Answer:
groups
Explanation:
In chemistry, the vertical columns are known as groups and the horizontal columns are known as periods.
The National Wildlife Refuge supports _______ wildlife refuges. a. 150 b. 37 c. 550 d. 227
Answer:
C. 550
Explanation:
HGD
Answer:
C
Explanation:
Trust
what are the dangerous chemicals in the world of humans.
i believe this would be the answer
Arsenic trioxide.
Chlorine.
Hydrogen cyanide.
Nitrous oxide.
Phosgene.
Potassium cyanide (analytical reagent and purified)
Sodium arsenate (analytical reagent)
Sodium cyanide (analytical reagent)
Hope this helps! :)
Answer:
1) Sarin gas
2) Potassium cyanide
3) Botulinum toxin
4) Batrachotoxin
5) Dimethyl Cadmium
6) Fluoroantimonic Acid
7) Arsine
8) Ricin
9) Strychnine
10) Nicotine
Explanation: That's it mate.
hope it helps
The air pressure for a basketball is 0.578 atm. What is this
pressure in Pa?
Answer:
586000.
Explanation:
Answer: 58600 atm
Explanation:
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.
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SOMEONE PLEASE CLICK ON MY ACCOUNT AND ANSWER MY PREVIOUS QUESTIONS! THERE ARE 3! PLEASE HELP!!!!!!
HERE ARE THE QUESTIONS!
Olivia is a veterinary parasitologist who is studying a recent outbreak of giardia among beavers in a Colorado river. Since this is the first time she has seen beavers with this type of protozoa, Olivia is attempting to trace where they contracted it. After extensive testing, it is found that human sewage was leaking from a treatment plant nearby. This sewage contained the giardia protozoa, and the beavers picked it up in the nearby waters. Olivia now writes a research paper concerning this case in order to reclassify giardia. After her investigations, into what category is Olivia MOST likely hoping to place these protozoa in?
Group of answer choices
zoonoses
anthroponosis
ectoparasites
helminths
Although there is no denying that something killed a third of the population of Ancient Athens, there has been debate as to cause for many years. A historian who lived through it called it The Plague and so for many years, it was accepted to be Yersinia pestis, the same as the bacteria responsible for the Black Death. Recently, though, scientists have become convinced that the outbreak was actually due to typhoid. Given that this opinion of an event that occurred hundreds of years ago has only recently changed, what conclusion can be reached?
Group of answer choices
Historians understand the language of written records more clearly and have discovered that the symptoms match typhoid.
Scientists have been able to examine samples of human teeth found in the Athens area and isolated typhoid in the pulp.
A recent resurgence of typhoid in the Athens area leads scientists to believe that the climate is perfect for typhoid but not for Yersinia pestis.
There is no real reason for the change except that some scientists believe the plague is just a catch all.
As the Black Death spread up the Italian peninsula, into France, Germany, and further north, people alive in the 1300s felt that there was little they could do to protect themselves. What option might have been open to England and Scotland that the rest of Europe could not take advantage of?
England and Scotland are on an island so they could have closed their shores to ships.
England and Scotland had access to scientists who should have found a medicine.
England and Scotland have cold, wet environments that should have killed the bacteria.
England and Scotland had access to wool that could be used to create masks.
Answer:
Olivia-anthroponosis
Although-Ringworm is not life-threatening, whereas most others are.
Black Death-It was caused by bacteria instead of a virus.
Explanation:
Determine the ratio of moles of iron actually used to moles of new product actually formed. Does this molar ratio agree with the ratio from the balanced chemical equation?
equation 1.50g Cu 1 mole cu ÷ 63.5g Cu Fe ÷1 Cu 55.8gFe ÷ 1 mole = 1.32g Fe
The mole ratio of iron to copper is 1 : 1, thus, 1.31 g of iron is required to produce 1.5 g of copper.
What is the equation of the reaction between iron and copper(ii) sulfate?The reaction between iron and copper(ii) sulfate is a redox displacement reactions in which copper is displaced from its salt by iron.
The equation of the reaction is given below:
[tex]CuSO_4 + Fe \rightarrow FeSO_4 + Cu[/tex]
The mole ratio of both reactants and product is 1 : 1
moles = mass/molar massmolar mass of copper sulfate = 160 g
molar mass of Cu = 64
molar mass of iron = 56 g
mole ratio of iron to copper = 1 : 1moles of Cu in 1.5 g = 1.5/64 = 0.00234
mass of iron required = 0.00234 × 56 = 1.31 g of iron
Therefore, from the mole ratio of iron to copper, 1.31 g of iron is required to produce 1.5 g of copper.
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Relative to solids and liquids, how does air rank as a conductor of sound?.
The fuel used to power the booster rockets on space shuttles is a mixture of aluminum metal and ammonium perchlorate. the following balanced equation represents the reaction.. 3al 3nh4clo4 → al2o3 alcl3 3no 6h2o how many moles of water are produced from 373 mol al?
The moles of water that are produced from 373 moles of ammonia present in any chemical reaction is 746 moles.
What is the stoichiometry?Stoichiometry of the reaction gives idea about the amount of entities present in any chemical reaction before and after the reaction.
Given chemical reaction is:
3Al + 3NH₄ClO₄ → Al₂O₃ + AlCl₃ + 3NO + 6H₂O
From the stoichiometry of the reaction it is clear that:
3 moles of Al = produces 6 moles of H₂O
373 moles of Al = produces 6/3×373 = 746 moles of H₂O
Hence required moles of water is 746 moles.
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Use the picture below to answer the question. Comparing Wave A (blue) to Wave B (red), Wave B has a
Answer: B longer wave
Explanation:
because
. Why is it important to know the conditions under which an aqueous redox reaction takes place in order to balance the ionic equation for the reaction
Answer:
Just like with any other reaction, balancing the equation for the reaction is important so that people can know all the inputs and outputs, and know how much of each input (reactant) is needed to produce a certain amount of product.
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 .Of a 4 M solution of HCl, 1 L is diluted to 2M. What is the volume of the diluted solution?
A. 2L
B. 0. 5L
C. 8L
D. 4L
Answer:
D because i say so and i am just here to get awnsers
A gas has a volume of 450.0 mL. If the temperature is held constant, what volume would the gas occupy if the pressure were a. doubled
Answer:
225.0mL
Explanation:
Volume and Pressure are inversely related. So if the pressure is doubled the volume will be half of its original volume.
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
Why are pure or very concentrated solutions of hydrogen peroxide considered to be dangerous?.
Answer:
Explanation:
They react violently and can be used to make bombs
Pure or very concentrated solutions of hydrogen peroxide are considered to be dangerous because they can be highly reactive and can cause severe chemical burns.
A solution is a homogeneous mixture of two or more substances, where the substances are uniformly distributed throughout the mixture.
Hydrogen peroxide is a powerful oxidizer, which means that it can react with many other substances, including organic materials such as skin and clothing.
When hydrogen peroxide comes into contact with organic materials, it can rapidly decompose, releasing large amounts of oxygen gas and heat. This can result in a fire or explosion if the concentration is high enough. In addition to being a fire and explosion hazard, hydrogen peroxide can also be harmful if ingested or inhaled.In conclusion, pure or very concentrated solutions of hydrogen peroxide are considered to be dangerous because of their high reactivity and potential to cause chemical burns, fires, and explosions.
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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%
In the excerpt below, Antony is very angry. Which rhetorical strategy is he using? Logis ethos pathos
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
What is the pH of the solution if the molarity is 0.065M[H+]
The pH of a solution that has a hydrogen ion concentration [H+] of molarity 0.065M is 1.19.
How to calculate pH?The pH of a solution refers to the power of hydrogen in the solution i.e. the degree of acidity or alkalinity of the solution.
The pH of a solution with known concentration can be calculated using the following formula:
pH = - log [H+]
According to this question, a solution has a molarity of 0.065M. The pH is as follows:
pH = - log [0.065]
pH = 1.19
Therefore, the pH of a solution that has a hydrogen ion concentration [H+] of molarity 0.065M is 1.19.
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2.3 moles of Helium gas are at a pressure of 1.70 atm, and the temperature is 41°C. What is the volume of the gas?
Answer:
35 L
Explanation:
To solve this problem we use the Ideal Gas Law equation: PV=nRT
We only have to convert one unit, which is celsius to Kilometers.
P=1.70 atm
V=X
n=2.3
R=.08206
T=41+273=314K
1.70(x)=2.3(.08206)(314)
1.70x=59.26
x=34.6L
Using 2 sig figs = 35L
What are the chemical names of these ionic compounds?
Select the correct answer from each drop-down menu.
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:
What is cholesterol and how does it affect our body?
Answer:
Cholesterol is a waxy substance found in your blood. Your body needs cholesterol to build healthy cells, but high levels of cholesterol can increase your risk of heart disease. With high cholesterol, you can develop fatty deposits in your blood vessels.
Explanation:
Answer:
Cholesterol is a waxy substance found in your blood. It can affect our bodies in many ways. If you have high levels of cholesterol it can increase your risk of heart disease. Your body needs it to help build healthy cells.
Explanation:
Hope this helps:)...if not then sorry for wasting your time and may God bless you:)
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].
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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.
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Please Help ASAP
What type of change does electrolysis cause?
Reaction change
Physical change
Temperature change
Chemical change
Answer:
Chemical change
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.
Any reaction that absorbs 150 kcal of energy can be classified as.
Answer:
The Answer should be Endothermic reaction
Explanation:
Reactions in which energy is absorbed are called Endothermic reactions.
Calculate the partial pressure of oxygen given the total barometric pressure of 515 mmHg. Round to the nearest hundredth.
The partial pressure of oxygen given the total barometric pressure is : 108.15 mmHg
Given data :
Total barometric pressure = 515 mmHg
Assuming oxygen percentage = 21%
Barometric pressure dry at 37°C
Determine the partial pressure of oxygenApplying the relation below
Partial pressure = oxygen percentage * Barometric pressure
= 21% * 515 mmHg
= 108.15 mmHg
Hence we can conclude that the partial pressure of oxygen is 108.15 mmHg.
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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