Answer: chemical change
what mass of O2(g) is required to completely react with 25.0g of Fe(s)?
3Fe(s) + 2O2(g) → Fe3O4(s) (Balanced)
What is the volume of 3.00 M sulfuric aid that contain 9.809 g of H2SO4 (98.09g/mol)
Given :
Molarity of sulfuric acid solution is 3.0 M.
Amount of sulfuric acid present in solution is 9.809 g.
To Find :
The volume of solution.
Solution :
We know, molarity is given by :
[tex]Molarity = \dfrac{number \ of \ moles \times 1000}{Volume\ ( ml )}\\\\M = \dfrac{w \times 1000}{M.M \times V}\\\\3 = \dfrac{9.809\times 1000}{98.09 \times V}\\\\V = \dfrac{1000}{10\times 3}\ ml\\\\V = 33.33 \ ml[/tex]
Therefore, volume required is 33.33 ml .
Are all antigens foreign substances?
No, not all antigens are foreign substances.
An antigen is any substance that can trigger an immune response, including the production of antibodies. Some antigens are naturally present in the body and are called "self" antigens which are usually not harmful, but in some cases, the immune system can mistakenly recognize them as foreign and attack them which can lead to autoimmune diseases.
Antigens bind together with antibodies and promote the elimination of harmful pathogens present in the body. They alert other parts of the immune system to take over which helps to neutralize the threat from pathogens.
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How many Liters of a 4.5 M HCL solution can be prepared by using 250.0 mL of a 12.0 M HCl solution?
Answer:
0.667 L
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 250 mL
Initial concentration (C₁) = 12 M
Final concentration (C₂) = 4.5 M
Final volume (V₂) =?
The final volume of the solution can be obtained by using the dilution formula as illustrated below:
C₁V₁ = C₂V₂
12 × 250 = 4.5 × V₂
3000 = 4.5 × V₂
Divide both side by 4.5
V₂ = 3000 / 4.5
V₂ = 667 mL
Finally, we shall convert 667 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
667 mL = 667 mL × 1 L / 1000 mL
667 mL = 0.667 L
Thus, the volume of the solution prepared is 0.667 L
How does a fire help grasslands? Choose all that apply
Question 5 options:
keeps trees from overtaking the grasses
preserve biodiversity
helps contain only coarse grass
all of the above
Answer:
I believe its all above
Explanation:
Fire on grasslands keep the tress from overtaking the grasses on fire. They can thereby preserve biodiversity. Fire on grassland helps contains coarse grass only. Therefore, all of the above is correct.
What are the impacts of fire on grasslands?The addition of nutrients to the soil, the facilitation of easier grazing by herd animals, and the inhibition of the establishment of invasive plant species all contribute to the health and sustainability of grasslands.
The grassland ecology benefits from the natural occurrence of fire since it keeps it strong and healthy. It increases the soil's temperature and lessens the annual buildup of leaf litter, allowing sunshine to enter.
Warming the soil stimulates microbial activity, which liberates nutrients from decomposing plant matter that are essential for the growth of new grasses and flowers. All the given points are in direct or indirect way help the grassland.
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What is atomic radius?
Answer:
The atomic radius of a chemical element is the measure of the size of its atoms, usually the mean or typical distance from the centre of the nucleus to the boundary of surrounding shells of electrons
Hope it helps :)
Pick the selection that increases in energy.
7f, 6s, 4p
4s, 4p, 4d
1s, 6f, 4d
3d, 4s, 3p
Answer:
i think mix im um 1s 6f 4d is correct answer
Which statement is correct about the rate of a chemical reaction? (5 points)
a. It increases when the concentration of reactants increases.
b. It does not depend on the concentration of reactants.
c. It increases when the temperature decreases.
: d. It does not depend on the temperature.
Answer:
they don't depend on the temperature
You pour some hot water into a metal cup. After a minute,
you notice that the handle of the cup has become hot.
Explain, using your knowledge of heat transfer, why the
handle of the cup heats up. How would you design the cup so
that the handle does not heat up?
Heat transfer is the movement of thermal energy from a temperature that is higher to one that is lower.
Thermoenergy: What is it?The energy that exists in a system and controls its temperature is known as thermal energy. Heat is thermal energy in motion. Thermodynamics is a comprehensive field of physics that examines how heat and work are transferred between diverse systems.
Energy of what kind is thermal energy?The energy that results from atoms and molecules moving around within a substance is known as thermal energy, often known as heat. When these particles move more quickly, heat is produced. Geothermal energy is the earth's heat energy. Energy held within motion is referred to as motion energy.
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Today we are going to perform a titration. What is an acid-alkali titration?
a) A measurement apparatus
b) An analytic method
c) A chemical reaction
LABSTER
Answer:
A chemical reaction
Explanation:
You're doing acid-alkali. Acid is like a ph.
Titration is a method used to prepare salts if the reactants are soluble. Concentration and volumes of reactants can be calculated from titrations. The concentration of an acid or alkali can be calculated by carrying out an experiment called a titration.
We have that for the Question "Today we are going to perform a titration. What is an acid-alkali titration?" it can be said that
From the question we are told
Today we are going to perform a titration. What is an acid-alkali titration?
a) A measurement apparatus
b) An analytic method
c) A chemical reaction
Generally
acid-alkali titration is a popular chemical reaction that is used to obtain salts and this method is also used to determine many other variables of the reactants
Therefore
An acid-alkali titration is a
chemical reaction
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What mass of O2 molecules contains the same number of oxygen atoms as 14.0 g of water?
Answer:
So 0.39 moles of oxygen are produced in 14 g of water. So that's it.
Explanation:
Why do some elements not take part in chemical bonds?
Answer:
Because there is some element which is already in an octet state and has no need to achieve it, they have a full electron in their outermost shells such as helium, argon etc.
If 0.034 moles of potassium nitrate were formed how many moles of lead (II) nitrate did you start
with?
Answer:
0.017 mole of Pb(NO₃)₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2KOH + Pb(NO₃)₂ —> 2KNO₃ + Pb(OH)₂
From the balanced equation above,
1 mole of Pb(NO₃)₂ reacted to produce 2 moles of KNO₃.
Finally, we shall determine the number of mole of Pb(NO₃)₂ required to produce 0.034 mole of KNO₃. This can be obtained as follow:
From the balanced equation above,
1 mole of Pb(NO₃)₂ reacted to produce 2 moles of KNO₃.
Therefore, Xmol of Pb(NO₃)₂ will react to produce 0.034 mole of KNO₃ i.e
Xmol of Pb(NO₃)₂ = 0.034 / 2
Xmol of Pb(NO₃)₂ = 0.017 mole.
Thus, 0.017 mole of Pb(NO₃)₂ is needed for the reaction.
A 2.5 L container is filled with propane. The ambient temperature is 25°C and the
pressure in the container is about 3 atmospheres. If the temperature in the car
reaches 55°C (about 130°F), what will be the pressure in the container?
Answer:
The pressure inside the container will be 3.3 atmospheres
Explanation:
The relationship between the temperature and pressure of a gas occupying a fixed volume is given by Gay-Lussac's law which states that the pressure of a given amount of gas is directly proportional to its temperature on the kelvin scale when the volume is kept constant.
Mathematically, it expressed as: P₁/T₁ = P₂/T₂
where P₁ is initial pressure, T₁ is initial temperature, P₂ is final pressure, T₂ is final temperature.
The above expression shows that the ratio of the pressure and temperature is always constant.
In the given question, the gas in the can attains the temperature of its environment.
P₁ = 3 atm,
T₁ = 25 °C = (273.15 + 25) K = 298.15 K,
P₂ = ?
T₂ = (55 °C = 273.15 + 55) K = 328.15 K
Substituting the values in the equation
3/298.15 = P₂/328.15
P₂ = 3 × 328.15/298.15
P₂ = 3.3 atm
Therefore, the pressure inside the container will be 3.3 atmospheres
distringuish between zeotropic and azeotropic mixtures
Answer:
The terms azeotropic and zeotropic are opposite to each other. The key difference between azeotropic and zeotropic mixture is that the dew point and bubble point of an azeotropic mixture intersect, whereas the dew point and bubble point of a zeotropic mixture are distinguishable.
Explanation:
organic compounds on basis of carbon skeleton
Answer:
Acyclic or Open-chain compounds. Cyclic or Closed-chain compounds.
4. The formation of an ionic bond involves the
a. transfer of electrons.
b. transfer of neutrons.
c.
transfer of protons.
d. sharing of electrons.
[tex] \huge \mathrm{Answer࿐ }[/tex]
The formation of Ionic bond involves Transfer of electrons.
Correct answer is A.) transfer of electrons
_____________________________
[tex]\mathrm{ \#TeeNForeveR}[/tex]
Give two different conditions under which long chain hydrocarbons may be cracked.
Answer:
Various methods can be used for cracking, eg catalytic cracking and steam cracking: Catalytic cracking uses a temperature of approximately 550°C and a catalyst known as a zeolite which contains aluminium oxide and silicon oxide. Steam cracking uses a higher temperature of over 800°C and no catalyst.
determine the mass of IF5 in a 15.88 L sample at 378 K and 0.935 atm
The mass of [tex]IF_5[/tex] that would be in a 15.88 L sample at 378 K and 0.935 will be 106.51 grams.
Ideal gas problemThe problem can be solved by first using the ideal gas equation to know the number of moles of the gas that is present.
PV = nRT
P = 0.935, V = 15.88 L, T = 378 K, R = 0.082
Making n the subject of the formula:
n = PV/RT
= (0.935x15.88)/(0.082x378)
= 0.48 moles of the gas
Recall that, mass = mole x molar mass
The molar mass of [tex]IF_5[/tex] is 221.89 g/mol
Mass of 0.48 moles [tex]IF_5[/tex] = 0.48 x 221.89
= 106.51 grams
In other words, the mass of [tex]IF_5[/tex] that would be in a 15.88 L sample at 378 K and 0.935 is 106.51 grams.
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Select the correct answer. Which is true according to the law of conservation of energy? A. In a closed system, the total amount of energy in the universe keeps on changing. B. The supply of energy is limited, so it is essential to conserve it. C. In a closed system, energy can be created and destroyed. D. In a closed system, energy cannot be used faster than it is created. E. In a closed system, the total energy always remains constant.
in the image there is answer okk
Which statement is true about the electric field?
Question 3 options:
The field points away from positive charges and toward negative charges.
The strength of the field increases proportional to the charge that creates it.
The strength of the field decreases proportional to the square of the distance from the charge.
All of the above
Which substance reacts with an acid or a base to control pH?
buffer
salt
titration
sodium ion
Answer:
Your answer would be a buffer, they control pH levels.
Explanation:
Buffer is a substance that reacts with an acid or a base to control pH. Hence, option A is correct.
What is pH?pH is a measure of how acidic/basic water is.
Buffers are solutions that resist a change in pH after adding an acid or a base. Buffers contain a weak acid (HA) and its conjugate weak base (A−).
Hence, option A is correct.
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If 160 grams of a 200-gram sample of gold-198 decay in 6.25 days, what is the half-life of gold-198?
The half-life of gold-198 is 2.77 days
What is half-life of gold-198?Gold-198 decays with a half-life of 2.7 days to stable mercury-198 by emission of ß particles of maximum energy 0.960 Mev and Y -rays of energies 0.412, 0.68 and 1.09 Mev as shown schematically in In a gold grain, the thickness of the enveloping sheath of platinum is such that the ß particles: The amount of time it takes to disintegrate by half an initial amount. For a given reaction, a reactant's half-life t1/2 is the time it takes for its concentration to reach a value which is the arithmetic mean of its initial and final (equilibrium) value.Since Au-198 is 200 g originally and it decays to 160 g, so 40g leftthe fraction decay is 40/200 = 0.2the time base is 6.25 daysln0.2/6.25 = -0.25k=ln2/half life therefore half-life = ln2/k = ln2/0.25half life = 2.77 daysSo, half life of gold is 2.77 daysTo learn more about half-life of gold-198 refers to:
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if 3.38g of CuNO3 IS DISSOLVED IN WATER TO MAKE 0.220 M solution what is the volume of the solution in milliliters"
Answer:
To determine the volume of the solution in milliliters, we need to know the mass of CuNO3 and the concentration of the solution.
Given that 3.38g of CuNO3 is dissolved in water to make a 0.220 M solution, we can use the following formula to calculate the volume of the solution:
Volume = (Mass of CuNO3) / (Concentration of solution)
Plugging in the given values, we have:
Volume = (3.38 g) / (0.220 M)
Converting the mass to grams and the concentration to moles/liter, we have:
Volume = (3.38 g) / (0.220 mol/L)
Calculating, we find that the volume of the solution is approximately 15.36 liters.
To convert the volume to milliliters, we can multiply the volume in liters by 1000. In this case, the volume in milliliters is 15,360 ml.
Therefore, the volume of the solution in milliliters is approximately 15,360 ml.
Explanation:
How are fossils useful to scientists?
Answer:
Yes they are
Explanation:
Answer:
Fossils are traces of ancient life. Scientists use fossils to gather information about the lives and evolutionary relationships of organisms, for understanding geological change.
Aşağıdakilerden hangisi ülkemizde nesli tüken-
me tehlikesi taşıdığı için koruma altına alınan
canlılardan birisidir?
A) Koyun
B) At
Kardelen çiçeği (bitkisi)
D) Panda
Answer:
D seçeneği doğru
Explanation:
Türkiye'de kırmızı pandalar tehlike altında. Pandaların neslinin tükenmesinin ana nedenleri:
a) Habitat tahribatı
b) Genetik varyasyon kaybı, dolayısıyla onları hayatta kalmak için daha az uygun hale getirir
Bu nedenle, D seçeneği doğrudur
How many grams are in 3.4 moles of Sulfur
Answer:
109.02 grams
Explanation:
Multiply the molar mass of sulfur by the moles: 3.4 * 32.065 = 109.02 grams
GivenL C2H2 + 5O2 ------> 4 CO2 + 2H2O
If 9.5 L of CO2 are produced, how many liters of O2 will be needed for this reaction? Show work
Answer:
101 L
Explanation:
35.0 g KOH ÷ 56.09 g/mol KOH × (1 mol H2O/ 1 mol KOH) × 18 g/mol H2O = 11.2 g H2O
35.0 g HCl ÷ 36.45 g/mol HCl × (1 mol H2O/ 1 mol HCl) × 18 g/mol H2O = 17.3 g H2O
35.0 g KOH is the limiting reactant
Separation of mixtures and purification of chemical substances
Answer:
I don't understand what to do with this
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place
over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
Molecules in both the metal and the surrounding air will start moving at higher speeds.
Explanation:
Temperature is defined as a measure of the average kinetic energy of the molecules of a body.
The greater the temperature of a body, the greater the average kinetic energy of the molecules of the body and the greater the speed of the particles of the body.
A metal at 150°C will witness an increase in the average kinetic energy of its molecules, the molecules will speed up as temperature increases.
Similarly, the hot metal plate releases heat to the surrounding air molecules by radiation causing the surrounding air molecules to experience an increase in temperature and average kinetic energy. Thus the air molecules surrounding the metal hot plate also speed up.