electronic configuration there are 2 electrons remaining in the outermost shell. Thus their valencies are also 2.
Electronic Configurations:
Beryllium (4) : - [2, 2]
Calcium (20) : [2, 8, 8, 2]
Hope it helps
Thank you for the question
--------------------------------------------------------------------------------------------------------------
Edit
a. both are very reactive
b. both react readily with elements in group 1
c. both rarely combine with other elements
d. both are rare metals
(As per the suggestion of bvbfanforeverap5j54d)
During a laboratory experiment, 46.54 grams of Al2O3 was formed when O2 reacted with aluminum metal at 300.0 K and 1.2 atm. What was the volume of O2 used during the experiment?
3O2 + 4Al → 2Al2O3
a
12.51 liters
b
11.67 liters
c
10.19 liters
d
13.96 liters
Please help, Thanks
Answer:
13.96
Explanation:
sorry, too lazy to give the explanation, hopefully someone else will come along and give the proper explanation
Answer: 13.96 liters
How many moles of gas are present if P=1atm, V=1L, T=1K?
it depends on the chemical's molar mass
O.12
8.314
01
The number of moles of the ideal gas is 0.12 moles. Option A
What is the number of moles?In the context of the problem that we have here, we are looking at the ideal gas equation. When we look at the idea gas equation, we can tell that we would have the pressure of the gas, the volume of the gas as well as the temperature of the gas in view as is the case that we have here.
Thus, the idea that we are asked to pass across in the question is that we should be able to find out the number of moles that we have in the compound that have the variables that have been listed here.
Pressure (P) = 1 atm
Volume (V) = 1 L
Temperature (T) = 1 K
Number of moles (n) = ?
Using;
PV = nRT
n = PV/RT
n = 1 * 1/0.082 * 1
n = 0.12 moles
The moles of the gas is 0.12 moles.
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why is it important for a consumer to know the properties of a textile fibre
A thorough understanding of clothing and textiles will enable one to evaluate standards and product brands intelligently. It will also help one develop the capacity to recognize fabric quality, which will help one understand the best applications for the various qualities.
Understanding why some fabrics are more durable and so more suited for particular uses comes from studying textiles. It permits one to comprehend the rationale behind why particular materials generate cool-looking clothing in addition to creating the sense of coolness when used as décor. A thorough understanding of clothing and textiles will enable one to evaluate standards and product brands intelligently.
It will also help one develop the capacity to recognize fabric quality, which will help one understand the best applications for the various qualities. Although clothes don't necessarily make a person, they certainly help to develop a positive personality and a sense of self-assurance. Housewives should therefore be familiar with clothing and textiles to obtain the best out of it.
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The half-life of Po-218 is three minutes. How much of a 2.0 gram sample remains after 15 minutes? Suppose you wanted to buy some of this isotope, and it required half an hour for it reach you. How much should you order if you need to use 0.10 gram of this material?
(2)(½^(15/3)) = 0.0625 (5 half-lives) 102.4 grams order
What is the half-life of an isotope?A radionuclide's half-life is the amount of time it takes for half of its radioactive atoms to decay. A good rule of thumb is that you will have less radiation than 1% of the original amount after seven half-lives.Knowing an element's alpha, beta, or gamma decay can help someone properly protect their body from excessive radiation. Within one half-life, the amount of radioactive nuclei present at any particular time will be reduced to half.Each radioisotope has a set half-life that can be anywhere between a few milliseconds (for example, 215At at 0.1 milliseconds) and billions of years (e.g.,238U at 4.468 billion years). Both stable and radioactive isotopes can exist for an element.The period of time needed for something to go from 50% to 50%To learn more about half-life of an isotope refers to:
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8KCIO3 +1C12H22011
- >12CO2 + 11H20 + 8KCI
If you want the gummy bear to be the limiting reactant
for the reaction above, what is the minimum
amount of potassium chlorate that must be used to react completely with one gummy bear?
note: gummy bears are many made up of sucrose (1.1 g of sucrose in this equation)
3.2 g KClO3
Explanation:
1.1 g C12H22O11 × (1 mol C12H22O11/342.3 g C12H22O11)
= 0.0032 mol C12H22O11
0.0032 mol C12H22O11 × (8 mol KClO3/1 mol C12H22O11)
= 0.026 mol KClO3
Therefore, the minimum amount of KClO3 needed is
0.026 mol KClO3 × (122.55 g KClO3/1 mol KClO3)
= 3.2 g KClO3
The molar solubility of calcium sulfide in a 0.222 M sodium sulfide solution is:________-
Rocky objects that are massive enough will have a spherical shape due to the force of gravity. (no links or else I will report you)
True
False
explain how dna which is 6 feet long, can be stored in the nucleus of a tiny human cell.
Answer:
Packed inside the nucleus of every human cell are nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1.5 inches long. Packing all this material into a microscopic cell nucleus is an extraordinary feat of packaging.
Explanation:
Packed inside the nucleus of every human cell are nearly 6 feet of DNA, which is divided into 46 individual molecules, one for each chromosome and each about 1.5 inches long. Packing all this material into a microscopic cell nucleus is an extraordinary feat of packaging. For DNA to function, it can't be crammed into the nucleus like a ball of string. Instead, it is combined with proteins and organized into a precise, compact structure, a dense string-like fiber called chromatin.
(hope this helps can i plz have brainlist :D hehe)
12. Surface lakes of glacier meltwater are shown overflowing into channels, which then pour down
moulins. What happens to this water? Why is this bad for the glacier?
When surface lakes of glacier meltwater overflow into channels and pour down moulins (vertical shafts or tunnels in the ice), the water typically flows into the base of the glacier and can cause the glacier to melt more rapidly. This process is known as "moulin drainage," and it can be detrimental to the glacier because it can cause the glacier to lose mass more quickly.
Losing mass through moulin drainage can cause a glacier to retreat or shrink in size, which can have a number of impacts on the surrounding environment. For example, if a glacier is a primary source of water for a region, its retreat could lead to water shortages. In addition, the loss of a glacier can affect the local ecosystem and wildlife, and it can contribute to sea level rise if the glacier is located near the coast.
HOPE IT HELPS!The Law of Conservation of Matter states that in a closed system, matter cannot be created or destroyed. This means that atoms can NOT just appear or disappear. The mass will not change in a closed system.
This, however, is NOT what we observed. We observed that the mass of the substance in our measuring tray increased after burning.
Why do you think this happened? Where did the extra mass come from?
REMEMBER: Energy (light, heat, motion, etc.) is not made of atoms so has no mass.
RESOURCE: Access your online textbook through CLEVER, click to get the blue ribbon across the top of the page and go to the Table of Contents. Scroll down to Lesson 9 Conservation of Matter and select "Extending Your Knowledge: Mass and Matter"
Answer:
The Law of Conservation of Matter states that in a chemical reaction, matter is not created or destroyed. However, it is possible for the mass of a substance to change during a chemical reaction, as you observed.
When a substance burns, it reacts with oxygen in the air to form new compounds. For example, when wood burns, it reacts with oxygen to form water and carbon dioxide. The mass of the wood plus the mass of the oxygen is equal to the mass of the water and carbon dioxide produced.
In this case, the extra mass that you observed came from the oxygen that reacted with the wood. Oxygen has mass, and when it reacts with the wood, the mass of the resulting compounds is greater than the mass of the starting materials.
It's important to note that energy is not a form of matter, and therefore has no mass. However, energy can be converted into matter and vice versa, according to the famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light. This equation demonstrates that mass and energy are fundamentally connected and can be converted into each other under certain conditions.
Explanation:
PLEASE HELPPP ME
Use the following balanced chemcial equation to answer the question below.
CaBr2 + Na2SO4 --> CaSO4 + 2NaBr
1. How many moles of sodium bromide can be made from 5 moles of calcium bromide
2. How many grams of calcium sulfate will be made from 2.00 moles of calcium bromide
3. How many grams of calcium bromide will be needed to make 845 grams of calcium sulfate
Answer:
1) (5 moles of calcium bromide) x 2 / 1 = 10 moles
2) (2.00 moles of calcium bromide) = 2.00 moles of calcium sulfate
so (2.00) x (136.1 g/mol) = 272.2 g
3) (845 grams of calcium sulfate) / 136.14 g/mol = 6.21 moles
6.21 moles of calcium sulfate = 6.21 moles of calcium bromide
(6.21 moles of calcium bromide) x 199.89 g/mol = 1241.32 g
How many atoms of oxygen are included in one glucose molecule?
Answer:
6 atoms of oxygen are included.
Explanation:
Saw a similar answer
Also
Have a great day :D
Answer:
6 atoms are included :)
Explanation:
1 molecule of glucose contains 6 atoms
What do the observations for changes to volume and pressure show you about the
relationship between the volume and pressure of a gas? Explain using the data! Does
this demonstration support Boyle's Law or not?
(Hint: pressure is not being measured in this video, but think what would happen to a
balloon if it was squeezed or compressed. Would it get larger or smaller?)
Answer: The given demonstration does not support Boyle's Law.
Explanation:
According to Boyle's law, at constant temperature the pressure of an ideal gas is inversely proportional to the volume of gas.
[tex]P \propto \frac{1}{V}[/tex]
Therefore, an increase in volume of gas will lead to a decrease in pressure and vice-versa.
Now, according to the given data of volumes there is occurring an increase on moving from final volume 1 to final volume 3. This means that pressure is decreasing.
As a result, if a balloon was squeezed or compressed then it would get smaller. But in the given demonstration pressure is not given.
Thus, we can conclude that the given demonstration does not support Boyle's Law.
Which of the following is an oxidation-reduction reaction?
A) HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)
B) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)
C) Pb(C2H3O2)2(aq) + 2 LiBr(aq) → PbBr2(s) + 2 LiC2H3O2(aq)
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)
E) All of the above are oxidation-reduction reactions.
Answer:
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)
Explanation:
In a redox reaction, One atom is gaining electrons (Reduction) whereas other is loosing electrons (Oxidation). In the reactions:
A) HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)
As sodium is always +1 and Br always -1, this is not a redox reaction.
B) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)
Sodium is always +1 and nitrate ion is -1. This is not a redox reaction
C) Pb(C2H3O2)2(aq) + 2 LiBr(aq) → PbBr2(s) + 2 LiC2H3O2(aq)
Acetate ion, C2H3O2 is -1 as Br is -1, lithium is +1 and Pb +2, This is not a redox reactoin
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)Barium is 0 as Ba(s) but +1 as BaCl2. Is oxidizing
Hydrogen is +1 as HCl but 0 as H2. Is reducting.
This reaction is an oxidation-reduction reaction
The Millikan oil-drop experiment, which was the first experiment to measure the charge of the electron, compared the electrical force on a small charged oil drop with the force exerted on this drop by gravity.
a. True
b. False
Answer:
True
Explanation:
The oil drop experiment was carried out by Robert Millikan and Harvey Fletcher in 1909 to determine the charge of an electron. By balancing downward gravitation force with upward drag and electric force, they suspended small charged droplets of oil between two metal electrodes.
The charge over an oil droplet was often an integral value of e, was determined by changing the intensity of the electric field.
So, the given statement is true
HELP ME PLS
type an actual answer insted of saying I will help you
Answer:
develops,blossoms are synonyms
Balance the following chemical equation:
Br2+
Nal-
NaBr
+
Answer:
2 NaI (aq) + Br2 (aq) → 2 NaBr (aq) + I2 (s)
This is an oxidation-reduction (redox) reaction:
2 Br0 + 2 e- → 2 Br-I
(reduction)
2 I-I - 2 e- → 2 I0
(oxidation)
What are the similarities and differences between ionic and covalent bonds?
Which of the following best describes radiation? A. A specific wavelength of energy that can be natural or man-made. B. Particles or waves emitted from an atom. C. Dangerous energy emitted from man-made nuclear power sources. D. The unstable nucleus of an atom.
Answer:
c. just like in xray machines
Explanation:
Radiation is the energy that contains electric and magnetic fields. They are the particles or the waves that are emitted from the atom. Thus, option B is correct.
What are radiations?Radiations are the energy or the waves transmitted in a medium or space due to the excitement of the atomic electronic transition. They are caused due to emission and removal of the electron from the atom's inner shell.
They are used in various fields of science including health and medicine where they are used to treat cancerous and tumor cells by killing the abnormal cells or slowing their growth.
Also, they are harmful as they act as mutagens that can alter the genetic material of the organism and can posses a dangerous threat to health.
Therefore, radiations are the waves emitted from atoms.
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Plz help ASAP
What is the molarity of a 0.6 L solution that contains 50.0 grams of sodium hydroxide(NaOH)?
A) 2.1 M
B) 2.9 M
C) 3.3 M
Answer: A 2.1
Explanation:
the maximum allowed concentrations of chloride in municipal drinking water supply in 250 ppm cl. when the supply of water exceeds this limit it often has a distinctive salty taste. what is the concentration in molarity?
The allowed concentration of Cl in water is 250 ppm. Then the equivalent concentration in molarity is 0.007 molar.
What is molarity ?Molarity is a common term used to express the concentration of a solution. It is the ratio of the number of moles of solute to the volume of solution in liters. Molarity is a temperature dependent measurement.
Parts per million is another term of concentration have the formula as written below:
ppm = ws/W × 10⁶
Where, ws is the weight of solute and W be the weight of solution in grams.
1 molar = 35500 ppm
therefore, 250 ppm = 250 ppm × 1M /35500 ppm = 0.007 M.
Hence, the molarity of the salt solution will with the maximum allowed concentration will be 0.007 M.
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Write a skeleton molecular equation for the following chemical reaction: Sulfuric acid reacts with solid sulfur to form sulfur dioxide gas and water. You should have two equations, one word equation and one chemical equation.
Word equation: sulfuric acid + sulfur -> sulfur dioxide + water
Chemical equation: H2SO4 + S -> SO2 + H2O
Answer:
Word equation: Sulfuric acid + Sulfur → Sulfur Dioxide + Water
Chemical equation: H2SO4 + S → SO2 + H2O
Explanation: