Answers
Answer:
15-21 is 6
Explanation:
Related Questions
how do you think petals protect the internal structures of a plant?
Answers
Answer:
hmm that is a very tricky question. probably from over flooding with water
how many moles are 2.54×10^29 molecules of H20
Answers
Answer:
Explanation: The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.
Please help help help help
Answers
Answer:
50000 dollars or 5 e5
Explanation:
Mr. Garibay has [tex]5.0 * 10^4[/tex] dollars in his bank.
Scientific notation represents the data in the format of expanded number or with e character.
For instance, 5.0 * 10^4 dollars = 50000 dollars or 5 e5
Please help I need answer soon.
A volcanic mountain made up of volcanic ash, cinders, and bombs is called a ___________________.
Answers
Answer:
Cinder cone
Explanation:
um can someone help balance this...id.k how
Answers
CH4 + 2 O2 = CO2 + 2 H2O
i believe it's this :p
b) If 35 grams of copper (II) chloride react with 20 grams of sodium nitrate, how much sodium chloride can be formed? what is the limiting reactant ? what is the excessive reactant ?
Answers
Answer:
CuCl₂ is the excessive reactant and NaNO₃ the limiting reactant, 13.7g of NaCl can be formed.
Explanation:
Based on the reaction:
CuCl₂ + 2NaNO₃ → 2NaCl + Cu(NO₃)₂
To solve the problem we must convert the mass of each reactant in order to find limiting reactant as follows:
Moles CuCl₂ -Molar mass: 134.45g/mol-:
35g * (1mol / 134.45g) = 0.26 moles
Moles NaNO₃ -Molar mass: 84.99g/mol-:
20g * (1mol / 84.99g) = 0.235 moles
For a complete reaction of 0.235 moles of NaNO₃ there are required:
0.235 moles NaNO₃ * (1 mol CuCl₂ / 2 mol NaNO₃) = 0.118 moles CuCl₂
As there are 0.26 moles CuCl₂,
CuCl₂ is the excessive reactant and NaNO₃ the limiting reactantAs 2 moles of NaNO₃ produce 2 moles of NaCl, he moles of NaCl produced are: 0.235 moles NaCl. The mass is:
Mass NaCl -Molar mass: 58.44g/mol-:
0.235 moles NaCl * (58.44g / mol) =
13.7g of NaCl can be formedNeed help please!! To obtain pure lead, lead (II) sulfide is burned in an atmosphere of pure oxygen. The products of the reaction are lead and sulfur trioxide (SO3). Write a balanced chemical equation for this process. How many grams of lead will be produced if 2.54 grams of PbS is burned with 1.88 g of O2? Express your answer to the correct number of significant figures. Be sure to show all steps completed to arrive at the answer. (Hint: be sure to work the problem with both PbS and O2).
Answers
The equation of the reaction is [tex]2PbS + 3O_{2} --- > 2Pb + 2SO_{3}[/tex] and the mass of lead produced is 2.28 g
What is the equation?The term equation is the means by which we could be able to represent what is going on in the reaction system on a piece of paper. Thus, when we write a reaction equation, it is a representation of the process that is going on in the system. By the use of the stoichiometry of the reaction we could obtain the parameters of the equation.
The balanced reaction equation is; [tex]2PbS + 3O_{2} --- > 2Pb + 2SO_{3}[/tex].
Number of moles of lead (II) sulfide = 2.54 grams/239 g/mol = 0.011 moles
Number of moles of oxygen = 1.88 g/32 g/mol = 0.059 moles
If 2 moles of lead (II) sulfide reacts with 3 moles of oxygen
0.011 moles of lead (II) sulfide reacts with 0.011 moles * 3 moles /2 moles
= 0.0017 moles
Hence lead (II) sulfide is the limiting reactant.
If 2 moles of lead (II) sulfide produces 2 moles of lead
Mass of the Lead produced = 0.011 moles * 207 g/mol = 2.28 g
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What is the pH and pOH of a 2.2 x 10^-3 HBr solution?
Answers
Answer:
The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.
Explanation:
pH - short for hydrogen potential - is a measure of the acidity or alkalinity of a solution. So the pH is a parameter that indicates the concentration of hydrogen ions [H]⁺ that exist in a solution.
The pH is expressed as the negative base 10 logarithm of the hydrogen ion concentration. This is represented by:
pH= - log [H⁺]
pH is measured on a scale of 0 to 14. On this scale, a pH value of 7 is neutral, which means that the substance or solution is neither acidic nor alkaline. A pH value of less than 7 means that it is more acidic, and a pH value of more than 7 means that it is more alkaline.
HBr is a strong acid. Then, in aqueous solution it will be totally dissociated. So the proton concentration is equal to the initial concentration of acid:
[H⁺]= [HBr]= 2.2*10⁻³ M
So:
pH= - log (2.2*10⁻³)
pH= 2.66
On the other hand, pOH is a measure of the concentration of hydroxyl ions in a solution. The sum of pH and pOH equals 14:
pH + pOH= 14
2.66 + pOH= 14
pOH= 14 - 2.66
pOH= 11.34
The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.
Would glucose be considered a natural resource of synthetic product?
Answers
hello my BEANS i want to know if u r a girl or a boy so if i call u a boy and u r a girl i am not a bad person i am 13 and i am good and not a robot pls dont repot me pls
Answers
Answer:
okie
Explanation:
imma girl
2.0 L of a gas is at STP. What is the new pressure in kPa if the volume changes to 10.5 L and the temperature and # of molecules remain constant?
Answers
Answer:
What is the new volume if the temperature is constant? V=2.50L. P = lookPa. P2=40k Pa. V2 = x. PV = P2 ... If a sample of gas occupies 6.8 L at 327°C
The results of Huy’s eye exam show that he is nearsighted. Which explanation should Huy expect to hear?
“You need convex lenses to shorten the distance that light takes to focus in your eyes.”
“You need concave lenses to shorten the distance that light takes to focus in your eyes.”
“You need convex lenses to lengthen the distance that light takes to focus in your eyes.”
“You need concave lenses to lengthen the distance that light takes to focus in your eyes.” hurrrrrrrrrrry plz
Answers
Answer:
You need concave lenses to lengthen the distance that light takes to focus in your eyes.
Answer:
option D
Explanation:
“You need concave lenses to lengthen the distance that light takes to focus in your eyes.”
2023
The increase in the rate of solvation with a rise in solvent temperature is mainly due to a(n)
a. increase in the activaton energy
b. increase in the movement of molecules leading to more collisions.
c. None of the above
Answers
Which part of the nervous system analyzes the information and initiates a response
Answers
Answer:
CNS (central nervous system)
Explanation:
The central nervous system is responsible for integrating sensory information and responding accordingly.
Neurons (specialized cells of the nervous system ) send signals along thin fibers called axons and communicate with other cells by releasing chemicals called neurotransmitters at cell-cell junctions called synapses.
How long does it take for the earth to rotate
A. 24hrs
B. 1 yr
C. 2 weeks
D. 5 months
Answers
Answer:
24 hrs it takes for the earth to rotate
5 Facts about cell division
Answers
Answer:
Cell division is the process by which a cell, called the parent cell, divides into two cells, called daughter cells.[1] When the cell divides, everything inside it divides also. The nucleus and the chromosomes divide, and the mitochondria divide also.
In mitosis, an ordinary body (somatic) cell divides to make two daughter cells.
In meiosis, a cell divides twice, to produce four gametes (sex cells). The first division of meiosis is a special kind of cell division called a reduction division because the number of chromosomes is halved. The second division of meiosis is similar to mitosis.[2]
Three types of cell division: left is binary fission as in bacteria; right are mitosis and meiosis as in eukaryotes.
Cells are the 'building blocks' of life, and cell division is a basic feature of life. For simple unicellular organisms like Amoebozoa, one cell division reproduces the entire organism. On a larger scale, cell division can create offspring from multicellular organisms, such as plants that grow from cuttings. But most importantly, cell division enables organisms that are able to sexually reproduce to develop from the one-celled fertilised egg (zygote). Cell division also allows for continual renewal and repair of the organism.
The cell division is completed in the four phases prophase, metaphase, anaphase, and telophase.
What is cell division?It is the process by which cells divide into daughter cells. This keeps the cell organism to survive.
The five facts about cell division are:
The cell division has 4 phases.In prophase, the cell DNA condensed to form chromosomes.In metaphase, the chromosomes are aligned in the middle of the cell.In anaphase, the chromosomes move towards the different poles.In telophase cells divide into two daughter cells.Therefore, the cell division is completed in the four phases prophase, metaphase, anaphase, and telophase.
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Gerald's science teacher mixed liquid X and liquid Y, both at room-temperature, in a large beaker. two beakers of clear solutions to the left of a right-pointed arrow, and a large beaker with a clear solution to the right of the arrow The mixture in the large beaker still looked clear like water, but when the students, one at a time, carefully touched the outside of the large beaker, it felt warm to the touch. Why did the large beaker most likely feel warm? A. The two liquids were not soluble in water. B. The release of a gas heated the solution. C. A chemical reaction produced a new substance. D. The energy of mixing warmed the liquids.
Answers
Answer:
c
Explanation:
A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
What is chemical reaction?chemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances.
A chemical reaction is one in which two or more reactants will react to form a new substance. When new substance will form it will produce heat. Therefore, when science teacher was mixing two liquids it was generating heat.
Heating a substance allow molecules to move faster. When heat is given to the object it will move fast. When heat will apply to a solid it will turn into liquid. When heat is supplied to the liquid it will turn into gas.
Therefore, A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
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30g of Aluminum at 80°c is added to 30g of water at 10°c . Predict
the final temperature of the water
Answers
Answer:
the explanation of this 20
Explanation:
20 c
Which substance cannot be separated or broken down into simpler substances by chemical means?
table salt
gold wire
candle wax
water vapor
Answers
Answer: Gold Wire
Explanation:
Out of all of these options only gold wire is an element, elements are pure and cannot be broken down by any chemical means
hope it helped, good luck :)
Balancing chemical equation
_CoBr3 + _CaSO4 -> _CaBr2 + _Co2 (SO4)2
- solution please
Answers
Answer:
2 CoBr3 + 3 CaSO4 = 3 CaBr2 + Co2(SO4)2
Explanation:
Both the appearance and cooking times of food items are affected by the way a piece of food is:
Select one:
a. examined.
b. tenderized.
c. purchased.
d. cut.
Answers
Answer:
D.
cut.
Explanation:
Both the appearance and cooking times of food items are affected by the way a piece of food is cut. Thus option D is correct.
what are the types of food ?
Food has an important role in both culture and cuisine of every country, Different types of food combine to form culinary delights which can bring people together
Food is obtained from both plants and animals where Plants are the primary producers in the food pyramid and all organism directly or indirectly obtain food from plants.
Herbivorous animals get their food from their plant ecosystem where Some animals, obtain food by hunting other animals while others depend on decaying matter of plants and animals which are called decomposers like bacteria, fungi.
Food offers variety forms depend upon climatic conditions and availability and depend on the different factors like Physical determinants ,Biological determinants, Economical determinants.
Thus option D is correct.
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Sooner or later your new school won't feel so strange.get.
Answers
I'm hoping the same for my new coaching classes
This is my first time going out to study ngl-
How do i design a controlled experiment to appropriately test a hypothesis?
Answers
Answer:
you need only one independent variable because if not, you wont know what factors have changed your experiment.
Explanation:
H2SO4 + 2NaOH → Na2SO4 + 2H2O what volume of water vapor will be produced if you start with 71.5 g of sulfuric acid and excess of sodium hydroxide
Answers
Answer:
Explanation:
Find the molar mass of H2SO4
2H = 2 * 1 = 2
S = 1 * 32 =32
O4 = 4*16 = 64
total 98
Find the number of mols in 71.5 grams
mols = given mass / molar mass.
given mass = 71.5
molar mass = 98
mols = 71.5/98
mols = 0.7296 mols of H2SO4
Find the moles of H2O
From the Balanced equation, every mol of H2SO4 produces 2 moles of H2O
mols water = 2 * 0.7296
mols water = 1.4592
That's as far as I can take you. I have to know a great deal more to get the volume of H2O
How many grams is 0.02 moles of CuCl2
Answers
Answer:
2.69g
Explanation:
The molar masses of
Cu = 63.5
Cl = 35.5
So the molar mass of [tex]CuCl_{2}[/tex] is 63.5 + (35.5 x 2) = 134.5
134.5 x 0.02 = 2.69g
Of the following elements aluminum, magnesium, aluminum, silicon, and sodium which has the smallest atomic radius? Explain your answer.
Answers
Answer:
Sodium
Explanation:
Radius grows as you go down and to the right on the ptable.
Substances have a fixed arrangement of atoms. true or false (NO LINKS PLEASE)
Answers
Answer:
True
Explanation:
What are three main ocean currents?
Answers
2. Which of these helps to avoid muscle injuries while exercising?
A:exercising vigorously when muscles are stiff to warm them up
B:slowly and gently stretching muscles before hard exercise
C.pushing through exercise with hurt muscles
D;bursting into hard activity after being still for a while
Answers
Answer:
B
Explanation:
It is important to stretch your muslces as a warm up prior to any exercise.
Answer:
B
Explanation:
What does dalton mean
Answers
Answer:
Meaning:from the valley town; the settlement in the valley. Sounding like the proper English surname it was derived from, Dalton is all about being smart and trendy with equal parts cool and nerdy. Dalton, which comes from “dael” or “valley,” and “tun,” or “settlement,” may have peaked in the 1990s, but that's okay.
Explanation:
a unit used in expressing the molecular weight of proteins, equivalent to atomic mass unit.
Answer:
A unit used in expressing the molecular weight of proteins, equivalent to atomic mass unit.
Or in simpler terms a unit of measure.
Explanation:
Hope this helps and have a great say!!!!