Answer:
3.228x10⁻⁴ moles of Na2S2O3 are required
Explanation:
In iodometry, the reaction of KIO3 with Na2S2O3 is:
KIO3 + 6 Na2S2O3 + 6H⁺ → KI + 3Na2S4O6 + 3H2O + 6Na⁺
Where 6 moles of Na2S2O3 reacts per moles of KIO3.
The moles of Na2S2O3 required to reach endpoint when 0.0000538 moles of KIO3 are:
0.0000538 moles of KIO3 * (6 moles Na2S2O3 / 1 mol KIO3) =
3.228x10⁻⁴ moles of Na2S2O3 are requiredIn the US, nutritional energy is reported in Calories (Cal). One nutritional Calorie is equal to one kilocalorie (kcal). If a food package reports 250.0 Calories (Cal) per serving, how many calories (cal) are in each serving?
Answer:
2.500 × 10⁵ cal
Explanation:
1kcal= 1000 cal
From the analysis, the number of calories in each serving of a food with 250 Calories would be 250,000 calories.
According to the illustration:
1 Calories = 1 kilocalories
The food package reports 250 Calories
Hence, 250 Calories = 1 x 250 kilocalories
= 250 kilocalories
According to metrics, 1 kilocalories = 1,000 calories
Thus, 250 kilocalories = 250 x 1000 calories
= 250,000 calories
More on unit conversion can be found here: https://brainly.com/question/19420601
Consider a monoprotic weak acid ( HAHA ) that is titrated with a strong base. What is the relationship between the strength of the weak acid and the pH of the solution at the equivalence point?A. There is no relationship between the strength of the acid and the pH at the equivalence point. B. The pH at the equivalence point is always 7 in an acid base titration. C. The weaker the acid, the higher the pH at the equivalence point. D. The stronger the acid, the higher the pH at the equivalence point.
Answer:
C. The weaker the acid, the higher the pH at the equivalence point.
Explanation:
In a titration, a solution which concentration is known is added gradually to another solution of unknown concentration, until the chemical reaction between the two solutions is complete.
The pH in the equivalence point is equal to 7.00 only if both the acid and base are strong. When one or both reactants are weak, the pH in the equivalence point is not equal to 7.00.
In the equivalence point, the amount of strong base (like NaOH) added is just enough to react stoichiometrically with the weak acid. The resulting solution "only" contains the conjugated base A⁻. A solution of Na⁺A⁻ is the solution of a weak base:
A⁻ + H₂O ⇄ HA + OH⁻ Kb=Kw/Ka
In the equivalence point of the titration of a weak base with a strong base, the pH is higher than 7.00 because at this point the acid is transformed into its conjugate base.
Lying in bed you notice that you get cold every time your brother opens the door. This is most closely associated with which step in the scientific method?
Answer:
Making an observation100% sure about that....just believe me
Hope u the best and hope that helps
What is the Dependent variable?
Explanation:
Just like an independent variable, a dependent variable is exactly what it sounds like. It is something that depends on other factors. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it. Usually when you are looking for a relationship between two things you are trying to find out what makes the dependent variable change the way it does.
What mass of solid aluminum hydroxide is produced when 50.0 mL of 0.20 M aluminum nitrate is added to 200.0 mL of 0.100 M potassium hydroxide?
Answer:
0.52g of Al(OH)₃
Explanation:
The reaction of aluminium nitrate, Al(NO₃)₃, reacts with KOH, as follows:
Al(NO₃)₃ + 3KOH → Al(OH)₃ + 3 KNO₃
That means 1 mole of aluminium nitrate reacts with 3 moles of potassium hydroxide.
To find moles of aluminium hydroxide we need to determine the limiting reactant finding moles of each reactant:
Moles aluminium nitrate:
0.050L * (0.20mol / L) = 0.01 moles Al(NO₃)₃
Moles KOH:
0.200L * (0.100mol / L) = 0.02 moles of KOH
Thus, for a complete reaction of 0.02 moles of KOH are needed (Using the chemical equation)
0.02 moles of KOH * (1 mol Al(NO₃)₃ / 3 mol KOH) = 0.0067 moles of Al(NO₃)₃.
As there are 0.01 moles of Al(NO₃)₃, this is the excess reactant and KOH is the limiting reactant.
The 0.02 moles of KOH produce:
0.02 moles of KOH * (1 mol Al(OH)₃ / 3 mol KOH) = 0.0067 moles of Al(OH)₃
In mass (Using molar mass of Al(OH)₃: 78g/mol):
0.0067 moles of Al(OH)₃ * (78g/mol) =
0.52g of Al(OH)₃How is filtration done?
What is the difference between residue and filtrate?
Answer:
residue is whatever remains after something else has been removed while filtrate is the liquid or solution that has passed through a filter, and which has been separated from the filtride.
filtration id done by placing a filter paper on the beaker or container then pour the filtride then let it settle and it will pass through and you will have the fitrate and residue
Explanation:
Please it's due today
Answer:
The answer is the second one
Please i really need help
it's due today
Answer:
coke and mentos are basically just a small scale replica
Explanation:
Which elements-O2, Rb, Sb, Pt, Y, Sm, Mn, Rh, Sn, Li-will react (a) with a solution of I to generate I2; (b) with a solution of Ag' to generate Ag; and (c) with a solution of Nat to generate Na?
Answer:
a) O2, Pt, Rh
b) Rb, Y, Sm, Mn, Sn, Li
c)Rb
Explanation:
We must consider the reduction potentials of each of the species in the question.
In (a) above, all the elements whose reduction potential is higher than the redox potential for the oxidation of I^- will react with a solution of I^- to generate I2 as shown above.
In (b) above, all the strong reducing agents can donate electrons to Ag^+ and reduce it to Ag as shown above.
In (c) Rb has a more negative reduction potential than sodium hence it can react with a solution of sodium salt to generate sodium metal.
describe the dual nature of electrons (give an example)
Answer:
In 1924, the French physicist, Louis de Broglie suggested that if light has electron, behaves both as a material particle and as a wave. According to this theory, small particles like electrons when in motion possess wave properties.
Explanation:
examples
This can be derived as follows according to Planck’s equation, E = hv = hc /λ ∴ v=c/λ(energy of the photon (on the basis of Einstein’s mass energy relationship) E = mc2
( If Bohr’s theory is associated with de-Broglie’s equation then wave length of an electron can be determined in bohr’s orbit and relate it with circumference and multiply with a whole number 2πr = nλ or λ = (2πr/2π) From de-Broglie equation, λ = (h/mv).
what are the existing evidences to support the existence of pangea?
salamat.
Fossil evidence for Pangaea includes the presence of similar and identical species on continents that are now great distances apart.
A gram of gasoline produces 45 kJ of energy when burned. Gasoline has a density of 0.77 g/mL. How would you calculate the amount of energy produced by burning 48 L of gasoline?
The energy produced in the burning of gasoline = 45 kJ/g. So, amount of energy produced by burning 48 L gasoline = 45 kJ/g×36960 g = 1663200 kJ.
In this periodic table, which type of element is shown in green boxes?
A. Metalloids
B. Nonmetals
C. Noble gases
D. Metals
Answer: A
Explanation:
Metalloids
what is the the correct equation for water gas
Answer:
Water-gas A mixture of carbon monoxide (CO) and hydrogen (H2) produced by passing steam over red-hot coke using the endothermic reaction C + H2O → CO + H2.
Which term best describes the materials that make up rocks?
sand left by erosion
compressed magma
a mixture of minerals
layers of lava
Answer:
is c a mixture of minerals
Explanation:
If a neutral atom has 49 protons, how many electrons does it have?
The rate constant for the radioactive decay of tritium 3H is 0.056 1/yr. The percentage of tritium remaining after 50 years is:_________
Answer:
6.05%
Explanation:
From the question given above, the following data were obtained:
Decay constant (K) = 0.0561 /yr
Time (t) = 50 years
We can obtain the percentage of tritium remaining after 50 years by using the following formula:
Log (N₀/N) = kt /2.303
NOTE:
N₀ is the original amount.
N is the amount remaining.
K is the decay constant.
t is the time
Log (N₀/N) = (0.0561 × 50) /2.303
Log (N₀/N) = 2.805/2.303
Log (N₀/N) = 1.218
Take the anti log of 1.218
(N₀/N) = anti log (1.218)
(N₀/N) = 1.218
N₀/N = 16.52
Invert and multiply by 100 to obtain the percentage.
N/N₀ = 1/16.52 × 100
N/N₀ = 6.05%
Thus, the percentage of tritium remaining after 50 years is 6.05%
Answer:
6.08% remains after 50 years
Explanation:
The radioactive decay follows the equation:
Ln[A] = -kt + Ln [A]₀
Where [A] is concentration of reactant after time t, [A]₀ is its initial concentration, k is rate constant and t is time.
Assuming its Initial concentration is 100%
Time is 50 yr
k is 0.056 yr⁻¹
And [A] is our incognite
Ln[A] = -0.056 yr⁻¹*50yr + Ln [100%]
ln[A] = 1.805
[A] =
6.08% remains after 50 years
An electron in the first energy level of the electron cloud has
an electron in the third energy level.
Answer: A LOWER ENERGY
Explanation:
did the test
Answer:
A lower energy!
Explanation:
I know this is not much of an explanation but I took the test i hope you have an amazing day afternoon or night! Hope this helps :3
Give the location in the Periodic Table of Elements that have the same number of valence electrons.
All groups (columns) have the same number of valence electrons
All periods (rows) have the same number of valence electrons
All groups (columns), with the exception of Helium in the Noble Gases, have the same number of valence electrons
There is no trend found on the periodic table
Answer:
• All groups (columns) have the same number of valence electrons
Explanation:
Every group or column have the same number of valence electrons as a suprise. Every column is aligned in this way.
Answer:
all members within any group
Explanation:
True or false?
An apple, potato, and onion all taste the same if you eat them with your nose plugged.
Answer:
Its true I think but I may be wrong lol
Answer:
An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged An apple, potato, and onion all taste the same if you eat them with your nose plugged
Explanation:
y e s
fireworks convert chemical energy into what kind of energy
Answer:
Kinetic energy
Explanation:
Fireworks convert chemical energy into kinetic energy to send them flying upward. Hope it is correct!
HURRY
Which part of an atom is mostly empty space?
nucleus
proton cloud
electron cloud
neutron
Answer:
Electron cloud
Explanation:
If you were to scale the size of the atom up to have the nucleus be about the size of a basket ball, then the placement of the actual electrons (about the size of a large marble at this scale) throughout the cloud would be many yards away from the nucleus.
The volume of a gas decreases to half of its original volume, but the gas maintains the same
number of moles and temperature. According to the ideal gas law, what will most likely
happen to the pressure?
A. It will double.
B. It will decrease.
C. It will increase slightly.
D. It will remain the same.
Answer:
c
Explanation:
it will slightly increase
Answer:
A
It will double
What is the reason for the trend in lonization Energy? Select all that apply.
A. larger atomic mass number
B. number of energy levels around the nucleus C. number of valence electrons.
D. number of protons in the nucleus
E. number of neutrons in the nucleus
Answer:
Explanation:
A, D,E and B i think is the correct answers
Dinitrogen tetraoxide, a colorless gas, exists in equilibrium with nitrogen dioxide, a reddish brown gas. One way to represent this equilibrium is:
The question is incomplete, the complete question is shown in the image attached
Answer:
F
T
Explanation:
From the equilibrium equation;
N2O4(g) ⇄NO2(g)
We must have to remember that;
1) At equilibrium, the concentration of the species on both sides of the reaction equation may not necessarily be the same but must be held at a constant value because the rate of forward reaction equals the rate of reverse reaction.
2) The rate of forward reaction must equal the rate of reverse reaction.
If the rate of forward reaction is k1 and the rate of reverse reaction is k2. Then it follows that at equilibrium k1 = k2.
If a reaction generated 3.5 g of H2O how many moles of water were formed?
Answer:
0.19 mol H₂O
General Formulas and Concepts:
Chem
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
Given: 3.5 g H₂O from RxN
Step 2: Define conversions
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Step 3: Convert
[tex]3.5 \ g \ H_2O(\frac{1 \ mol \ H_2O}{18.02 \ g \ H_2O} )[/tex] = 0.194229 mol H₂O
Step 4: Check
We are given 2 sig figs. Follow sig fig rules.
0.194229 mol H₂O ≈ 0.19 mol H₂O
I NEED HELP ASAP PLEASE I BEG
with what?..................
Based on molecular orbital theory, the only molecule in the list below that has unpaired electrons is __________.a) C2b) N2c) F2d) O2e) Ne2
Answer:
B.
Explanation:
ive done this before trust
Name something that has zero thermal energy.
Answer:
When all molecules in a system stop moving completely, there is zero thermal energy
Explanation:
It is impossible to reach though
Chemistry of Life Practice Active 8 1 What type of organic compound is used for building cell parts?
Answer:
Carbohydrates
Explanation: