What is the charge of Mn in MnO4- ?
Answer: +7
Explanation: Sum of all the oxidation numbers in a polyatomic ion is equal to the charge on the ion. Thus, the total charge on the polyatomic anion is −1. Thus, the oxidation number of Mn in MnO−4 is +7.
Calculate the mass percent for a solution of 6.5 g KOH in 250 g water
Answer:
2.53%
Explanation:
mass percent = (mass of solute/mass of solution)×100%
mass percent = [6.5 g/(6.5 + 250) g]×100% = 2.53%
Hurry please need fast
In the following chemical phrase how many moles of O are there? 6
C2H602* 2
6
12
3
A gas with a volume of 250 mL at a temperature of 293K is heated to 324K. What is the new volume of the gas?
Answer:
you can simply answer vl/t1=v2/t2
Water and phosphorus with a total mass of 200 grams are added to a flask like the one below and then the flask is sealed with a rubber stopper. The flask is then heated up so that a reaction occurs but no gas from the reaction escapes the flask. How much mass would you expect to be in the flask after the reaction occurs
Answer:
h20 o3vbjbxhnnhbnkknnchemesry
The two main postulates that was given by Antoine Lavoisier are, oxygen play an important role in combustion and the other is mass of the reactant and product is conserved. The total mass will be 200g in the flask after the reaction occurs.
What is law of conservation of mass?According to Law of conservation of mass, mass can neither be created nor be destroyed. Mass can only be transformed from one form to another. The law of conservation of mass was given by Antoine Lavoisier. Every reaction in nature follow the law given by Antoine Lavoisier that is mass is always conserved.
The total mass of reactant water, phosphorous is 200g, then the total mass of product will remain same after reaction according to law of conservation of mass.
Therefore, the total mass will be 200g in the flask after the reaction occurs.
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3.) If you have 784 g of Sulfuric Acid (H2SO4), how many moles of Sulfuric
Acid is that? *
Answer:
98.07848
Explanation:
I assume you are converting between grams H2SO4 and mole. You can view more details on each measurement unit: molecular weight of H2SO4 or mol This compound is also known as Sulfuric Acid. The SI base unit for amount of substance is the mole.
Answer:
8moles
Explanation:
n=m/GFM
n=784/98.02
n=7.998
n=8moles
Suppose you used a needle to poke two holes in a sealed tube of toothpaste. One hole near the cap and one hole is in the middle of the tube. You then squeeze the tube at the base. Compare how the toothpaste will leave each needle hole. Be sure to explain using theory, why this happens.
Answer:
done this before in my science class
Explanation:
the hole by the cap will have slightly more coming out at first due to all the toothpaste pushing forward, but over time, the middle will get more do to all the front end of the toothpaste being pushed out first
(sorry if that sounded confusing im tired, heres a cat)
The hole by the cap will have slightly more coming out at first due to all the toothpaste pushing forward, but over time, the middle will get more do to all the front end of the toothpaste being pushed out first.
What is toothpaste?Toothpaste is a key part of your daily oral hygiene routine. Along with your toothbrush and floss it helps to remove food debris and plaque from your teeth and gums.
Toothpastes can come in a gel, paste or powder form. While the ingredients differ slightly, all toothpastes contain the same general components.
With some help from your toothbrush, these help to remove debris and surface stains. This ingredient helps to prevent water loss, and keeps your toothpaste from drying out or getting gummy. This is what gives your toothpaste a little bit of sweetness, and that minty fresh scent. Since these do not contain sugar, they also do not promote tooth decay.
Therefore, The hole by the cap will have slightly more coming out at first due to all the toothpaste pushing forward, but over time, the middle will get more do to all the front end of the toothpaste being pushed out first.
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What must happen to uranium before it can be used as a fuel source?
A. No changes are necessary.
B. Stable U-235 must be enriched with 3% radioactive U-238.
C. Stable U-238 must be enriched with 3% radioactive U-235.
D. Unstable U-235 must be enriched with 5% U-238 to stabilize it.
Answer:
D
Explanation:
Before it can be used in a reactor for electricity generation, however, it must undergo a series of processes to produce a useable fuel. For most of the world's reactors, the next step in making the fuel is to convert the uranium oxide into a gas, uranium hexafluoride (UF6), which enables it to be enriched.
Unstable U-235 must be enriched with 5% U-238 to stabilize it. Hence, option D is correct.
What is radioactive?Radioactivity is the phenomenon of the spontaneous disintegration of unstable atomic nuclei into atomic nuclei to form more energetically stable atomic nuclei.
Before uranium can be used in a reactor for electricity generation, however, it must undergo a series of processes to produce a useable fuel.
For most of the world's reactors, the next step in making the fuel is to convert the uranium oxide into a gas, uranium hexafluoride (UF6), which enables it to be enriched.
Hence, option D is correct.
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If 5.60 mol of a substance releases 14.9 kJ when it decomposes, what is ΔH for the process in terms of kJ/mol of reactant?
Answer:
The correct approach is "-2.67 kJ/mole". A further solution is described below.
Explanation:
The given values are:
No. of moles,
= 5.60 mol
Substance releases,
ΔH = 14.9 kJ
Now,
The ΔH in terms of kJ/mol will be:
= [tex]\frac{\Delta H}{5.60}[/tex]
On putting the given values of ΔH, we get
= [tex]\frac{-14.9}{5.60}[/tex]
= [tex]-2.67 \ kJ/mole[/tex]
What is the new concentration of a solution after 250mL of 2.5M sulfuric acid is diluted to a final volume of 700mL?
Please show your work
Answer:
The new concentration of the solution is 0.89 M.
Explanation:
In chemistry, dilution is the reduction in concentration of a chemical in a solution. This is accomplished by adding more solvent to the same amount of solute.
So, in a dilution, the amount of solute does not vary, but the volume of the solvent varies: as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.
In a dilution the expression is used:
Ci*Vi = Cf*Vf
where:
Ci: initial concentration Vi: initial volume Cf: final concentration Vf: final volumeIn this case:
Ci= 2.5 M Vi= 250 mLCf=? Vf= 700 mLReplacing:
2.5 M* 250 mL= Cf* 700 mL
Solving:
[tex]Cf=\frac{2.5 M*250 mL}{700 mL}[/tex]
Cf= 0.89 M
The new concentration of the solution is 0.89 M.
What happens when a current is applied to two electrodes immersed in pure water?
A. No electrolysis occurs, and current does not flow.
B. Oxygen, but not hydrogen, is released as a gas.
C. Electrolysis occurs, releasing oxygen and hydrogen gas.
Answer:
b
Explanation:
Gucci ghhvhjhsgjjn hvh
Answer:
B
Explanation:
Experiment: Select the DATA tab, and check that every species is selected. Click Advance year 10 times. Which fish populations increased, and which fish populations decreased?
arts Per Thousand ... Click advance year 10 times. ... Which organism was most hurt by increased storms, and why do you think this is so? ... On the Coral Reef tab I see less fish and on the Data tab I see Staghorn Coral has majorly decreased. ... B. How does this change the populations of the two species that eat algae, ...
Answer:
increase: yellow tail snapper
decrease: grouper, parrotfish, angelfish
Explanation:
A sample of nitrogen gas in a 750.0 mL sealed flask exerts a pressure of 206.58 kPa. Calculate the temperature of the gas if the flask contains 3.00 grams of gas.
Answer:
T= -99 °C.
Explanation:
Hello there!
In this case, according to the given description of the problem, it is possible for us to analyze this problem via the ideal gas equation:
[tex]PV=nRT[/tex]
However, we first calculate the moles in 3.00 grams of nitrogen gas (28.01 g/mol):
[tex]n=3.00g*\frac{1mol}{28.01g}=0.107mol[/tex]
Next, we solve for the temperature as shown below:
[tex]T=\frac{PV}{Rn}[/tex]
Next, we convert the given pressure and volume to atm and L to obtain:
[tex]T=\frac{(206.58atm/101.325)*750.0L/1000}{0.08206\frac{atm*L}{mol*K}*0.107mol}\\\\T=174.15K-273.15\\\\T=-99\°C[/tex]
Regards!
PLZ HELP PLZ PLZ ILL MARK AS BRAINLIESTT!!!!
Q.1-
Given,
mass - 10grams
volume - 24 cm³
density = mass/volume
density = 10/24
density = 0.416 g/cm³
Q.2-
Given,
mass - 700grams
volume - 1100cm³
density = mass/volume
density = 700/1100
density = 0.6363 g/cm³
Hii! i’m timed so can someone please answer quickly!
What is the frequency of this wave? 1,2,3, or 4
I cant find any answers to this question! i really appreciate it!
Count the in between joint bunches of curve lines .
First one at beginninglast one at end .And one is in middleFrequency is 3-1=2
____Al+____O2 → ____Al2O3
Which of the following sets of coefficients would correctly balance the equation and why?
A. 2, 2, 2; because you must use the same coefficient for each substance.
B. 2, 3, 2; because you must have the same number of atoms on each side of the equation.
C. 4, 3, 2; because you must have the same number of compounds on each side of the equation.
D. 4, 3, 2; because you may have the same number of atoms on each side of the equation
Answer:
D
Explanation:
You balance an equation so that all the elements have the same number of atoms on each side of the equation.
How is a TV like our brain?
Answer:
Explanation:
Because your brain and the TV are programed to do certain things. As if you're going back into a memory, and you're simply rewatching a season of Beyblade: Metal Fusion on the TV.
How much energy is released when 75g of liquid water is reduced from 65c to 0c and completely freezes?
Answer:
Q = 20377.5 Joules
Explanation:
Given the following data;
Mass = 75g
Initial temperature = 65°C
Final temperature = 0°C
Specific heat capacity of water = 4.18 J/g°C.
To find the quantity of heat released;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat.
m represents the mass of an object.
c represents the specific heat capacity of water.
dt represents the change in temperature.
Substituting into the equation, we have;
[tex] Q = 75 * 4.18 * 65 [/tex]
Q = 20377.5 Joules
If we were to add a piece of solid Cu to an aqueous solution (in water) of silver nitrate, the Silver would be replaced in a single replacement reaction forming aqueous copper (II) nitrate and solid silver. How much silver, in grams, is produced if 15.00 grams of Cu is added to the solution of silver nitrate
Answer:
50.9 g of Ag
Explanation:
Reaction is:
Cu (s) + 2AgNO₃(aq) → 2Ag (s) + Cu(NO₃)₂ (aq)
1 mol of Cu react to 2 moles of silver nitrate in order to produce 2 moles of solid silver and 1 mol of copper (II) nitrate.
We assume, the silver nitrate in excess.
We determine moles of copper → 15 g . 1mol / 63.55 g = 0.236 moles
Ratio is 1:2. 1 mol of copper produce 2 moles of silver
0.236 moles of Cu will produce (0.236 . 2) / 1 = 0.472 moles of Ag
We deterine mass of silver:
0.472 mol . 107.87 g /mol = 50.9 g
Which is not an example of a
parasite/host relationship?
A flea on a dog
A tick on a horse
A toad on a lily pad
A barnacle on a whale
Answer:
A toad on lily pad
Explanation:
have a great day
helium gas (He) effuses ___ times faster than methane (CH4)
a. 1.80
b. 2.00
c. 2.20
d. 2.40
Answer:
b 2.00
Explanation:
I am pretty sure that is right
In making her morning tea, Dorothy drops a sugar cube into some hot water. She stirs the mixture but no longer sees the sugar cube at the bottom of her mug. Based on her observation of sugar dissolving in hot water, she can properly conclude that the sugar is
Answer:
Hydrophilic
Explanation:
A hydrophilic substance is any substance that interacts efficiently with water.
Since water is a polar solvent, a hydrophilic substance must also be polar in order to interact with water since like dissolves like in chemistry.
The fact that sugar disappears in hot water indicates that sugar is a polar hydrophilic substance because only a polar solute can dissolve in water
Based on her observation of sugar dissolving in hot water, she can properly
conclude that the sugar is hydrophilic.
A substance is said to be hydrophilic when it is able to react and dissolve in
water due to the attractive force between them. Hydrophobic substances
don't dissolve in water.
In this scenario, we were told the sugar dissolved completely in water which
means that the sugar is hydrophilic.
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Describe how you could show that a compound is an acid
HELP ASAP
Which of these atoms ihas the HIGHEST reactivity?
Answer:
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Which of the following is NOT a type of mucle tissue?
Cardiac
Smooth
Striped
Skeletal
Answer:
Striped should be the answer
Look at the diagram below. According to the diagram, what substance(s) are the
reactant(s)? What substance(s) are the product(s)? Explain your reasoning.
NH3(aq) + HCI (aa)
Ammonia Hydrochloric acid
NHCI (aa)
Ammonium chloride
You will be graded on the following rubric:
luje
Answer:
NH3(aq) and HCl(aq) are the reactants, while NH4Cl(aq) is the product.
Explanation:
The hydrogen atom from the HCl molecule joins the other three in NH3 creating a four hydrogen molecule, NH4Cl.
.What is the significance of genetic variation within the population of moths during and after the Industrial Revolution in London?
Answer:
The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth. The frequency of dark-coloured moths increased at that time, an example of industrial melanism.
Explanation:
I did this on Savvas Realize got it right.
Genetic variation is said to be the difference in the hereditary sequence. After the industrial revolution, the frequency of the dark-colored moth increased dramatically more than the light-colored moths.
What is industrial melanism?
Industrial melanism was an example of the evolutionary effect that occurred in the moths where the dark-colored species were favored over the light-colored species of peppered moths.
Before the industrial population, light-colored moths were large in number which later decreased with an increase in pollution. This occurred due to an increase in the pollutants and dust deposition that altered the environment.
As the pollution increased over time the dark-colored moths became dominant and increased their population over time. This is an example of industrial melanism as the color of the body was the determining factor in survival.
Therefore, dark-colored moths were prevalent after the industrial revolution.
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Use the information provided in the table to
determine the K, for methylammonium ion, the
conjugate acid of methylamine.
X6.8 x 10-19
4.4 x 1010
2.8 x 109
2.3 x 10-11
Answer: D
Explanation:
2.3x10-11
Answer:
D. 2.3 x 10^-11
Explanation:
Look at the image below
B. Radiation
D. roasting
How do vibrations of particles behave when sounds travel through solids?
A occurs fast
C. occurs moderately
B. occurs very slowly
D. cannot be determined
In order to calculate the number of neutrons you must subtract the what from the what?
Answer:
You take the atomic, or proton number of the element, and you subtract it from the element's mass number.
Answer:
protons
Explanation:
neutrons and protons make up the mass of the atom