Answer:
I'll give you three examples:
Iron
Cobalt
Nickel
Given that the enthalpy of vaporization for water is:
H2O(1) ►H2O(g)
Hvap = + 44.0 kJ/mole
Calculate H for each of the following processes:
a. Evaporating 3.00 moles of water
b. Evaporating 3.00 grams of water
c. Condensing 20.0 grams of water
Answer:h
Explanation:
How many grams are in 1,000 Lutheran of C2H4
Answer:
28.05316 grams
Explanation:
Which of the following processes provides the water necessary for human A.consumption?
B.perspiration
C.evaporation
D.precipitation
E.sublimation
Answer:
c
Explanation:
I want to say c cause u got to evaporate water that is deity so u can drink it. but I might be worng
Answer:
b
Explanation:
precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzling, rain, sleet, snow, ice pellets, graupel and hail.
What causes the ocean tides to change from high tide to low tide?
Name the compound of calcium used for disinfecting water. Give its chemical formula.
Answer: the compound used in disinfecting water is called Bleaching powder. It's chemical formula is CaOCl2 ( calcium oxychloride).
Explanation:
Water is a universal solvent. It is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. Rain, springs, well, rivers, lakes and sea are natural sources of water.
Most natural water contains dissolved mineral salts, suspended impurities and germs. Therefore to make it safe for domestic and industrial use, water from natural resources undergoes in water treatment tanks:
--> coagulation,
--> sedimentation,
--> filtration and
--> disinfection.
Taking a quick glance at the whole process z water is first collected in large tanks and filtered to remove large particles. Chemical like CA(OH)2 is added to coagulate the fine particles. The coagulated particles are removed by using filter beds. Then the Bleaching powder (calcium oxychloride) is added to kill the bacteria ( disinfection). Then water is ready for use.
what do opposite electric forces do
Answer:
Charges that are opposite each other, such as positive and negative charges, draw each other. Like charges repel each other, such as two negative charges or two positive charges.
Explanation:
Answer:
Opposite electric forces attract each other.
Like if it's positive and negative they will come together.
If they are the same(positive and positive or negative and negative) they will repel each other.
Explanation:
A squirrel ran 20 meters along the fence at a constant speed for 10
seconds. It stopped for 15 seconds and then quickly ran another 30 meters
at a constant speed for 15 seconds.*
A
B
Answer:
It's D
Explanation:
Sorry for the late answer. Since the squirrel ran constant speed for 10 seconds and it ran 20 meters the first point would be at (10,20) then since it stopped to rest for 15 seconds the next point would be (25,20) finally since it ran another 30 meters for 15 more seconds the next point would be at (40,50). Sorry if the answer isn't the best, i'm bad at explaining ;w;
Which has the most gravitational potential energy- a 10 kg ball that is 2 meters high or a 10 kg ball that is 4 meters high?
Answer:
The 10 kg ball that is 4 meters high is greater than a 10 kg ball that is 2 meters high
Explanation:
From the question,
Gravitational Potential Energy of the first ball
P.E1 = mgh.................... Equation 1
Where P.E1 = Gravitational Potential Energy of the first ball, m = mass of the first ball, h = height of the first ball, g = acceleration due to gravity.
Given: m = 10 kg, h = 2 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
P.E1 = 10×2×9.8
P.E1 = 196 J.
Similarly,
Gravitational potential energy of the second ball is
P.E2 = m'gh'................... Equation 2
Where P.E2 = Gravitational potential Energy of the second ball, m' = mass of the second ball, h' = height of the second ball.
Given; m' = 10 kg, h' = 4 m
Substitute these values into equation 2
P.E2 = 10×4×9.8
P.E2 = 392 J
From the above calculation,
P.E2 is greater than P.E1.
Hence, the 10 kg ball that is 4 meters high is greater than a 10 kg ball that is 2 meters high
If 95 grams of Iron are needed to react with sulfur, how many grams of sulfur are involved in this reaction?
2 Fe + 3 S à Fe2S3
Answer:
You need a balanced equation.
2Fe(s) + 3S(s) ==> Fe2S3(s) ... balanced equation
Reactants are solid iron and solid sulfur
Product is iron(III) sulfide
A. 1.42 moles Fe x 3 moles S/2 moles Fe = 2.13 moles sulfur
B. 2.75 moles S x 2 moles Fe/3 moles S = 1.83 moles iron
HELP PLEASEEE!!!!
When 60 grams of an alloy, at 20 C is dropped into water, the alloy
absorbs 2000 Joules of heat. If the final temperature of the alloy is 35 C, what is its specific heat? show your work.
The amount of heat energy needed to heat 200 g of water from 15 °C to its boiling point, and boil it, is
can you explain it further
An isotope contains 56 protons, 54 electrons, and 74 neutrons. What is the identity of the isotope? Choose 1 answer:
Answer:
Barium.
Explanation:
Each chemical element is characterized by the number of protons in its nucleus, which is called the atomic number Z. But in the nucleus of each element it is also possible to find neutrons, whose number can vary. The atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus.
The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element. Isotopes means "same place", that is, since all the isotopes of an element have the same atomic number, they occupy the same place in the Periodic Table. So if a neutron is added to an atom, it becomes an isotope of that chemical element.
The isotopes of an element have the same chemical properties, but differ somewhat in their physical properties.
Barium has an atomic number of 56 (number of protons). Also, the mass number of this barium isotope is 130 (56 protons + 76 neutrons). Finally, since it has 54 electrons, two negatively charged electrons less than the number of positively charged protons, this isotope is a cation with oxidation number +2.
for the complete combustion of 47 g of gasoline (octane, C8H18) , the mass of oxygen consumed is
a)69.20g
b)82.45g
c)138.4g
d)164.9g
Answer: d) 164.9 g
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex] [tex]\text{Moles of octane}=\frac{47g}{114g/mol}=0.412moles[/tex]
The balanced chemical reaction is:
[tex]2C_8H_{18}(l)+25O_2(g)\rightarrow 16CO_2(g)+18H_2O(g)[/tex]
According to stoichiometry :
2 moles of [tex]C_8H_{18}[/tex] require = 25 moles of [tex]O_2[/tex]
Thus 0.412 moles of [tex]C_8H_{18}[/tex] will require=[tex]\frac{25}{2}\times 0.412=5.15moles[/tex] of [tex]O_2[/tex]
Mass of [tex]O_2=moles\times {\text {Molar mass}}=5.15moles\times 32g/mol=164.9g[/tex]
Thus 164.9 g of oxygen is consumed.
whats another name for body cells (not sex cells) that are produced by mitosis?
Answer: Diploid Cells (?)
Explanation:
Please help ASAP.....please
would you choose to buy a soft drink in a plastic bottle or an aluminium can? Explain your answer.(3 marks)
Answer:
In a bottle.
Explanation:
I would like soda in a bottle because you don't get soda stuck in the aluminum can like you do a bottle. And it's also way more efficient because bottles have caps that you can screw on later, but aluminum doesn't.
How many moles of H2O are in 359 grams of H2O
Answer:
359
i think
Explanation:
Draw the product you expect from the reaction of (R)-2-bromooctane with -CN. Use the wedge/hash bond tools to indicate stereochemistry where it exists. Include H atoms at chiral centers only. If a group is achiral, do not use wedged or hashed bonds on it.
Answer:
See explanation and image attached
Explanation:
The reaction between (R)-2-bromooctane and -CN^- is an SN2 reaction. An SN2 reaction involves a synchronous attack of the nucleophile as the leaving group is departing.
This leads to a five member transition state in which a bond is being broken and another is being made. Since the nucleophile attacks from the backside, SN2 mechanism leads to inversion of configuration as shown in the image attached.
Is the formation of CO2(g) from its elements endothermic or exothermic?
Exothermic because the ΔH is negative.
Endothermic because the ΔH is negative.
Endothermic because the ΔH is positive.
Exothermic because the ΔH is positive.
Answer: Exothermic because the ΔH is negative.
Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]
Exothermic reactions are those reactions in which heat is released and [tex]\Delta H[/tex] is negative.Endothermic reactions are those reactions in which heat is absorbed and [tex]\Delta H[/tex] is positive.
The reaction is exothermic as the heat is released during the formation of [tex]CO_2[/tex] as heat of formation of [tex]CO_2[/tex] is negative.
Bacteria make their own food through photosynthesis making them autotrophs. * True or False
Answer: true
Explanation:
true
A given sample of gas has a volume of 5.20 L at 60.°C and 1.00 atm pressure. Calculate its pressure if the volume is changed to 6.00 L and the temperature to 27°C (assume the amount of gas does not change)
Answer:
0.78 atm
Explanation:
Applying general gas equation
PV/T= P'V'/T'................ Equation 1
Where P = initial pressure, T = Initial temperature, V = Initial Volume, P' = Final pressure, V' = Final Volume, T' = Final Temperature.
make P' the subject of the equation
P' = PVT'/TV'.............. Equation 2
From the question,
Given: P = 1.00 atm, V = 5.20 L, T = 60°C = (273+60) = 333K, V' = 6.00 L, T' = 27°C = (27+273)K = 300 K
Substitute these values into equation 2
P' = (1×5.2×300)/(333×6)
P' = 1560/1998
P' = 0.78 atm.
What is the volume, in liters, of 0.250 moles of carbon monoxide at STP?
WRITE THE FORMULAS FOR THE COMPOUNDS, NOT JUST THE NAMES. INCLUDE UNITS!
How many grams of NaCl are in 3.5 mol of NaCl? Also, how many moles of NaCl are in 150 g of NaCl?
Answer:
204.5505 grams
2.5666 moles
Explanation:
For the first question, multiply 3.5 (# of moles) by 58.443 (g/mol for NaCl).
58.443 * 3.5
I'll distribute 3.5 into 58.443.
(3.5 * 50) + (3.5 * 8) + (3.5 * 0.4) + (3.5 * 0.04) + (3.5 * 0.003)
175 + 28 + 1.4 + 0.14 + 0.0105
203 + 1.4 + 0.14 + 0.0105
204.4 + 0.14 + 0.0105
204.54 + 0.0105
204.5505 grams
There are 204.5505 grams in 3.5 moles of NaCl.
For the second question, divide 150 (# of grams) by 58.443 (g/mol for NaCl). I'll convert both into fractions.
150/1 * 1000/58443
150000/58443
2.56660336 moles
2.5666 moles (rounded to 4 places to keep consistency with the first answer) are in 150 grams of NaCl.
11) How many grams are in 2.3 moles of magnesium chloride, MgCl,?
Answer:
218.98 grams
Explanation:
Given that,
No. of moles, n = 2.3
The molar mass of magnesium chloride is 95.211 g/mol.
We need to find the mass of 2.3 moles of magnesium chloride.
We know that,
No. of moles = given mass/molar mass
Let m be the given mass. So,
[tex]m=n\times M\\\\=2.3\times 95.211 \\\\=218.98\ g[/tex]
So, the required mass is equal to 218.98 grams.
One use of CaCl2 is for salting roads in the winter. How much would the freezing point of water decrease if a 3.23 molal (m) solution of CaCl2 were applied? (Kf = 1.86°C/(mol/kg) for water and i = 3 for CaCl2.)
Answer:
Freezing point of water will decrease to -18.02°C
Explanation:
We start from the formula for freezing point depression, one of the colligative properties.
ΔT = Kf . m . i
ΔT = Freezing T° of pure solvent - Freezing T° of solution
m = molality
Kf = Cyoscopic constant (specific for each solvent)
i = numbers of ions dissolved (Van't Hoff factor)
CaCl₂ → Ca²⁺ + 2Cl⁻ i = 3
We replace each data:
0°C - T° F) = 1.86°C/m . 3.23 m . 3
T°F = - 18.02°C
is 3NaOH + H3PO4--->Na3PO4 + 3H2O balanced?
Answer:
Yes
Explanation:
3NaOH + H3PO4
3Na + 3O + 3H + 3H + P + 4O
3Na + 7O + 6H + P
Na3PO4 + 3H2O
3Na + P + 4O + 6H + 3O
3Na + 7O + 6H + P
Nevada's annual precipitation averages between 21 and 24 cm. In comparison,Washington state averages between 96 and 97 cm of precipitation per year. Which of these factors has the greatest impact on the difference in precipitation between these two states?
Answer:
Mountain ranges and prevailing winds.
Explanation:
Mountain ranges and prevailing winds are the factors that is responsible for the difference in the precipitation between Nevada and Washington states. The Washington state is located along the coastal region of pacific ocean and having more mountain ranges which causes more rainfall in that region while on the other hand, Nevada state comprise of plateau, basins and far away from the ocean which is the main cause of lower rainfall as compared to Washington state.
A scientist is investigating which type of medicine would dissolve faster, a solid pill or a scoop of powder. Which hypothesis
should the scientist develop given prior knowledge about surface area?
A. Solid pills have more surface area and will take longer to dissolve.
B. Powders have less surface area and will dissolve faster.
C. Solid pills have less surface area and will not dissolve.
D. Powders have more surface area and will dissolve faster.
B.
because a solute with a smaller surface area will dissolve faster
How do emulsifiers help oil and water to mix and not separate?
Answer:
To prevent the mixture from separating substances called emulsifiers can be added. These help to form and stabilise the emulsions, preventing or slowing the water and fat/oil from separating. ... The hydrophilic end of the emulsifier molecule is attracted to the water and the hydrophobic end is attracted to the fat/oil.
125 mL of a stock HCl solution was diluted to make 300 mL of a 0.750 mol/L HCl solution. What was the concentration of the original stock solution?
Answer: c= 1.8 mol/l
Explanation: amount of substance remains same.
Amount of substance n = c1·V1 = c2·V2 and c1= c2·V2/ V1
Original concentration c1= 300 ml·0.750 mol/l / 125 ml
Identify three sources of point-source pollution.