Answer:
Reducing agent - S
Explanation:
The equation for the reaction is given as;
K2Cr2O3 + H2O + S --> SO2 + KOH + Cr2O3
The balanced equation is given as:
2K2Cr2O7 + 2H2O + 3S → 3SO2 + 4KOH + 2Cr2O3
The reducing agent can be obtained by comparing the oxidation number of the elements. Increase in oxidation number signifies a reducing agent
K:
Reactant - 1
Product - 1
Cr
Reactant - +2
Product - +3
O
Reactant - -2
Product - -2
H
Reactant - +1
Product - +1
S
Reactant - O
Product - +4
S has an increase in oxidation number hence it is the reducing agent.
Although Cr has an increase in oxidation number, it occurs as a compound.
Answer is D
Relatively slow rates of chemical reaction are associated with which characteristic?
A)
High temperature
B)
Low activation energy
C).
The presence of a catalyst
D)
Strong bonds in reactant molecules
Option D : Strong bonds in reactant molecules
The strong bonds in reactant molecules sometimes needs extra energy to weaken the bond and proceed the reaction. Hence, option D is correct.
What is reaction rate ?The rate of a reaction is the rate of decrease in concentration of the reactants or decrease in concentration of the reactants or increase in the concentration of the products.
The minimum energy required to overcome the barrier potential of a reaction is called its activation energy. Hence, lower the activation energy higher will be the reaction rate.
High temperature and presence of catalyst also leads to higher rate. Strong bonds in reactants needs higher energy to weaken the intermolecular force. Thus, slower the reaction rate.
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How is stoichiometry used to calculate energy absorbed when a mass of
solid melts?
O A. Grams solid x mol/g * A Hreaction
B. Grams solid x mol/g * A Hp
C. Grams solid x mol/g * A Hfusion
O D. Grams solid x mol/g * A Hvap
Answer: Option C is correct
Grams solid x mol/g * A Hfusion
Explanation:
This is because from fusion is associated to melting and this is a process where solid particles or substances goes through transition phase and turn to liquid.
There for the stoichiometry is used to calculate energy absorbed when solid mass melt with the formula Grams solid x mol/g * A Hfusion.
If some salt were accidently spilled as it was transferred from the balance to the cup would your calculated enthalpy of solution of the salt be too high or too low
Answer:
It would be to low
Explanation:
If some salt were accidently spilled as it was transferred from balance to cup calculated enthalpy of solution of salt be too low as there will be loss in mass which would lead less solubility of salt and hence less enthalpy.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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Determine the grams of water produced when 250 grams of barium hydroxide react
with 125 grams of HCI. Refer to the balanced equation below.
Ba(OH)2 (aq) + 2HCl (aq) --> 2H2O (l) + BaCl2 (aq) (balanced)
Answer:
Explanation:
Ba(OH)₂ (aq) + 2HCl (aq) --> 2H₂O (l) + BaCl₂ (aq)
171 g 2 x 36.5 g 2 x 18 g
73 g of HCl reacts with 171 g of Ba(OH)₂
125 g HCl reacts with 171 x 125 / 73 g of Ba(OH)₂
= 292.8 g of of Ba(OH)₂
Ba(OH)₂ available is 250 g , so it is the limiting reagent .
171 g of Ba(OH)₂ forms 36 g of water
250 g of Ba(OH)₂ forms 36 x 250 / 171 g of water
= 52.63 g of water.
How many joules of heat are needed to raise the temperature of 62.0 g of ethylene glycol from 13.1 C to 40.5C?
Answer:
Q = 4133.2 J
Explanation:
Hello there!
In this case, since these calorimetry problems are based off the following heat equation involving heat (Q), mass (m), specific heat (C) and temperatures (T):
[tex]Q=mC(T_2-T_1)[/tex]
Thus, we plug in the given variables to obtain:
[tex]Q=62.0 g*2.433 \frac{J}{g\°C}* (40.5\°C-13.1\°C)\\\\Q=4133.2J[/tex]
Regards!
Which describes the greatest difference between gases and solids?
A. Solids feel softer than gases.
B. Gases are darker colors than solids.
c. Solids have stronger odors than gases.
D. Gases usually weigh less than solids.
Answer:
D)Gases usually weigh less than solids.
Answer:
D) Gases usually weigh less than solids
Explanation:
Gases don't have weight and solids do which automatically makes gases lighter because they don't have a mass like a solid.
How would the number of atoms in a 2.02g sample of hydrogen compare to the number of atoms in a 32.00g sample of oxygen
Answer:
Number of atoms is equal.
Explanation:
1 mol of anything contains NA particles.
NA is known as Avogadro's number, 6.02×10²³
We determined the moles of each compound. Both molecules are dyatomic,
H₂ → 2.02 g . 1mol / 2.016 g = 1 mol
O₂ → 32 g . 1mol / 32g = 1 mol
Both have the same amount of moles.
In conclussion, the number of atoms is the same in both samples.
What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link)
During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.
What is the amount of the leftover reactant?
0.74 grams of methane
0.89 grams of methane
1.22 grams of oxygen
1.45 grams of oxygen
Answer:
0.74
Explanation:
this is the correct answer. I followed a correct answer that had the same probelm with different values, swithxed it with mine, and got 0.75. So its basically 0.74
The transmission of thermal energy that is caused by the flow of a fluid’s particles. It can only occur with liquids and gases is...
Balance the following equations.
Answer:
A) Mg + H2SO4 → MgSO4 + H2
B) CaCO3 + 2HCl → CaCl2 + H2O + CO2
C) CaO + H2O → Ca(OH)2
D) 3Ag + 4HNO3 → 3AgNO3 + H2O + NO2
Explanation:
A) Mg + H2SO4 → MgSO4 + H2
The equation is already balanced because the number of each element in the left hand side is already equal to that in the right hand side.
B) CaCO3 + 2HCl → CaCl2 + H2O + CO2
This equation is balanced by putting 2 in front of HCl on the left hand side to balance the elements on the right hand side.
C) CaO + H2O → Ca(OH)2
Thus equation is already balanced because the number of each element in the left hand side is already equal to that in the right hand side.
D) 3Ag + 4HNO3 → 3AgNO3 + H2O + NO2
This equation is balanced by putting 3 in front of Ag and 4 in front of HNO3 on the left hand side while we put 3 in front of AgNO3 on the right side to balance the elements on the right hand side.
If an amine functional group is added to an organic compound, the name of the compound will begin with
Answer for a apple it would be happle
xplanation:
How much of a 10 M solution is needed to make 1 liter of a 1M solution?
a. 1ml
b. 1000ml
c. 10ml
d. 100ml
i dont know I hope someone knows soon take care
According to molar concentration, 100 ml of 10 M solution is needed to make 1 liter of a 1 M solution.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of two solutions, molar concentration is found out by, M₁V₁=M₂V₂.
On substitution in above formula, V₁=1×1/10=0.1 L=100 ml.
Thus, 100 ml of a 10 M solution is needed to make 1 liter of a 1 M solution.
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Help for brainliest
Answer:
those things that looks like cristals
2. If the half-life of Francium-233 is 22 minutes, how much time must elapse in order for 60 grams of a 64 gram
sample to undergo decay? In other words, after how many minutes will you only have 4 grams of the original isotope
remaining?
Answer:
88 minutes
Explanation:
64 g ---> 32g ---> 16g ---> 8 g ---> 4 g
So in total, we have 4 half lives to reach 4.0 g
therefore, 4 x 22 minutes = 88 minutes
88 minutes or four half lives are required to have 4 grams of the original isotope remaining.
What is half life?Half -life of a substance is defined as the time which is required for half of the quantity of a radioactive substance to get decayed.It is a term which is used in nuclear chemistry for describing how quickly unstable atoms undergo radioactive decay into other nuclear species by emitting particles or the time which is required for number of disintegrations per second of radioactive material to decrease by one half of its initial value.
During first half life= 64 g of isotope is present , during second half life 1/2×64=32 g of isotope is present, during third half life 1/2×32=16 g of isotope is present.during fourth half life 1/2×16=8 g of isotope is present.
As 1 half life is 22 minutes 4 half lives=4×22=88 minutes.
Thus, 88 minutes are requires for 4 g of sample to remain.
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Mr. Ragusa is approached in his lab by one of his students named Hassan. Hassan had found a bottle of nitric acid that did not have a labeled molarity and wanted Mr. Ragusa to help him find it's molarity. Mr. Ragusa filled a buret to 4.85 mL with 0.30 M NaOH. Mr. Ragusa added 5 mL of the acid to a flask and added some phenolphthalein. Mr. Ragusa hit the titration spot on, and the final volume in the buret was 43.69 mL. What is the concentration of the Nitric Acid?
Round your answer to 2 decimal places. Include a unit in your answer. (ex: 1.2M)
HNO3 + NaOH --> NaNO3 + H2O
Answer:
2.33M
Explanation:
1. First, make sure the equation is balanced. In this case it would be HNO3+NaOH --> NaNO3 + H2O. (it is already balanced here.)
2. Find the initial volume, final volume, the volume of acid, volume of NaOH.
a. Initial Volume: 4.85 mL
b. Final Volume: 43.69
c. Acid (HNO3) Volume: 5 mL
d Volume NaOH: Initial V - Final V --> 43.69 mL - 4.85 mL = 38.84 mL NaOH
3. Find moles of NaOH reacted using the volume from D. Convert this volume into Liters. Multiply the volume of NaOH by molarity of NaOH given to you before. (.30 M NaOH)
a. x mol NaOH/ .03884 L = .30 mol NaOH/ 1 mol = .011652 mol NaOH
4. Now find the moles of acid. The acid given to you in the equation is HNO3. The .011652 mol NaOH is from the moles reacted that you just found. The moles on the right side would be the co-efficient in front of the elements in the equation. Since this equation does not have any coefficients (it's already balanced), it would just be 1.
a. .011652 mol NaOH/ x mol HNO3 = 1 mol NaOH/ 1 mol HNO3.
x = .011652 mol HNO3
5. Now find the concentration, also known as molarity. Divide the .011652 mol by the volume of acid you have been given (5 mL). Before using 5 mL, divide it by 1000 to get the Liter form.
a. .011652 mol HNO3/ .005 L = 2.3304 M HNO3
I hope you understand now. God bless!
3. a. How many moles of NaCl are dissolved in 152 mL of a solution if the concentration of the solution is 0.364 M?
Answer:
Good luck man
Explanation:
Good luck man
PLEASE HELP ME If a radioactive substance has an initial mass of 50 grams
and its mass halves every 5 years, what is the number of
grams remaining after 20 years?
Answer: [tex]3.125\ g[/tex]
Explanation:
Given
Initial mass [tex]A_o=50\ g[/tex]
half-life is [tex]T_{\frac{1}{2}}=5\ years[/tex]
At any time the left amount is given by
[tex]A=A_o2^{-\dfrac{t}{T_{\frac{1}{2}}}}\\\\\text{Insert the values}\\\\A=50\cdot 2^{-\dfrac{20}{5}}\\\\A=50\cdot 2^{-4}\\\\A=\dfrac{50}{16}\\\\A=3.125\ g[/tex]
When 0.875 g. of magnesium was heated in air, 1.25 g. of magnesium oxide
(MgO) was produced. How much oxygen must be added?
Answer:
1. What is the coefficient for calcium in the balanced equation?
2 Ca + 5 NaOH → 4 Na + 2 Ca(OH)2
2. The burning of 20.0 g of acetylene (C2H2) produces what mass of carbon dioxide? You must
write the equation, balance it and solve the mass-mass problem.
a. Balanced equation:
2 C2H2 + 5 O2 4 CO2 + 2 H2O
Explanation:
Can magic 8 ball wash with water?
no links pls it’s very unhelpful
answer : i don’t knowww :)
Right spelling:
Answer: I don’t know. :)
Balance the Chemical Equation. Fill in the Missing Coefficients. GeF3 + Cs = CsF + Ge
A chemist uses hot hydrogen gas to convert chromium(III) oxide to
pure chromium. How many grams of hydrogen are needed to
convert 76 grams of chromium(III) oxide, Cr203?
Answer: 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, [tex]Cr_{2}O_{3}[/tex]
Explanation:
The reaction equation for given reaction is as follows.
[tex]Cr_{2}O_{3} + 3H_{2} \rightarrow 2Cr + 3H_{2}O[/tex]
Here, 1 mole of [tex]Cr_{2}O_{3}[/tex] reacts with 3 moles of [tex]H_{2}[/tex].
As mass of chromium (III) oxide is given as 76 g and molar mass of chromium (III) oxide [tex](Cr_{2}O_{3})[/tex] is 152 g/mol.
Number of moles is the mass of substance divided by its molar mass. So, moles of [tex]Cr_{2}O_{3}[/tex] is calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{76 g}{152 g/mol}\\= 0.5 mol[/tex]
Now, moles of [tex]H_{2}[/tex].given by 0.5 mol of [tex]Cr_{2}O_{3}[/tex] is calculated as follows.
[tex]0.5 mol Cr_{2}O_{3} \times \frac{3 mol H_{2}}{1 mol Cr_{2}O_{3}}\\= 1.5 mol H_{2}[/tex]
As molar mass of [tex]H_{2}[/tex] is 2.016 g/mol. Therefore, mass of [tex]H_{2}[/tex] is calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\1.5 mol = \frac{mass}{2.016 g/mol}\\mass = 3.024 g[/tex]
Thus, we can conclude that 3.024 g grams of hydrogen are needed to convert 76 grams of chromium(III) oxide, [tex]Cr_{2}O_{3}[/tex].
give me the type of reactions ___ CuCO3 → ___ CuO + ___ CO2
down there (pls hurry!!)
A 3.20-mol sample of gas occupies a volume of 350. mL at 300.0 K. Determine the
pressure of the gas.
Answer:
[tex]P \approx 225atm[/tex]
Explanation:
From the question we are told that:
Moles of sample n=3.20_mol
Volume V=350mL
Temperature T=300k
Generally the equation for ideal gas is mathematically given by
[tex]PV=nRT[/tex]
[tex]P=\frac{nRT}{V}[/tex]
[tex]P=\frac{3.20*0.08206*300}{350*10^{-3}}[/tex]
[tex]P=225.079atm[/tex]
[tex]P \approx 225atm[/tex]
2
A chart with the densities of four metals is shown.
Metal
Density (gicm')
Titanium
4.5
Zinc
7.1
Nickel
88
Silver
10.5
Students were given a sample of an unknown metal and told to determine
its density. They measured its mass as 26.4 g and its volume as 3.0 cm?
Use the chart to determine which metal the students were given.
Answer:
mass(m)=26.4g
volume (v)=3.0cm²
we have
density =m/v=26.4/3=8.8g/cm³
since it is equal to density of nickel.
Option C nickel is a required answer.
Answer:
[tex]\huge\boxed{\fcolorbox{green}{yellow}{option \: \: c}}[/tex]
Find the total pressure (in atm) of a mixture that contains 3 gases with the following partial pressures. Gas A is 4.2atm, Gas B is 780 mmHg, Gas C is 250.00kPa
Answer: The total pressure of given mixture that contains 3 gases is 7.68 atm.
Explanation:
Given: Partial pressure of gases is:
Gas A = 4.2 atm
Gas B = 780 mm Hg
Convert mm Hg into atm is as follows.
[tex]1 mm Hg = 0.00131579 atm\\780 mm Hg = 780 mm Hg \times \frac{0.00131579 atm}{1 mm Hg}\\= 1.02 atm[/tex]
Gas C = 250 kPa
Convert kPa into atm as follows.
[tex]1 kPa = 0.00986923 atm\\250 kPa = 250 kPa \times \frac{0.00986923 atm}{1 kPa}\\= 2.46 atm[/tex]
Total pressure is the sum of partial pressures of gases present in the mixture.
Therefore, total pressure of given mixture is calculated as follows.
[tex]P_{total} = P_{A} + P_{B} + P_{C}\\= 4.2 atm + 1.02 atm + 2.46 atm\\= 7.68 atm[/tex]
Thus, we can conclude that the total pressure of given mixture that contains 3 gases is 7.68 atm.
The VSEPR model is used mainly to do what
PLEASE HELP ME :(((
What is the relative size and composition of the universe, a galaxy, and a solar system?
Answer:
about 93 billion light years
Explanation:
The observable Universe is, of course, much larger. According to current thinking it is about 93 billion light years in diameter.
Answer:
93 miles
Explanation: We can determine the distance to the sun using the time light takes to get to Earth. Just multiply the speed of light by the amount of time it takes light to get to Earth. That's 500 seconds.
186,282 miles per second x 500 seconds = 93,141,000 miles
The sun is about 93 million miles away from Earth. It will take our fastest space shuttle moving at a constant maximum speed about 108 days to travel this same distance.