Answer:
I think the body system
Explanation:
Answer:body system
Explanation:
The pH of an acidic solution is 2.11. What is [H⁺]
Answer:
7.76 x 10^-3 M
Explanation:
pH = -log(x)
2.11 = -log (x)
10^-2.11 = 7.76x10^-3 M
Considering the definition of pH, the concentration [H⁺] is 7.76×10⁻³ M
You need to know that pH is the Hydrogen Potential. It is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
Mathematically, pH is calculated as the negative base 10 logarithm of the activity of hydrogen ions:
pH= - log [H⁺]
The numerical scale that measures the pH of substances includes the numbers from 0 to 14. The pH value 7 corresponds to neutral substances. Acidic substances are those with a pH lower than 7, while basic substances have a pH higher than 7.
In this case, being pH= 2.11, you can replace this value in the definition of pH:
2.11= -log [H⁺]
Solving:
[H⁺]= 10⁻² ¹¹ M
[H⁺]= 7.76×10⁻³ M
Finally, the concentration [H⁺] is 7.76×10⁻³ M
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3. How many times does earth rotate on its axis in one year?
Answer:
There are approximately 366.25 sidereal days in a year so that the Earth spins 366.25 times with respect to distant stars in a year
hope this helps
have a good day :)
Explanation:
Please someone answer this asap
Answer:
b or c but I would just pick c
Answer:
C
Explanation:
Sun is an energy source not a matter.
Which of the following is a characteristic shared by all living things?
A. They have tissues and organs,
B. They take in oxygen.
C. They make more individuals of the same kind.
D. They move.
Limestone has a density of 2.72 g/cm3. What is the mass of 8.92 cm3 of limestone?
Answer:
[tex]\boxed {\boxed {\sf 24.2624 \ g}}}[/tex]
Explanation:
Density measures mass per volume. The volume is
[tex]\rho=\frac{m}{v}[/tex]
The density of limestone is 2.72 grams per cubic centimeter. We have a piece of limestone with a volume of 8.92 cubic centimeters.
ρ= 2.72 g/cm³v= 8.92 cm₃Substitute the values into the formula.
[tex]2.72 \ g/cm^3=\frac{m}{8.92 \ cm^3}[/tex]
Now we solve for m, the mass, by isolating the variable.
m is being divided by 8.92 cubic centimeters. The inverse of division is multiplication, so we multiply both sides by 8.92 cubic centimeters.
[tex]8.92 \ cm^3 * 2.72 \ g/cm^3=\frac{m}{8.92 \ cm^3}* 8.92 \ cm^2[/tex]
[tex]8.92 \ cm^3 * 2.72 \ g/cm^3=m[/tex]
The units of cubic centimeters cancel out.
[tex]24.2624 \ g =m[/tex]
The mass of this piece of limestone is 24.2624 grams.
131.39 g/mol C2HCl3
find the molecular formulas
Answer:
Find the mass of 1 mole.
mass of
1
mole of
131.39
g
m
o
l
C
2
H
C
I
⋅
3
=
37.04000067
g
Explanation:
hope it helps make brainlliest ty
7.In the oxidation of ethane: 2 C2H6 + 7 02 + 4CO2 + 6H2O how many
liters of O2 are required to react with 90 grams of ethane?
Answer:
If reaction is taking place at room temperature and pressure(rtp)
= 360 litres of O₂ at rtp
If reaction is taking place at standard temperature and pressure(stp):
= 336 litres of O₂ at stp
Explanation:
2C₂H₆ + 70₂ → 4CO₂ + 6H₂O
1 mole of C₂H₆ = (12 × 2) + (1 × 6) = 24 + 6 = 30g
2 moles of C₂H₆ = 30 × 2 = 60g
From the equation:
1 mole of 0₂ reacts with 2 moles of C₂H₆
1 mole of 0₂ reacts with 60g of C₂H₆
? moles of 0₂ react with 90g of C₂H₆
[tex]\frac{90}{60}[/tex]= 1.5 moles of O₂
Considering condition of reaction taking place whether room temperature and pressure(rtp) or standard temperature and pressure(stp)
If room temperature and pressure(rtp):
1 mole of 0₂ occupies 24 liters/24000 cm³/ 24 dm³ of O₂
1.5 moles of O₂ occupies (24 × 1.5) litres of O₂
= 360 litres of O₂ at rtp
If standard temperature and pressure(stp):
1 mole of 0₂ occupies 22.4 liters/22400 cm³/ 22.4 dm³ of O₂
1.5 moles of O₂ occupies (22,4 × 1.5) litres of O₂
= 336 litres of O₂ at stp
Thorium-236 has a half life of 10.0 minutes.If I have 250 grams of Thorium-236 , how many half lives will have taken place after 50.0 minutes?
Answer:
5 half lives
Explanation:
Given that
Thorium - 236 contains the half-life of 10.0 minutes
And there is 250 grams
We need to find out the number of half lives that took place after 50.0 minutes
As in the question
1 half life is 10 minutes
So for 50 minutes, it would be
= 50 minutes × 1 half life ÷ 10 minutes
= 5 half lives
what would be the observation when pineapple juice is dipped in a red litmus paper
Answer:
red litmus paper change into blue when it is dipped into Pineapple juice.
hope it helps
The red litmus paper will stay red when dipped in pineapple juice.
What are acids and bases?Acids are substances that can donate a proton to another substance. A base is a substance that can accept a hydrogen ion from an acid.
Acidic substances are often characterized by their sour taste. An acid commonly can be energetically favorable after a loss of H⁺ ion and is also known to turn blue litmus paper into red.
Bases are generally recognized for their bitter taste and slippery texture. A base that can dissolve in water is also referred to as alkali and is also known to turn red litmus paper into blue.
The pH value of the pineapple juice lies between 2.5 to 3.9. Therefore, it is acidic in nature as the pH of acidic substances lies in the range of 0 to 7. So the red litmus paper will stay red in pineapple juice.
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When elemental sodium reacts with water, sodium hydroxide and hydrogen will form. What mass of sodium (in grams) must be reacted with excess water to produce 325 mL of hydrogen gas at 25.0oC and 1.15 atm?
Answer:
0.703g Na must reacted
Explanation:
The reaction of Sodium, Na, With water, H₂O is:
2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)
Where 2 moles of sodium reacts with an excess of water to produce 1 mole of hydrogen
To solve this question we have to use PV = nTR to solve the moles of the gas. With the moles of hydrogen we can find the moles of sodium that reacted and its mass:
Moles H₂:
PV = nRT
PV /RT = n
Where P is pressure = 1.15atm
V is volume in liters = 0.325L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 25°C + 273 = 298.0K
1.15atm*0.325L / 0.082atmL/molK*298.0K = n
0.0153 moles of hydrogen are produced
Moles Na:
0.0153 moles H₂ * (2moles Na / 1mol H₂) = 0.0306 moles Na
Mass Na -Molar mass: 22.99g/mol-:
0.0306 moles Na * (22.99g / mol) =
0.703g Na must reactedA student thermally decomposed a 0.150 gram sample of impure potassium chlorate. Manganese dioxide was used as a catalyst in the reaction. The student collected 43.60 mL of oxygen gas over water in a eudiometer. Potassium chloride was the other product of the reaction. The temperature and pressure at collection time were 20.00 oC and 762.10 mm Hg respectively. The water level in the eudiometer was 4.22 cm below the outside water level in the beaker.
1) What is the corrected pressure of the dry oxygen gas?
2) What is the volume in mL, of the dry oxygen gas at STP conditions?
3) How many molecules of oxygen were collected?
4) what is the percent purity of the original potassium chlorate sample?
Answer:
1. Vapor pressure of dry oxygen gas = 747.68 torr
2. Volume at STP = 39.97 mL
3. Number of oxygen gas molecules = 1.074 × 10²¹ molecules
4. Percent purity of KClO3 = 97.3 %
Explanation:
The balanced equation for the reaction is given below :
2 KClO3 (s) ------> 2 KCl (s) + 3 O2 (g)
1) Since the water level in the eudiometer was below the outside water level in the beaker,
Vapor pressure of dry oxygen gas = Total pressure + pressure due to difference in water levels - vapor pressure of water
Vapor pressure of water at 20 °C is 17.535 mm (torr).
Pressure due to difference in water level = 4.22 cm × 10mm/cm / 13.534 (13.534 is the density of mercury) = 3.118 mm (torr).
Vapor pressure of dry oxygen gas = 762.10 torr + 3.118 torr - 17.535 torr
Vapor pressure of dry oxygen gas = 747.68 torr
2) P₁ = 747.68 torr; V₁ = 43.60 ml; T1 = 20 °C + 273.15 = 293.15 K
P₂ = 760 torr; T₂ = 273.15 K; V₂ = ?
Using the general gas equation = P₁V₁/T₁ = P₂V₂/T₂
V2₂= P₁V₁T₂ / P₂T₁
V₂ = (747.68 × 43.60 × 273.15 ) / (760 × 293.15)
V₂ = 39.97 ml
Volume of dry oxygen gas at STP = 39.97 mL
3) Volume of oxygen gas at STP 39.97 mL = 0.03997 L
Number of moles of oxygen gas in 0.03997 L = volume of gas at STP /molarvolume at STP
Number of moles of oxygen gas = 0.03997/22.4 L
Number of molecules of oxygen gas = 0.03997/22.4 L × 6.03 × 10²³ molecules
Number of oxygen gas molecules = 1.074 × 10²¹ molecules
e) Number of moles of oxygen gas = 0.03997/22.4 = 0.001784 moles
From the equation, mole ratio of oxygen gas and potassium chlorate is 3 : 2
Moles KClO3 = 2/3 × 0.001784 moles = 0.001189 moles
Molar mass of KClO3 = 39 + 35.5 + 3 × 16 = 122.5 g
Actual mass of KClO3 decomposed = 122.5 grams × 0.001189 mole = 0.146 grams
Percent purity = (actual mass KClO3 decomposed / sample mass of impure KClO3) × 100%
Percent purity = (0.146/0.150) × 100% = 97.3 %
2 Which of the gases in air are elements? Explain how you can tell.
Answer:
I'll explain.
Explanation:
The molecules of two different elements, nitrogen and oxygen, make up about 99 percent of the air. The rest includes small amounts of argon and carbon dioxide. Oxygen is the life-giving element in the air. You can tell because they're on the periodic table which is a table for elements.
Explanation:
nitrogen and oxygen are the gases in the air which are elements you can simply say it by looking the periodic table
Write a balanced equation for the double-replacement precipitation reaction described, using the smallest possible integer coefficients. A precipitate forms when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. Do not include states such as (s) or (aq). It is not necessary for you to indicate which of the products is the precipitate.
Answer:
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
Explanation:
Let's consider the unbalanced equation for the reaction that occurs when aqueous solutions of nickel(II) nitrate and sodium carbonate are combined. This is a double-replacement precipitation reaction.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + NaNO₃
We will balance the equation using the trial and error method.
First, we will balance Na atoms by multiplying NaNO₃ by 2.
Ni(NO₃)₂ + Na₂CO₃ ⇒ NiCO₃ + 2 NaNO₃
As we can see, the equation is balanced.
What is the energy of a photon?
A. A photon has no energy.
B. The energy of a photon is hxc.
c. The energy of a photon is hx 2.
D. The energy of a photon is h* f.
Laughing gas can decompose into nitrogen and oxygen
Nitrous oxide decomposes into nitrogen and oxygen, according to 2 N2O (g) -> 2 N2 (g) + O2 (g). ... In an experiment, a stream of N2O is passed through a tube 25 mm in diameter and 20 cm long. The flow rate of the gas is 0.75 L/min.
name the process which takes place when propene gas molecules are converted into a giant molecule
Answer:
Polymerization, any process in which relatively small molecules, called monomers, combine chemically to produce a very large chainlike or network molecule, called a polymer. The monomer molecules may be all alike, or they may represent two, three, or more different compounds.
A body system is a group of organs that work together to keep the organism
alive. How does the respiratory system help to keep an organism alive?
A. The respiratory system helps the organism respond to its
environment.
B. The respiratory system helps the organism absorb nutrients from
its environment.
O C. The respiratory system takes in oxygen and releases carbon
dioxide.
O D. The respiratory system carries oxygen to the organism's cells.
Answer:The lungs expel the carbon dioxide and bring in new oxygen-containing air. Only when both systems are working together can oxygen and carbon dioxide be successfully exchanged between cells and environment. There are many other examples of this cooperation in your body.
Explanation:
Hope it will help
Question:
A body system is a group of organs that work together to keep the organism
alive. How does the respiratory system help to keep an organism alive?
A. The respiratory system helps the organism respond to its
environment.
B. The respiratory system helps the organism absorb nutrients from
its environment.
O C. The respiratory system takes in oxygen and releases carbon
dioxide.
O D. The respiratory system carries oxygen to the organism's cells.
Answer:
O C. The respiratory system takes in oxygen and releases carbon
dioxide.
Explanation:
Breathing uses chemical and mechanical processes to bring oxygen to every cell of the body and to get rid of carbon dioxide. Our body needs oxygen to obtain energy to fuel all our living processes. Carbon dioxide is a waste product of that process
Hope This Helps?
I need the correct answers
Answer:
Acids: Tastes Sour
Has a ph less than 7
Base: Bitter
Has a ph greater than 7
slippery
Acid&Base: Conducts electricity
CH4 +2H2S = CS2+ 4H2
If the reaction shifts to the right what are the products?
If the reaction shifts to the right, which chemicals decrease in The process?
If the reaction shifts to the left what are the products?
If the reaction shifts to the left, which chemicals decrease in the process?
A___
is a
small, rocky object
that orbits the sun
and has broken
off from a comet
or asteroid.
(Fill in the blank)
Answer:
I think it is a rock...
Explanation:
maybe idrk tho
You tested the rocket with three mixtures of fuel having different masses of oxygen
and hydrogen. What is the relationship between the masses of oxygen and hydrogen in
each of the tests?
Answer:
As the oxygen is only transferred from the copper oxide to form water inside the apparatus, any gain in mass is due to hydrogen combined with the oxygen to form water. The ratio of the two masses enables the mass of oxygen combining with 1 g of hydrogen to be calculated.
Hydrogen and oxygen are the elements used as fuels in rockets as they are propellants. In each of the tests, the ratio of the mass of hydrogen to oxygen is 1:8.
What is the combustion of rocket fuel?Combustion has been the chemical reaction that involves reactants combining and reacting with oxygen resulting in heat and light formation. They are majorly used in propelling engines and in rocket fuels.
In a rocket engine oxygen acts as the oxidizer that reacts with hydrogen atoms to derive the heat and energy so that the engine can move and produce thrust. It uses Newton's third law to create energy and accelerate upwards.
The mixtures of fuel contain various masses that are present in a ratio of 1:8 (hydrogen: oxygen) as masses of hydrogen are 1, 2, and 5 mg, whereas oxygen is 8, 16, and 40 mg. It can be concluded that 1 part of hydrogen reacts with 8 parts of oxygen in the rocket fuel mixture.
Therefore, the rocket fuel mixtures contain a 1:8 ratio of the masses of hydrogen: oxygen that undergoes combustion reaction.
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The number of atoms in a 158.4 g sample of CO2 gas at STP is:
1.277 x 1025 atoms
2.167 x 1024 atoms
6.502 x 1024 atoms
6.651 x 1024 atoms
Answer:
Option B, 2.167 x 1024 atoms
Explanation:
1 mole of CO2 = 44.01 grams
Number of moles of CO2 in 158.4 gram sample
[tex]\frac{158.4}{44.01} \\3.95[/tex]moles
Number of atoms in one mole is [tex]6.02*10^{23}[/tex]
Number of atoms in 3.95 moles [tex]2.167 *10^{24}[/tex]
Hence, option B is correct
21. What are the individual ion
22. If the C2H302 ion concentration in a solution is 0.554 M, what is the concentration of
Ca(C2H2O2)2?
Answer:
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Explanation:
vugjb oh in luv ug ug yf fyi dxezw f f g gjhc ydzt
Approximately what percent of the landmass on earth receives
very little or no rainfall?
Answer:
the desert (33% of the worlds surface)
Explanation:
Most of the world's surface is covered in water, in the form of oceans. The remaining landmass of Earth amounts to approximately 29 per cent of the surface. Of this remaining 29 per cent, deserts of all types constitute an estimated 33 per cent, or one-third, of the Earth's total landmass.
What is the percentage of water to land on Earth?
In simplest terms, water makes up about 71% of the Earth's surface, while the other 29% consists of continents and islands.
Which percentage of the total area of the earth is covered by soil?Only about 7.5% of the Earth's surface provides the agricultural soil on which we depend for the world's food supply and this fragment competes, sometimes unsuccessfully, with all other needs: housing, cities, schools, hospitals, shopping centres, landfills, etc.
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of the two Lewis/electron dot
structure representations, which is
the correct one for oxygen gas?
The electron dot diagram for an element shows the valence electrons for the element. Oxygen is in group 16/VIA, so it has six valence electrons. Draw the symbol for oxygen. Then place one dot at each side of the symbol.
20 grams of hydrogen fluoride gas, HF, is dissolved in 0.5 liters of solution. Determine the molarity (M).
Answer:
40
Explanation:
M = n/v hope this helps :b
Determine the number of electrons in an Cl ion with a charge of -3
Answer:
There are 20 electrons.
Explanation:
Chlorine has 17 electrons in its atom to begin with (you can tell from the proton number in the periodic table).
A charge of -3 means that the chlorine atom gained 3 electrons, and now needs to lose 3 electrons to return to its atom configuration.
What is the total number of Joules lost when 10. grams of water at 80.°C is cooled to 60.°C?
Answer:
[tex]\boxed {\boxed {\sf 836.8 \ Joules \ lost}}[/tex]
Explanation:
Since we are given the mass and change in temperature, we should use the following formula for heat.
[tex]q= mc \Delta T[/tex]
In this formula, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
We know the mass of the water is 10 grams. We will have to look up water's specific heat, because it is not given. It is 4.184 J/g °C.
Let's find the change in temperature. This is the difference of the final and initial temperature. The water started at 80 °C and cooled to 60°C.
ΔT= final temperature - initial temperature ΔT= 60° C - 80°C ΔT= -20 °CNow we have values for each variable.
m= 10 gc= 4.184 J/g°C ΔT= -20°CSubstitute the values into the formula.
[tex]q= 10 \ g * 4.184 \ J/g \textdegree C * -20 \textdegree C[/tex]
Multiply the first 2 numbers. The units of grams will cancel each other out.
[tex]q= 41.84 \ J/ \textdegree C * -20 \textdegree C[/tex]
Multiply again. This time, the degrees Celsius cancel.
[tex]q= -836.8 \ J[/tex]
A total of 836.8 Joules are lost.
A solution generally consists of two parts, a solute that is dissolved and a solvent that the solute is dissolved into. For example, sugar is a solute that is dissolved into the solvent water. In the Solubility and Temperature Gizmo, you will study how temperature affects how much solute will dissolve in a solution. To begin, check that Potassium nitrate is selected and the Temp. of the water is 20 °C. Click OK. In this solution, what is the solute? What is the solvent?
Answer:
Solute is Pottasium Nitrate and Solvent is Water.
Explanation:
Name the part in red:
H2 + O2 -> H2O
Answer:subscript
Explanation: