Answer:
B
Explanation:
the Answer is B .
The skeletal system produce blood cells , protect organs and helps the movement of the body .
someone pleas help I have a test tomorrow so please answer this as soon as you see this. I have 30.0 grams of potassium Iodide with 24.0 grams of lead nitrate. The products of the reaction are lead iodide and potassium nitrate. What is the limiting reactant? What is the mass of the excess reactant left over?
If you dry the lead iodide and find it's mass to be 32.5 g what is the percent yield?
Again please help I have tried everything.
Answer:
Let's walk through this together, and pay close attention. The answers are bolded and underlined but I insist you to read through the whole thing and understand what's being applied here.
Write down the balanced equation first:
[tex]Pb(NO_{3})_{2} \ + \ 2KI \ ----- > \ PbI_2 \ + \ 2KNO_{3}[/tex]
24g 30g ???
To find the limiting reactant, convert both of the masses to moles and the lowest one is the limiting reagent.
Molar mass of Lead (II) Nitrate: 331.2g/mol
Molar mass of Potassium Iodide: 166g/mol
Remember: [tex]moles \ = \ \frac{mass}{molar \ mass}[/tex]
[tex]\frac{24}{331.2} = 0.0724 \ mol\ of\ Lead \ (II) \ Nitrate\\\\\frac{30}{166} = 0.180 \ mol \ of \ Potassium \ Iodide[/tex]
As you can see here, the compound with the lower mol value is Lead (II) Nitrate, meaning Lead (II) Nitrate is our limiting reactant.
To find the excess reactant which is the other reactant present, Potassium Iodide, you must do the mol to mol ratio of Lead (II) Nitrate to Potassium Iodide (Basically the numbers in front/coefficients of the compound in the balanced equation)
The ratio is 1 : 2, meaning you have to multiply the amount of mol of Lead (II) Nitrate by 2 to get the mol of Potassium Iodide.
[tex]0.0724 \ * \ 2 = \ 0.1448 \ mol \ of \ Potassium \ iodide[/tex]
Now we change the mol into mass by multiplying it by the molar mass of potassium iodide
[tex]0.1448 \ * \ 166 = \ 24.04g \ of \ Potassium \ iodide[/tex]
To get the amount of excess reactant, you have to subtract the original mass amount you had which was 30g by the mass you just got which is 24.04g
30 - 24.04 = 5.96g of Potassium Iodide is in excess left over
Our final question is to calculate the percentage yield of lead iodide, which we can do so by dividing the actual yield produced by the theoretical yield, and multiplying the answer of that by a 100 to get the percent.
We have our experimental yield which is 32.5g but we don't have our theoretical. We have to calculate it using our limiting reactant and mol ratios. The ratio of Lead (II) Nitrate to Lead (II) Iodide is 1 : 1 so all we have to is to change 0.0724 mol into the mass value by multiplying the mol with the molar mass of Lead (II) Iodide.
Molar mass of Lead (II) Iodide: 461.01g/mol
[tex]0.0724 \ * \ 461.01 = \ 33.4g[/tex]
So the theoretical yield is 33.4g and the actual yield was 32.5g
[tex]\frac{32.5}{33.4} * 100 = 97.3 \ percent[/tex]
The percentage yield of Lead (II) Iodide is 97.3%
Please Help ASAP
What type of change does electrolysis cause?
Reaction change
Physical change
Temperature change
Chemical change
Answer:
Chemical change
Please help!!!
Write the symbol and ionic equations for the reaction of
Iron oxide with carbon
Answer:
Iron (III) oxide reacts with carbon monoxide according to the balanced equation: Fe2O3 + 3CO
The air inside a beach ball is at a temperature of 25°C and
a pressure of 1. 0 atm. If the ball contains 0. 85 mol of air,
what is its volume?
Answer:
20.796 liters
Explanation:
PV = n RT R = .082057 L-atm / (K-mol)
25 C = 298.15 K
(1) * V = .85 * .082057 * 298.15
V = 20.796 liters
Which geometry or geometries are common for complexes with a coordination number of 6?.
Answer: Heyo Kenji Here! Here's your answer- Octahedral complexes have a coordination number of six, and the six donor atoms are arranged at the corners of an octahedron around the central metal ion.
Explanation: Hope this helps!
Have a nice day!
- Kenji ^^
TIME REMAINING
16:31:41
What is the name of the hydrocarbon CH3(CH2)6CH3?
butane
decane
octane
propane
Answer:
octane is the answer have a good day
Predict which one of the following halogen has the lowest electronegativity?
A. Iodine ⃝ B. Bromine ⃝
C. Chlorine ⃝ D. Fluorine ⃝
Answer:
A. lodine
Explanation:
In moving down to the halogen group E.N. decreases hence Iodine has lowest electronegativity.
Answer:
A. Iodine
Electronegativity decreases down the group as the size of the atom increases .
If the pressure is low enough, the boiling point and the melting point of water can be equal. What is this point called? Do you think this point can exist for substances other than water? Explain your reasoning.
Answer:
This is called "evaporation" when a liquid is boiling hot, it starts to evaporate. That is how clouds form! Every liquid is able to evaporate because when it's heated up, it turns into gas. That gas is vapor.
Explanation:
common sense
A 5.0 L container at equilibrium contains 0.50 mole Co, 0.25 mole H20,0.90 mole H2. The Keq = 5.0 for thi
reaction. What is the concentration of CO2 at equilibrium?
CO(E) + H2O(g) = CO2(g) + H2(e)
Answer:use thise https://www.ahschools.us/cms/lib/MN01909485/Centricity/Domain/4810/Chem%202andIB%20Chem/Equilibrium_Practice_WS_CHem_1_Answer_KEy.pdf
Explanation:
25 Points! A flashlight uses the chemical energy stored in a battery. This chemical energy is eventually converted into which two forms of energy?
A.) Mechanical and nuclear
B.) Radiant and thermal
C.) Thermal and mechanical
D.) Nuclear and electrical
Answer:A.) Mechanical and nuclear
Explanation:
iv,e got nuthing sorry im only a kid i have to leared that yet
answer:
B) Radiant and Thermal
explanation:
"In a flashlight, chemical energy in the batteries is converted to electrical energy when the circuit including the batteries, switch and light bulb is completed. The electrical energy is converted to light (electromagnetic / radiant energy) and some heat (thermal energy) by the light bulb." -https://www.crosbyisd.org/cms/lib6/TX02216626/Centricity/Domain/392/6_9C-EnergyFormsConversions.pdf
What are the components of one formula unit of caf2.
Answer:
A calcium fluoride ([tex]{\rm CaF_{2}[/tex]) formula unit includes one calcium ion and two fluoride ions.
Explanation:
The content of one formula unit of an ionic compound is exactly the same as what its empirical formula would suggest. (The empirical formula shows the atoms that form this compound, in the smallest whole number ratio.)
For example, [tex]{\rm CaF_{2}}[/tex] is the empirical formula of the ionic compound calcium fluoride. One formula unit of this compound would thus include:
a calcium atom, and two fluoride ions.However, since [tex]{\rm CaF_{2}}\![/tex] is an ionic compound, all these atoms would take the form of ions:
[tex]{\rm Ca^{2+}}[/tex] (calcium ion) for calcium, and [tex]{\rm F^{-}}[/tex] (fluoride ion) for fluorine.Thus, one formula unit of [tex]{\rm CaF_{2}}[/tex] would include [tex]1[/tex] calcium ion and [tex]2[/tex] fluoride ions.
Calculate the molarity of 6.631 g NANO3 in 100.0 mL of solution
please add steps
Taking into account the definition of molarity, the molarity of the solution is 0.78 [tex]\frac{moles}{liter}[/tex].
Definition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Molarity of a solution of NaNO₃
In this case, you know:
number of moles= 6.631 g× [tex]\frac{1 mole}{85 g}[/tex]= 0.078 moles (being 85[tex]\frac{g}{mole}[/tex] the molar mass of NaNO₃, this is,the amount of mass that a substance contains in one mole.)volume= 100 mL= 0.1 LReplacing in the definition of molarity:
[tex]molarity=\frac{0.078 moles}{0.100 L}[/tex]
Solving:
molarity= 0.78 [tex]\frac{moles}{liter}[/tex]
Finally, the molarity of the solution is 0.78 [tex]\frac{moles}{liter}[/tex].
Learn more about molarity:
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Consider the balanced equation below. 4nh3 3o2 right arrow. 2n2 6h2o what is the mole ratio of nh3 to n2? 2:4 4:2 4:4 7:2
The required mole ratio of NH₃ to N₂ in the given chemical reaction is 2:4.
What is the stoichiometry?Stoichiometry of the reaction gives idea about the number of entities present on the reaction before and after the reaction.
Given chemical reaction is:
4NH₃ + 3O₂ → 2N₂ + 6H₂O
From the stoichiometry of the reaction it is clear that:
4 moles of NH₃ = produces 2 moles of N₂
Mole ratio NH₃ to N₂ is 2:4.
Hence required mole ratio is 2:4.
To know more about mole ratio, visit the below link:
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Which describes Ernest Rutherford’s experiment?
Positive particles are fired at gold foil. Most bounce back, but some pass through.
Negative particles are fired at gold foil. Most bounce back, but some pass through.
Positive particles are fired at gold foil. Most pass through, but some bounce back.
Negative particles are fired at gold foil. Most pass through, but some bounce back.
Answer:
Positive particles are fired at gold foil. Most pass through, but some bounce back.
Answer: c
Explanation:
What is the molarity of a solution in which 250 grams of NaCl are dissolved in 2.9 L of water?
Answer:
About 1.48 M.
Explanation:
The formula for molarity is mol/L.
So firstly, you must find the amount of moles in 250 grams of NaCl.
I do this by using stoichiometry. First, I find how nany grams are in a single mole of NaCl. This is around 58.44 grams/mole. Now that I know this, I can now use a stoich table. (250 g NaCl * 1 mol NaCl / 58.44 g NaCl). I plug this into my calculator.
I get that 250 grams of NaCl is equal to about 4.28 moles.
Now I just plug into the formula!
4.28 moles/2.9 L = about 1.48
I've attached a picture of my personal notes below which shows work I have done in similar equations.
The air pressure for a basketball is 0.578 atm. What is this
pressure in Pa?
Answer:
586000.
Explanation:
Answer: 58600 atm
Explanation:
A(n) _____ may be defined as a compound which contributes hydroxide ions or increases the OH- concentration when dissolved in water.
salt
base
ester
acid
Answer:
Base
Explanation:
Bases on dissolving with water release hydroxide ions
Take a example of Sodium hydroxide
NaOH+H_2O-->Na_0+OH-What was the actual number of moles of water per formula unit cocl2?.
Cobalt chloride exists in hydrated form. Generally it prefer to form its hexahydrated form but the actual number of water molecules per formula unit is 2. Thus it forms CoCl₂.2H₂O.
What is cobalt chloride?Cobalt chloride is a metallic compound formed from the transition metal cobalt and two chlorine atoms. In fact it is a coordination complex attached with water molecules.
The property of a compound to be easily dehydrated and dry is called hygroscopic whereas the property by which a compound easily absorbs moisture and forms its hydrated form is called deliquescent.
Cobalt chloride is deliquescent in nature and absorbs water molecules forming its dihydrated, tetra hydrated and hexahydrated forms. The most common hydrate of cobalt chloride is dihydrated one and thus we can say that the number of water molecules per formula unit of CoCl₂ is 2.
To find more about cobalt chloride, refer here:
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A sample of a compound is found to contain 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen. What is the empirical formula of this compound
Answer:
The empirical formula is CH2O, and the molecular formula is some multiple of this
Explanation:
In 100 g of the unknown, there are 40.0⋅g12.011⋅g⋅mol−1 C; 6.7⋅g1.00794⋅g⋅mol−1 H; and 53.5⋅g16.00⋅g⋅mol−1 O.
We divide thru to get, C:H:O = 3.33:6.65:3.34. When we divide each elemental ratio by the LOWEST number, we get an empirical formula of CH2O, i.e. near enough to WHOLE numbers. Now the molecular formula is always a multiple of the empirical formula; i.e. (EF)n=MF.So 60.0⋅g⋅mol−1=n×(12.011+2×1.00794+16.00)g⋅mol−1.Clearly n=2, and the molecular formula is 2×(CH2O) = CxHyOz.
Part 1:
A long-distance runner is running at a constant speed of 10 km/hr. How long does it take the runner to travel 5 km?
Hours
Answer:
1/2hour
Explanation:
it takes the runner 1 hour to complete 10km
so 5km is half of 10km therefore would take half the time
hope that helps:)
MARKING BRAINLIEST!!!
When two ammonium nitrate molecules collide with each other and then chemically decompose as a result, how many NEW molecules (in total) will be produced?
The decomposition of ammonium nitrate takes place as follows :
NH4NO3 → N2O + 2H2O
Total Molecules of H = 4
Total Molecules of N = 2
Total Molecules of O = 3
The percentage of nitrogen in urea (NH 2CONH 2 ), is:
Answer:
Here's your Answer → Kindly Check The Attachment.
Answer:
Molecular mass of urea (NH 2CONH 2) × 2
× (Atomic mass of N ) + 4
× (Atomic mass of H) + (Atomic mass of C) + (Atomic mass of O) = 60
Mass percentage of N =
Total mass of N atoms in the compound / Mass of compound × 100 = 28 / 60 × 100 = 46.67
Explanation:
Hope it helps u sis.
What behavioral adaptation helps zebras protect themselves against predators?
a group of zebras in a plain
Having a tail
Having thick fur
Looking like each other
Traveling in herds
Studies have found that lab coats are typically washed every 1 to 2 weeks. These lab coats often contain harmful germs that can be transmitted to patients during routine examinations. If this happens, the infection would be considered
congenital.
iatrogenic.
morbid.
nosocomial.
asymptomatic.
zoonotic.
Answer:
The answer is nosocomical.
Explanation:
It was transmitted from a hospitial.
how would you accurently measure amplitude in this simulation what tools and parts of the simulation would you use
Answer:
i think this is correct
Explanation:
For amplitude measurements, you count the number of vertical divisions occupied by the signal's vertical signal and then multiply by the vertical scale. The example below shows the process for measuring the peak-to-peak voltage of a signal.
which word indicates that the energy in a system is negive
Answer:
Exergonic or Exothermic (see explanation)
Explanation:
If you're talking about heat energy specifically, then the term is exothermic, meaning that the system loses heat. If referring to overall energy of a system, the term is exergonic, meaning that the system does work on the surroundings and is thus losing energy.
an effervescent tablet is added to a test tube of water, producing a solution that fizzes and releases gas bubbles. The total mass of the substances and the test tube were recorded before and after the tablet was added to the test tube of water.
Answer:
The mass remains same after and before the reaction
Explanation:
This is because of law of conservation of mass
Which states that
In a chemical reaction mass is neither created nor destroyed,it remains conserved .NEED HELP PLSS:(
Values for the molar mass of nitrogen, oxygen, and nitrogen dioxide
molecules are given in the table below. What mass of nitrogen dioxide
molecules is formed when 1 mole of nitrogen reacts with 2 moles of oxygen
and forms nitrogen dioxide?
Molecule
Molar mass (g/mol)
N2
32 .00
NO2
46.01
O A. 92.02 g
O B. 23.00 g
O C. 2.00 g
O D. 46.01 g
Answer:
A: 92.02 g
Explanation:
Equation of the reaction;
N2 (g)+ 2O2(g)------> 2NO2(g)
Note that the balanced reaction equation is the first step in solving any problem on stoichiometry. Once the reaction equation is correct, the question can be easily solved...
Determine the volume of 0.107 M NaOH required to reach halfway to the stoichiometric point of the titration.
Answer:
Need more information to solve! What is the analyte? Its concentration?
Explanation:
After injuring his knee, Kai began having pain and numbness in his lower leg. The doctor said the injury damaged nerves that run all the way down his leg.
Damage to which system is causing Kai's pain and numbness?
the peripheral nervous system
the central nervous system
the endocrine system
the circulatory system