Answer:
15.2 g H2
Explanation:
2H2O -> 2H2 + O2
9.06 x 10^24 molecules x (1 mol/6.022 x 10^23 molecules) x (2 mol H2/2 mol H2O) x (1.008 g/1 mol) = 15.2 g H2
A student is heating a crystal of alum to
determine the hydrate formula. If she removes
it from the heat before all the water has been
removed, what will happen to the calculated
hydrate formula?
A. It will not be affected by the error.
B. The mole ratio will indicate less water than was
actually present.
C. The mole ratio Will indicate less alum than was
actually present.
A gas is contained in a thick-walled balloon. When the pressure changes from ___ kPa to 114 kPa, the volume changes from 0.654 L to 1.32 L and the temperature changes from 596 K to 715 K.
Answer: 191.8
Explanation:
Answer:
191.8
Explanation:
I know the answer is correct I got the exact same one :)
In what form metals are found in nature
Answer:
Metals in nature are found in rock form, mineral forms etc..
Answer:
Metals are found in rock
2. A chemical's flash point is the
You have to prepare a pH 5.00 buffer, and you have the following 0.10 M solutions available: HCOOH (pka=3.74), HCOONa, CH3COOH (pka=4.74), CH3COONa, HCN (pka=9.31), and NaCN. Which solutions would you use?
Answer:
CH3COOH - CH3COONa since its pKa is closest to the required pH.
Explanation:
Hello there!
In this case, in agreement with the theory of buffers as solutions able to withstand severe pH changes due to the addition of acidic or basic substances, it is possible to set up a generation equilibrium expression for the acids herein given:
[tex]Ka=\frac{[A^-][H_3O^+]}{[HA]}[/tex]
Which leads to the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[A^-]}{[HA]} )[/tex]
Thus, since all the buffers have [A-]=[HA]=0.10M, the log part becomes 0 and therefore the best buffer will have the closest pKa to the required pH, which is CH3COOH - CH3COONa since its pKa is 4.74.
Best regards!
[tex]CH_3COOH\; and\; CH_3COONa[/tex] can be used to prepare a pH buffer, if 0.10 M solution available of the solutions.
What is buffer?Buffer is a solution, that resist change in pH, by adding or removing H+ ions to the solution.
Maintaining a constant pH is necessary to complete many reactions.
In blood, bicarbonates maintain the pH of the body.
[tex]CH_3COOH\; and\; CH_3COONa[/tex] have approx the nearest pH, so they can be used to make a buffer.
Thus, the correct options are [tex]CH_3COOH\; and\; CH_3COONa[/tex]
Learn more about buffer
https://brainly.com/question/24188850
Chlorofluorocarbons may be harming the ozone layer by ____.
a.
adding more ozone molecules
c.
destroying ozone molecules
b.
blocking ultraviolet radiation
d.
adding carbon dioxide molecules
Please select the best answer from the choices provided
Answer:
The awnser is C. Hope that helps!!!
How many internal parts or “organelles” are there in a plant cell?
please i need a answer!
Answer: it has 2 parts
Explanation:
Firstly, plant cells have a cell wall that surrounds the cell membrane, whereas animal cells do not. Plant cells also possess two organelles that animal cells lack: chloroplasts and a large central vacuole
What would happen to the position of the equilibrium when the following changes are made to the reaction below?
2HgO(s) ↔ Hg(l) + O2(g)
1.) The pressure on the system decreases.
Which describes bonding electrons in a polar covalent bond?
electrons that are not shared equally
electrons that are shared in diatomic molecules
electrons that are shared equally
Answer:
I think the third one
Explanation:
i think
Answer:
electrons that are NOT shared equally
Explanation:
You have 1.2 x 10^25 particles of NiCO3. How many grams are present?
Answer:
2365.0 g
Explanation:
First we convert 1.2 x 10²⁵ particles into moles, using Avogadro's number:
1.2 x 10²⁵ particles ÷ 6.023x10²³ particles/mol = 19.9 molThen we convert 19.9 moles of NiCO₃ into grams, using the molar mass of NiCO₃:
NiCO₃ Molar Mass = 118.702 g/mol19.9 mol * 118.702 g/mol = 2365.0 g- Rachel performed an investigation to study the thermal conductivity of four different materials. She started with four identically shaped rods—each made of a different material. Then, she placed one end of each rod into a pot of boiling water, which was at 100°C.
- After five minutes, Rachel measured the temperatures of the ends of the rods that were sticking up out of the pot to see whether they got hot. Her results are shown below.
Thermal Conductivity Investigation
Material Temperature of End of Rod After 5 Minutes
Material 1 41°C
Material 2 53°C
Material 3 98°C
Material 4 59°C
- Rachel knows that one of the materials is copper and that copper conducts thermal energy very well. Which of the materials is most likely copper?
A.
material 1
B.
material 3
C.
material 4
D.
material 2
Answer:
I will have the maths book
Answer:98
Explanation:
Which sound frequency with a human ear be able to detect? Select ALL correct answers.
100 Hertz
1,000 Hertz
10,000 Hertz
100, 000 Hertz
The answers are 100, 1,000, 10,000 if your are with K12
Answer:
100 HZ 1,000 HZ 10,000 HZ there you go :)
Answer:
100 hertz, 1,000 hertz, and 10,000 hertz
Explanation:
I took the k12 test :)
Is c6h4cl2 soluble in water?
Answer:
slightly but poorly
Explanation:
it is a white crystalline solid that is practically insoluble in water and soluble in ether, chloroform, carbon disulfide, benzene, alcohol and acetone.
Which statement defines enzymatic activity? Enzymes are required to slow down biological reactions within cells. Specific enzymes can catalyze a wide variety of chemical reactions. Enzymes regulate cellular functions through feedback mechanisms. Enzymes bind substrates so that reactive groups have many different orientations.
Answer:
Enzymes are required to slow down biological reactions within cells,
this could be not sure
Answer:
D
Explanation:
Enzymes bind substrates so that reactive groups have many different orientations.
The gases are contained in a reaction vessel and are in equilibrium at 298 K
X2Zi â 2XZ2(g)
a. Activation energy
b. Total mass of the system
c. Molar concentration of XZ4(g)
d. Number of molecules present
e. Equilibrium constant
1. Is decreased by the addition of a catalyst?
2. Is decreased when the volume of the reaction vessel is increased and equilibrium is reestablished at 298 K?
Answer:
1) Activation energy ( A )
2) Molar concentration of X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) ( C )
Explanation:
X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) ⇄ 2XZ
1) Activation energy Is decreased by the addition of a catalyst
while Equilibrium constant will Increase and other options will still remain unaffected
2)Molar concentration of X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) Is deceased when the volume of the reaction vessel is increased and equilibrium is reestablished at 298 K
while Number of molecules present will Increase
A 250mL beaker is submerged in a large container of Liquid A and turned upside down, and another 250mL beaker is submerged and turned upside down in a large container of Liquid B. Hydrogen H2 gas is bubbled into each upside-down beaker until 100mL of liquid has been displaced. The masses mA and mB of hydrogen inside each beaker is then chemically determined. Note for advanced students: you may assume the solubility of H2 in either liquid is very low.
a. mx will be greater than my
b. mx will be less than my
c. mx will be equal to my
d. It's impossible to predict whether mx or my will be greater without more information.
Answer:
Mx will be less than My.
Explanation:
The correct option is - Mx will be less than My.
Because, liquid X have been higher viscosity and vapor pressure than liquid B.
Vapor pressure of liquid A is greater, so the amount of liquid X will vaporized greater and H2 gas has been displaced greater from the beaker as compared to liquid Y.
The amount of H2 in liquid Y remains greater in beaker as compared to liquid X.
So, Mx will be less than My.
Air pressure is greatest ____ because there are more molecules of air pushing down from above.
a.
at the top of the mountain
c.
in the troposphere
b.
at sea level
d.
in the exosphere
Please select the best answer from the choices provided
Answer:A
Explanation:
I just know it
Answer:
The correct answer is B
.....plllzzz heeelp me fast??
Answer:
Explanation:
It is 11
A reaction has a theoretical yield of 27.6 g. When the reaction is carried out, 13.4 g of the product is obtained. What is the percent yield?
A) 48.6 %
B) 206 %
C) 370 %
D) 64.7 %
Answer:
yee I'm excellent in maths and science
Calculate the mass (grams) of 0.750 moles of Al2(Cr2O7)3
Answer:
526g is the mass of this sample
Explanation:
To solve this question we must, as first, find the molar mass of Al₂(Cr₂O₇)₃ using the periodic table. The molar mass is defined as the mass of this compound per mole. With this value we can find the mass in 0.750 moles as follows:
Molar mass Al₂(Cr₂O₇)₃
2Al = 2*26.98g/mol = 53.96g/mol
6 Cr = 6*51.9961g/mol = 311.9766g/mol
21 O = 21*15.999g/mol = 335.979g/mol
53.96g/mol + 311.9766g/mol + 335.979g/mol
= 701.9156g/mol
The mass of 0.750 moles is:
0.750 moles * (701.9156g / mol) =
526g is the mass of this samplePlz help me well mark brainliest if correct!!
Answer:
A
Explanation:
Waxing means getting bigger.
Waning is.. you guessed it... the exact opposite.
Answer:
a
Explanation:
..........................
Help me! Who ever gets to answer and has the best answer gets brainliest
Answer:
Decay-the breakdown of dead plants..
Earth- thermal energy comes from deep inside...
Fires- these consume feul...
Explanation:
Answer:
Fires - These consume fuel and covert chemical energy stored in that fuel into thermal, light and sound energy
Decay - The breakdown of dead plants and animals produces thermal energy
Earth - Thermal energy comes from deep inside and is called geothermal energy
Explanation:
Fires, when you burn wood, you convert chemical energy from the wood into thermal (warmth from the fire), light (glow from the fire), sound (crackling sound of wood burning)
Decay - I can't explain that one to you but there are power plants that use decomposition to produce energy
Earth - Beneath the crust there is the mantle, which consists of molten rock which produces a lot of thermal energy. This can be seen in geysers, where the molten rock heats water and hot water can burst out of the surface. Applies to hot springs too
NEED HELP ASAP
Imagine that you have a sample of a substance. You cannot physically separate that substance into components. You also cannot chemically separate that substance into components. Which of the following are true about your sample?
The sample is made up of multiple elements. t or f
The sample is made up of one type of atom. t or f
The sample is made up of several types of atoms. t or f
The sample is made up of a single element. t or f
Answer:
The sample is made up of a single element. t or f
Explanation:
Forgot about the t or f! Its true.
Dam bro.....
1. T
2. F
3. T
Answer:
i think its the 3 thired one sorry if rong but good luck
Explanation:
29. Which is the electron configuration of an atom
in the excited state?
(1) 1s 2s²2p2
(2) 1s 2s22p'
(3) 1s 2s22p5352
(4) 1s²2s²2p%35'
6. Menthol is a member of the terpene family of natural products. It exists in a (1R, 2S, 5R) form and a (IS, 2R, 5S) form. Are these two compounds enantiomers or diastereomers?
What is the hydronium ion concentration of a solution whose pH is 4.12?
a. 5.1 x 10–6 M
b. 7.6 x 10–5 M
c. 6.4 x 10–5 M
d. 4.4 x 10–8 M
Formula mass of Ca(NO2)2
Answer: 132.1 g/mol
Explanation: 40.08 + 2·(14.01+2·16)
I need help please. No links/ irrelevant answers or I will report you
Data:
2Fe(s) + O2(g) => 2FeO(s) ΔH = -545.6 kJ
4Fe(s) + 3O2(g) => 2Fe2O3(s) ΔH = -1,643.6 kJ
3Fe(s) + 2O2(g) => Fe3O4(s) ΔH = -1,117.7 kJ
Given the data above, determine the heat of reaction, ΔH, for the reaction:
2 Fe3O4(s) => 2 Fe2O3(s) + 2 FeO(s)
Answer:
ΔH = 46.2 kJ
Explanation:
Hello there!
In this case, according to the given set of reactions and the required one, it is possible to apply the Hess' rule in order to realize the following manipulations to obtain the required reaction:
1. Keep this reaction as it is.
2Fe(s) + O2(g) => 2FeO(s) ΔH = -545.6 kJ
2. Keep this reaction as it is.
4Fe(s) + 3O2(g) => 2Fe2O3(s) ΔH = -1,643.6 kJ
3. Reverse double this reaction so that we obtain:
2Fe3O4(s) => 6Fe(s) + 4O2(g) ΔH = -(-1,117.7 kJ)*2=2235.4kJ
Add them up to obtain:
2Fe(s) + O2(g) + 4Fe(s) + 3O2(g) + 2Fe3O4(s) => 6Fe(s) + 4O2(g) +2Fe2O3(s) + 2FeO(s)
Simplify common terms to obtain:
2 Fe3O4(s) => 2 Fe2O3(s) + 2 FeO(s)
Therefore, the enthalpy of such reaction is:
ΔH = 2235.4kJ -545.6 kJ -1,643.6 kJ
ΔH = 46.2 kJ
Best regards!
Can someone help me I am stuck on this question it would mean the world if u helped me =) have a nice day!
2. According to Newton's second law of motion, in which of these situations is the object
accelerating? a. A book on a shelf b. A rock sitting on the ground c. A helium balloon tied to a
lamppost d. A ball that has been thrown upward
Answer:
the Answer is A ball that has been thrown upward