Answer:
C
Explanation:
is this one ok? XD
what is a 7 letter word that starts with f: Ancient plants and animals formed into rocks.
Answer:
Fossils?
Explanation:
Which of the following is an example of water in its gas state?
1. A puddle
2. Water vapor
3. A glacier
4. A cloud
What is the main gas in our atmosphere?
Answer:
Nitrogen
Explanation:
Answer:
Yes, its nitrogen. I wrote my answer earlier in the wrong spot.
Explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.
What atom has the largest atomic radius barium calcium magnesium radium
Answer:
Radium
Explanation:
It has the highest atomic number so it would have more shells, making it larger than the others.
What is the enthalpy change(Q) when 60.0 g of NaOH is dissolved in one litre of water, given that the temperature of the solution increased by 15.8 °C?
Answer:
ΔH = -44.029 KJ/mol
Explanation:
We are told that 60.0 g of NaOH is dissolved in one litre of water.
From conversion, 1 litre = 1000 g
From tables, specific heat capacity of water; c = 4.18 J/g/°C
We are given ΔT = 15.8 °C
Formula for the heat absorbed by the solution is given as;
Q = mcΔT
Where;
Q = Heat gained by the water
m = Mass of the water
c = Specific heat of water
ΔT = change in temperature
Thus;
Q = 1000 × 4.18 × 15.8
Q = 66044 J
The solution absorbed 66044 J and therefore it means that the dissolution of the salt gave off 66044 J.
Thus;
Enthalpy is; ΔH = -66044 J
Now, Mass of NaOH is 60 g.
We know that molar Mass of NaOH is 39.997 g/mol. Thus;
Converting to moles, we have;
n = 60/39.997
n = 1.5 mol
Now, enthalpy when 1.5 moles of NaOH are dissolved in water will be;
ΔH = -66044 J/1.5 moles
ΔH = -44029.33 J/mol
ΔH = -44.029 KJ/mol
Photosynthesis needs water and carbon dioxide to happen. These 2 ingredients are called _______.
What is the correct shape and polarity of a water molecule
Answer:
D
Explanation:
because both H's should be positive and O is supposed to be negative.
Which obstacle was faced by African Americans serving in the armed forces during World War II?
They were forced to serve in segregated units.
They were not subject to military conscription.
ОООО
None of them ever saw combat during the war.
They were placed under French command.
a change of state does not affect an object's what.
Answer:
Mass
Explanation:
Please please help me please please help please please help me please please help please please help me
Answer:
AU9NJ-BLVHV-TCLJS-54YTB
help please i need this
After mixing for three hours, the product is extracted into dichloromethane and the solvent is removed to give 245 mg of an oil. Using the moles of our protected aldehyde calculated earlier (2.96) and the molecular weight of the product (102 g/mol) predict the theoretical 100% yield of the product in milligrams. Round to the tenths place.
Answer:
the theoretical 100% yield of the product in milligrams is 302920 mg
Explanation:
Given the data in the question;
245 mg of an oil
Using the moles of our protected aldehyde calculated earlier (2.96)
the molecular weight of the product (102 g/mol) = 102000 mg/mol
so, the mass of aldehyde produced (100% yield) will be;
⇒ number of moles × molar mass
⇒ 2.96 mol × 102000 mg/mol
⇒ 302920 mol.mg / mol
⇒ 302920 mg
Therefore, the theoretical 100% yield of the product in milligrams is 302920 mg
PLEASE HELP ITS RLLY IMPORTANT.
Consider the model of Ammonia to the right. Which terms would be used to describe this model? Element, molecule, and/or compound? Explain your reasoning.
Suppose you want to make an acetic acid/acetate buffer to a pH of 5.00 using 10.0 mL of 1.00 M acetic acid solution. How many milliliters of 1.00 M sodium acetate solution would you need to add? The pKa for acetate buffer is 4.75.
Answer:
Explanation:
Molarity of NaOAc needed
Using the Henderson-Hasselbalch Equation calculate base molarity needed given [HOAc] = 1.00M and pKa(NaOAc) = 4.75 and [HOAc] = 1.00m.
pH = pKa + log [NaOAc]/[HOAc]
5.00 = 4.75 + log[NaOAc]/[1.00M]
5.00 - 4.75 = log [NaOAc] - log[1.00M]
log [NaOAc] = 0.25 => [NaOAc] = 10⁰·²⁵ M = 1.78
Given 10ml of HOAc, how much (ml) 1.78M NaOAc to obtain a buffer pH of 5.00.
Determine Volume of Base Needed
(M·V)acid = (M·V)base => V(base) = (M·V)acid / (M)base
Vol (NaOAc) needed = (1.00M)(0.010L)/(1.78M) = 0.0056 liter = 5.6 ml.
Checking Results:
5.00 = 4.75 + log [1.78M]/[1.00M] = 4.75 + 0.25 = 5.00 QED.
The volume of 1.00 M sodium acetate solution needed to prepare an acetic/acetate buffer of pH 5.00 using 10.0 mL of 1.00M acetic acid solution is 17.8 mL.
We can find the volume of the acetate solution with the Henderson-Hasselbalch equation:
[tex]pH = pka + log(\frac{[CH_{3}COONa]}{[CH_{3}COOH]})[/tex] (1)
Where:
[CH₃COOH] = 1.00 M
[CH₃COONa] =?
pH = 5.00
pKa = 4.75
From equation (1), we have:
[tex] log(\frac{[CH_{3}COONa]}{[CH_{3}COOH]}) = pH - pKa [/tex]
[tex] \frac{[CH_{3}COONa]}{[CH_{3}COOH]} = 10^{pH - pKa} [/tex]
[tex] \frac{[CH_{3}COONa]}{[CH_{3}COOH]} = 10^{5.00 - 4.75} = 1.78 [/tex]
Now, the volume of the acetate solution is:
[tex]\frac{n_{CH_{3}COONa}/Vt}{n_{CH_{3}COOH}/Vt} = 1.78[/tex]
Since the total volume is the same, we have:
[tex]\frac{n_{CH_{3}COONa}}{n_{CH_{3}COOH}} = 1.78[/tex]
[tex] \frac{[CH_{3}COONa]_{i}*V_{b}}{[CH_{3}COOH]_{i}*Va} = 1.78 [/tex]
Solving for Vb
[tex] Vb = \frac{1.78*[CH_{3}COOH]_{i}*Va}{[CH_{3}COONa]_{i}} = \frac{1.78*1.00M*10.0mL}{1.00 M} = 17.8 mL [/tex]
Therefore, we need to add 17.8 mL of sodium acetate solution.
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When the North Pole of one magnet is next to another North Pole of the other manger they will repel. True or false
Which of these elements has the lowest ionization energy?
A. Si
B. CI
C. S
D. Na
Answer:
D . Na
Explanation:
PLEASE HELP ME!!! i have no idea how to answer these!
Answer: Im answering this for points
DONT COME ON MY STUFF SAYING THAT I GOT SCHOOL TO DO JUST LIKE YOU AND YOUR GIVING ME IRRELEVANT ANWSERS JUST TO GET POINTS? THATS A WASTE OF MY TIME
Explanation:
Determine if the following two structures are
identical, isomers, or unrelated?
A
B
С
identical
isomers
unrelated
Answer:
its C
Explanation:
The skeletal structure shows the outline of the compound with lines and bonds. Both the structures are unrelated. Thus, option C is correct.
What are isomers?Isomers are structures with identical molecular structures but differ in the skeletal or molecular representation. They also have varied properties as compared to the parent structure.
Identical compounds are structures that have the same atoms and are arranged with the same spatial design and orientation. The number of atoms and the spatial arrangement of the two compounds is different.
Therefore, the two compounds are unrelated.
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Describe the process of two neutral atoms forming an ionic bond
oops... sorry... I need to delete this response. I was trying to answer a different question,
what changes chemical energy to something you can use
based on the law of conservation of energy its it atoms hold by strong chemical bonds
HELP ME
Elements in a vertical column on the Periodic Table have similar properties and are all members of the same
of elements.
А
molecule
B
phase
С
atom
D
group
Answer:
D group
................
Five different substances added breakers of water. Each substance begins as a white, solid powder. Which substances do not dissolve in water? Salt,sugar,starch,chalk, and bakeing powder
Answer:
Chalk is does not dissolve in water
Explanation:
i had the same question as you
Plasma can be found naturally in
O water and ice.
O stars and lightning.
O wood and metal.
O comets and asteroids.
Answer:
stars and lightning. this is the answer ok
What is the mole ratio of iron (III) chloride (FeCl3) to zinc chloride (ZnCl2) ?
2 FeCl3 + 3 Zn → 2 Fe + 3 ZnCl2
a.2:2
b.2:3
c.3:3
d.3:2
Answer:C
Explanation:
Which one of the following represents an acceptable set of quantum numbers for an electron in an atom? (arranged as n, l, ml, and ms)
2, 2, -1, -1/2
3, 3, 3, 1/2
3, 3, 3, -1/2
5, 4,- 5, 1/2
2, 1, 0, 1/2
AWNSER FAST PLEASE
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(awnsers H²O -> (awnsers H² -> (awnsers O²
awnser for all drop-down menus 1,2, or 3
Answer: The coefficients are 2, 2 and 1.
Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants.
The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for the given reaction is:
2H2o➡️2h2+o2
______ occur between molecules that have permanent intramolecular differences in elecronegativity.
A. Dipole-dipole interactions
B. Dispersion forces
C. Hydrogen bonds
Answer:
Dipole-dipole interactions
Explanation:
Generally, atmospheric pressure decreases by 1.00 mmHg as
altitude increases 10.0 m. If altitude increases 100. m, how
much would the atmospheric pressure change in atm?
Answer:
-0.0132 atm
Explanation:
Step 1: Calculate the atmospheric pressure change if altitude increases 100. m
Atmospheric pressure decreases by 1.00 mmHg as altitude increases 10.0 m. The decrease in pressure when the altitude increases 100. m is:
100. m × (-1.00 mmHg/10.0 m) = -10.0 mmHg
Step 2: Convert "-10.0 mmHg" to atm
We will use the conversion factor 1 atm = 760 mmHg.
-10.0 mmHg × 1 atm/760 mmHg = -0.0132 atm
What is the molar mass of H2CO3?
(Molar mass of H = 1.0079 g/mol; C = 12.010 g/mol; O = 15.999 g/mol)
Answer:
molar mass of H2CO3 = 72.0228
Answer:
62.02 g/mol
Explanation:
Took the test and got it right. if you have enough faith in brainly youll choose the right answer
We obviously cannot wait for million years to determine the half-life of technetium, or even years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of pulses and a count of pulses minutes later.
The question is incomplete, the complete question is;
We obviously cannot wait for 4 million years to determine the half-life of technetium, or even 87.7 years to determine the half-life of plutonium. The half-life of a substance is determined using a Geiger counter, which is essentially a tube filled with an inert gas. When a particle decays and produces radiation, it briefly ionizes the gas and produces a detectable electric pulse, which is amplified and counted by a detector (before digital displays were available, you would hear clicks and see a needle register on a dial). Determine the formula for the half-life of a substance with an initial count of No pulses and a count of N1 pulses M minutes later.
Answer:
M1/2 = 0.693/k
Explanation:
Given that the initial count rate is No pulses
The count rate after M minutes is N1
Then from;
A = Aoe^-kt
A= N1
Ao=No
I can now write;
N1 = Noe^-kM
The half life is the time taken for the activity of the radioactive nuclide to reach half its initial value. Hence;
N1/No =e^-kM = 1/2
Taking natural logarithm of both sides as shown below;
-kM1/2 = ln(1/2)
M1/2 = - (ln(1/2)/k)
M1/2 = 0.693/k