Explanation:
When the Moon passes between Sun and Earth, the lunar shadow is seen as a solar eclipse on Earth. When Earth passes directly between Sun and Moon, its shadow creates a lunar eclipse. ... But lunar eclipses do not occur every month because the Moon's orbit is tilted five degrees from Earth's orbit around the Sun.
Acts as the digestive system inside a cell. It helps to break down old or unneeded parts of the cell, and substances that have been brought into the cell from the outside. WHO I AM?
Answer:
I think it is enzymes
Explanation:
n today's experiment, Solutions A and B are prepared as follows. Solution A: Solution B: 2.0 mL of 3.00 x 10-4 M bromcresol green 2.0 mL of 3.00 x 10-4 M bromcresol green 5.0 mL of 1.60 M acetic acid (HAc) 2.0 mL of 0.160 M sodium acetate (NaAc) 2.0 mL of 0.200 M KCl diluted to a total volume of 50 mL diluted to a total volume of 50 mL How many mL of Solution A must be added to Solution B to give a buffer that is equimolar in HAc and Ac-
Answer:
2 mL of Solution A must be added to Solution B to give a buffer that is equimolar.
Explanation:
Given the data in the question;
First we determine the number of sodium acetate;
⇒ molarity × volume ( L )
⇒ 0.16 × 2.0 mL
⇒ 0.16 × 0.002 L
⇒ 0.00032
Now, Molarity of sodium acetate = moles / Volume(L)
⇒ ( 0.00032 / 50 ) × 1000
⇒ 0.0064
Since number of moles of acetic acid that should be added tp make equimolar solution is 0.00032
and Molarity of acetic acid is 0.16 molL⁻¹
Let X represent the volume that should be added.
so;
Molarity = Moles / Volume (L)
we substitute
0.16 = (0.00032 / X) × 1000
0.16 = 32 / X
X = 0.32 / 0.16
X = 2 mL
Therefore, 2 mL of Solution A must be added to Solution B to give a buffer that is equimolar.
Name: ___________________________ Date: __________ Period: ______ Solubility Rules Practice Worksheet Name or give the chemical formula for each of the following compounds. State whether they are soluble (will dissolve) or insoluble (will not dissolve) in solution. Use solubility rules. Chemical Formula Name Solubility NH4OH Ra(OH)2 Nickel (III) Acetate CsOH RbCl Potassium Phosphate MgS CaI2 Gold (II) Hydroxide Li3PO4 Platinum (II) Carbonate Barium Nitrate
What is the molarity of a solution?
the answer is The number of moles of a solute per kilogram of solvent
Molar concentration is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solution.
State the number of neutrons in an atom of Ne-20 and the number of neutrons in an atom of Ne-22. choose two answers * 1 point Ne 20: 10 Ne 20: 11 Ne 22: 12 Ne 22: 13
Answer:
Ne 20: 10
and
Ne 22: 12
Explanation:
Ne-20:
N = A - Z = 20 - 10 = 10 neutrons
Ne-22:
N = A - Z = 22 - 10 = 12 neutrons
N: number of neutrons
A: mass number
Z: atomic number
Can anyone just give me the answers?
Answer:
i answered you
Explanation:
1. Watch how the solubility of a gas changes as pressure is increased and then decreased during the run. Which of the following statements correctly explain the relationship between the solubility of a gas and its pressure?
A. As pressure decreases, the concentration of gas molecules in the solution increases.
B. The concentration of gas particles in the solution is higher at 4.25 atm than at 1.00 atm.
C. The solubility of a gas decreases with a decrease in pressure.
D. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm.
E. Fewer gas molecules are soluble at higher pressures.
F. More gas molecules are soluble as pressure is increased.
G. As pressure is increased, the rate at which gas molecules enter the solution decreases.
2. At a certain temperature, the solubility of N2 gas in water at 3.08 atm is72.5mg of N2 gas/100 g water. Calculate the solubility of N2 gas in water, at the same temperature, if the partial pressure of N2 gas over the solution is increased from 3.08 atm to 8.00 atm .
Answer:
A. As pressure decreases, the concentration of gas molecules in the solution increases.
D. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm.
F. More gas molecules are soluble as pressure is increased.
The solubility is 188.3 mg of N2 gas/100 g water.
Explanation:
As the pressure on the gas decreases, the volume of gas molecules in the solution increases due to having distance from each other. The solubility of nitrogen gas at 2.00 atm is twice the solubility of the gas at 1.00 atm because there is more pressure on the gas molecules so due to more compression, the gas becomes more soluble. More gas molecules are soluble as pressure is increased. The solubility is 188.3 mg of N2 gas/100 g water if the atmospheric pressure is increases from 3.08 atm to 8.00 atm. This value is calculated with the help of formula i.e. P2/P1 = S2/S1.
Write in exponential form: 34⋅34⋅34⋅34⋅34⋅34⋅34⋅34.
Answer:
34^8
Explanation:
If the atomic number of chlorine is 17 and the atomic mass is 35.5 amu, then the molar mass of chlorine is?
Answer:
If the percentage abundance of Cl-35 is x , then x×35+(100−x)37100=35.5
75% of Cl-35 and 25% of Cl-37.I hope this helped!
Explanation:
ch3-co-ch2-ch2-ch3 IUpAC name
Answer:
2-pentanone.
Explanation:
Hello there!
In this case, for the given compound and, in agreement with the octet rule, it is possible to realize that the CO is actually C=O as shown below:
CH3 - C - CH2 - CH2 - CH3
||
O
Thus, since the C=O stands for the carbonyl group within the parent chain, we infer this is a ketone and more specifically 2-pentanone as it has five carbon atoms.
Regards!
The air we breathe contains different individual gases (mostly nitrogen and oxygen). Which of the following correctly describes the air we breathe? A. mixture B. liquid C. compound D. element
Answer:
A. Mixture
Explanation:
Our air has a group of gases. For example, you said nitrogen & oxygen, Which is significantly a mixture.
How many grams water will condense when 56,500 joules of energy is removed from steam at its boiling point
Answer:
Start your streak by answering any question. You'll get bonus points from day 2.
How much heat energy is required to boil 66.7 g of ammonia, NH3? The molar heat of vaporization of ammonia is 23.4 kJ/mol.
Answer:
91.7 kJ
Explanation:
Step 1: Given data
Mass of ammonia (m): 66.7 gMolar heat of vaporization of ammonia (ΔH°vap): 23.4 kJ/molStep 2: Calculate the moles (n) corresponding to 66.7 g of ammonia
The molar mass of ammonia is 17.03 g/mol.
66.7 g × 1 mol/17.03 g = 3.92 mol
Step 3: Calculate the heat (Q) required to boil 3.92 moles of ammonia
We will use the following expression.
Q = ΔH°vap × n
Q = 23.4 kJ/mol × 3.92 mol = 91.7 kJ
Select the statement that is FLASE about this experiment. Group of answer choices Changing metal solution will affect the redox potential. To ensure consistent data, collect the redox potential values at least three times. Changing temperature will affect the redox potential. To ensure stable reading, insert the conductivity meter in the solution for at least 60 seconds. Changing concentration will affect the redox potential.
Well arranged question is;
Select the statement that is FALSE about this experiment. Group of answer choices;
A) Changing metal solution will affect the redox potential.
B) To ensure consistent data, collect the redox potential values at least three times.
C) Changing temperature will affect the redox potential.
D) To ensure stable reading, insert the conductivity meter in the solution for at least 60 seconds.
E) Changing concentration will affect the redox potential.
Answer:
D) To ensure stable reading, insert the conductivity meter in the solution for at least 60 seconds.
Explanation:
Usually, redox potential is the measure of the ability of chemical elements to gain/lose electrons from/to an electrode respectively and after which they undergo reduction or oxidation respectively.
From online sources on experiments to determine redox potential, and taking into account the nernst equation which is; E_cell = E_0 – (RT/nF)•ln Q
Where;
E_cell is cell potential
E_0 is potential of the cell under standard conditions
R is universal gas constant
T is temperature
n is the number of electrons that are transferred in the redox reaction
F is Faraday's constant
Q is reaction quotient
Now, with all that in mind and looking at the options, the one that is false is option D.
Why do scientist conduct experiments on animals?
Answer:
Animals are used in scientific research to help us understand our own bodies and how they work. This is necessary to develop new medicines. Animals are also used to safety test potential medicines before they are tested in people and to check the safety of other chemicals.
Explanation:
Question 5 of 25
Which type of reaction is shown by this general equation?
Reactants + energy - products
A. Synthesis
B. Combustion
C. Endothermic
D. Exothermic
Answer:
C Endothermic
Explanation:
a. p. e. x
True or False: Both molecules and compounds are pure substances.
Answer:
False
Explanation:
Hope this helps!
Answer:
True
Explanation:
It's because both compounds and elements are considered pure substances and a molecules is considered an element.
3. At 34.0°C, the pressure inside a nitrogen-filled tennis ball with a volume of 148 cm3 is 212
kPa. How many moles of N2 are in the tennis ball?
Answer:
0.0123 mol
Explanation:
Step 1: Convert 34.0 °C to Kelvin
We will use the following expression.
K = °C + 273.15 = 34.0 + 273.15 = 307.2 K
Step 2: Convert 148 cm³ to L
We will use the conversion factors:
1 cm³ = 1 mL1 L = 1000 mL[tex]148cm^{3} \times \frac{1mL}{1cm^{3}} \times \frac{1L}{1000mL} = 0.148L[/tex]
Step 3: Convert 212 kPa to atm
We will use the conversion factor 1 atm = 101.325 kPa.
212 kPa × 1 atm / 101.325 kPa = 2.09 atm
Step 4: Calculate the moles of nitrogen gas
We will use the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 2.09 atm × 0.148 L / (0.0821 atm.L/mol.K) × 307.2 K = 0.0123 mol
How many moles of ammonia would be required to react exactly with 0.554 moles of copper(II) oxide in the following in chemical reaction? 2 NH3(g) + 3 CuO(s)= 3Cu(s) + N2(g) + 3 H2O(g)
Atmospheric pressure decreases as altitude increases. In other words, there is more air pushing down on you at sea level, and there is less air pressure pushing down on you when you are on a mountain.If pentane (C5H12), hexane (C6H14), and hexanol (C6H13OH) are heated evenly at different altitudes.
Required:
Rank them according to the order in which you would expect them to begin boiling.
Answer:
Pentane » Hexane » Hexanol
Explanation:
Pentane and Hexane are simple molecular structured with discrete molecules having weak vanderwaals forces of attraction. But Hexane has high molecular mass than pentane hence pentane has lower boiling point than Hexane.
Hexanol has hydrogen bonds between highly electronegative oxygen atom and the hydrogen atom which break on high heat energy application hence it has high boiling point.
What characteristic should an isotope used for dating have?
O A. It should have a half-life much shorter than the age of the object
being dated.
B. It should have a half-life that is close to the age of the object being
dated.
O C. It should have a half-life that changes with time in the object being
dated.
O D. It should have a half-life much longer than the age of the object
being dated.
Answer:
B
Explanation:
took the test
D. It should have a half-life much longer than the age of the object being dated. When using isotopes for dating purposes, it is important to choose an isotope with a half-life that is significantly longer than the age of the object being dated.
What is the half-life time?The half-life is the time it takes for half of the radioactive isotopes in a sample to decay into stable isotopes. By measuring the ratio of the original radioactive isotope to the decay product, scientists can determine the age of the object.
The majority of the radioactive material would have decayed if the isotope had a half-life substantially less than the age of the artefact, making it challenging to precisely establish the age.
On the other hand, the dating procedure would become more challenging and unpredictable if the isotope in the object being dated (option C) has a half-life that varies over time.
As a result, an isotope with a long half-life offers a stronger basis for precise dating since it enables sufficient radioactive decay to take place, producing quantifiable and trustworthy data.
Learn more about isotope at:
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In butter, [H3O+] =6.0x10-7 M, what is the pH? Is butter acidic, basic, or neutral?
Answer:
Label each solution as acidic, basic, or neutral based only on the stated pH.
milk of magnesia, pH = 10.5
pure water, pH = 7
wine, pH = 3.0
Solution
With a pH greater than 7, milk of magnesia is basic. (Milk of magnesia is largely Mg(OH)2.)
Pure water, with a pH of 7, is neutral.
With a pH of less than 7, wine is acidic.
In the area with a large population of valuable ocean organisms is called a(n)
Answer:
fishery
An area with a large population of valuable ocean organisms is called a fishery. If it was correct mark me as brainiest
The chemical reaction between water and magnesium is?
Answer: hydrogen gas
Explanation: When magnesium interacts with water, it will form a hydrogen gas that ignites violently due to the excessive heat and oxygen supply.
When sodium chloride is dissolved in water, the freezing point of water _________. A. increases B. first increases, then decreases C. does not change D. decreases
The presence of a non-volatile salt will decrease the freezing point of water and this process is called depression in freezing point. Thus option D is correct.
What is freezing point?Freezing point of a substance is the temperature at which it converts from its liquid state to solid state where, both the states are in equilibrium. Freezing point of water is zero degree celsius.
The freezing point of a solvent depends on some parameters such as the bond type, molecular weight, temperature, pressure etc.
When a non-volatile solute is added to the solvent its freezing point decreases from its initial value. Because presence of non-volatile salts will affect the intermolecular attraction and thereby the energy that must be applied to freeze the compound.
Therefore, the freezing point of water decreases, when sodium chloride is added into it. Thus option D is correct.
To find more about freezing point, refer the link below;
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Show your work. 37.2 moles CO2 to oxygen atoms.
2x²=8.pls help me i really need it
Explanation:
2x²=8
x²=8/2
x=√4
x=2
hope it helps.
Answer:
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[tex] {2x}^{2} = 8 \\ {x}^{2} = \frac{8}{2} \\ {x}^{2} = 4 \\ x = \sqrt{4} \\ x = 2[/tex]
ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ
[tex] \huge\purple{ \mid{ \underline{ \overline{ \tt ꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐ }} \mid}}[/tex]
The volume of a sample of carbon dioxide gas is 26.42 L at 73.0°C. What will its volume be at 92.0°C at constant pressure?
Answer:
[tex]V_2=27.87L[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to solve this problem by using the Charles' law a directly proportional relationship to understand the volume-temperature behavior:
[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]
Thus, we solve for the final volume, V2, and make sure the temperature are in Kelvin as shown below:
[tex]V_2 =\frac{V_1T_2}{T_1} \\\\V_2=\frac{26.42L(92+273.15)K}{(73+273.15)K} \\\\V_2=27.87L[/tex]
Regards!
Estimate the salt-to-water mass ratio that would produce the necessary change in temperature (i.e., 22-25°C.) Use the mass of salt calculated in the previous question and the water-to-salt ratio to determine the volume of water needed.
Answer:
Sea water salinity is expressed as a ratio of salt (in grams) to liter of water. In sea water there is typically close to 35 grams of dissolved salts in each liter. It is written as 35‰. The normal range of ocean salinity ranges between 33-37 grams per liter (33‰ - 37‰).
The reduced coenzymes generated by the citric acid cycle donate electrons in a series of reactions called the electron transport chain. The energy from the electron transport chain is used for oxidative phosphorylation. Which compounds donate electrons to the electron transport chain
Answer:
NADH and FADH2
Explanation:
The electron transport chain yields ATP, the energy driver for the body's metabolism by using atmospheric oxygen at the mitochondria.
The role of NADH and FADH2 (nicotinamide adenine dinucleotide (NAD) + hydrogen (H) and Flavin adenine dinucleotide) becomes so important as they are responsible for giving out electrons to the electron transport chain and that is a very crucial process for cellular respiration as adenosine triphosphate is produced. The hydrogen molecule in NADH and FADH2 are lost to the waiting oxygen molecule which now forms water.