A scientific ________ must have a control, so that the variables that could affect the out come is reduced. A:experiment B:conclusion. C:investigation. D:reasoning
Answer:
A.experiment
Explanation:
hope this helps
Convert 27 degrees Celsius to Kelvin
OOK
300 K
O 27K
327 K
Answer:
300 K
Explanation:
add 273 to change to kelvin
plz mark as brainiest
Which reactant will be used up first if 78.1g of o2 is reacted with 62.4g of c4h10?
A. c4h10
B. o2
C. co2
D. h2o
Answer:
Reagent O₂ will be consumed first.
Explanation:
The balanced reaction between O₂ and C₄H₁₀ is:
2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O
Then, by reaction stoichiometry, the following amounts of reactants and products participate in the reaction:
C₄H₁₀: 2 molesO₂: 13 moles CO₂: 8 moles H₂O: 10 molesBeing:
C: 12 g/moleH: 1 g/moleO: 16 g/moleThe molar mass of the compounds that participate in the reaction is:
C₄H₁₀: 4*12 g/mole + 10*1 g/mole= 58 g/moleO₂: 2*16 g/mole= 32 g/moleCO₂: 12 g/mole + 2*16 g/mole= 44 g/moleH₂O: 2*1 g/mole + 16 g/mole= 18 g/moleThen, by reaction stoichiometry, the following mass quantities of reactants and products participate in the reaction:
C₄H₁₀: 2 moles* 58 g/mole= 116 gO₂: 13 moles* 32 g/mole= 416 gCO₂: 8 moles* 44 g/mole= 352 gH₂O: 10 moles* 18 g/mole= 180 gIf 78.1 g of O₂ react, it is possible to apply the following rule of three: if by stoichiometry 416 g of O₂ react with 116 g of C₄H₁₀, 62.4 g of C₄H₁₀ with how much mass of O₂ do they react?
[tex]mass of O_{2} =\frac{416grams of O_{2}*62.4 grams ofC_{4}H_{10} }{116 grams of C_{4}H_{10}}[/tex]
mass of O₂= 223.78 grams
But 21.78 grams of O₂ are not available, 78.1 grams are available. Since you have less mass than you need to react with 62.4 g of C₄H₁₀, reagent O₂ will be consumed first.
Which of the following are examples of chemical energy being released or stored? (2 points)
A boy eating an orange to survive
A car burning gasoline to move
The sun heating a rock
Select two answers
HELP ME PLS HURRY I NEED THIS ANSWER ASAP !!!!
Answer:
0.1 im pretty sure
because
All those squares equal to 1
So if we use some good ole division
We get 0.1
consider this equation S + 3O₂ → 3O₃ Is this equation balanced? why or why not?
Answer:
This equation is not balanced because you don't have the same amount of each element on each side of the chemical reaction. The balanced equation is:
2 S + 3 ⇒ 2
The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.
Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts.
The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.
By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.
Then, taking into account all of the above, you can determine the amount of elements on each side of the equation:
Left side: 1 sulfur S and 6 oxygen O (coefficient 3 multiplied by sub-index 2)
Right side: 1 sulfur S and 3 oxygen O (subindice value)
As you can see, you have the same amount of sulfur on both sides of the equation but the amount of oxygen is different. This indicates that the chemical equation is not balanced. To balance it, as the amount of sulfur is the same, the amount of oxygen must be balanced, which is different on each side of the reaction.
A simple way is to balance the equation is to multiply the product by 2, that is, add a coefficient 2 in front of the SO3 molecule, the reaction being as follows:
S + 3 ⇒ 2
Now the amount of elements on each side of the equation is:
Left side: 1 sulfur S and 6 oxygen O (coefficient 3 multiplied by subindice 2)
Right side: 2 sulfur S and 6 oxygen O (coefficient 2 multiplied by subindice 3)
The oxygen is now balanced, but the amount of sulfur on both sides of the reaction varies. To balance the quantities of sulfur, as now on the right side you have an amount of 2, you can add the coefficient to sulfur. The chemical equation is as follows:
2 S + 3 ⇒ 2
Now the amount of elements on each side of the equation is:
Left side: 2 sulfur S and 6 oxygen O (coefficient 3 multiplied by subindice 2)
Right side: 2 sulfur S and 6 oxygen O (coefficient 2 multiplied by subindice 3)
Finally you have the same amount of sulfur and oxygen on both sides of the reaction. So the chemical equation is finally balanced.
Explanation:
Brainliest please?
Answer:
it is balenced beacuse both sides have the same ammount of particals
Explanation:
One way to represent a model of an atom is in a drawing. What is another way to show an atomic model?
I think by writing electronic configuration.
Another way of representing an atomic model is the use of periodic table
There are different ways in which an atom can be modelled and some of these methods includes:
The use of the periodic tableThe Bohr- Rutherford modelThe Lewis structure IonsAll the ways listed above can be used to model/represent an atom graphically ( drawing ). while the periodic table can be used to model an atom into its element without drawing. The periodic table makes use of valance numbers of the atoms and chemical similarities between atoms when modeling an atom.
learn more : https://brainly.com/question/19054910
Arrange the events of succession after a volcano erupted in their proper order
Answer:
pioneer species, soil formation, plant growth
Explanation:
The events of succession after a volcano erupted in the proper order include pioneer species being visible. The pioneer species such as algae and Moss are usually found on rocks and dead matter.
After sometime the soil starts to form through weathering activities which then gives rise to and supports the growing of plant species.
1. Which of the following equations is balanced?
a. Al + Br2- 2A1Br3
b. 2Al + 2Br2 → 3AlBr3
c. 2Al + 3Br2 → 2AlBr3
d. Al + Br2 → AlBr3
BRAINLIEST BRAINLIEST
please answer I’m trying to work with 0 hours of sleep :)
2. The heat energy fequired to change a
unit mass of a solid into a liquid at
constant temperature is called
(1) heat of vaporization
(2) heat of formation
(3) heat of solution
(4) heat of fusion
Exactly how many planes contain points J, K, and N?
O 0
O 1
O 2
O 3
Answer:
0
Explanation:
Point J is on neither plane X or plane Y. Hope this helps you.
Answer:
3
Explanation:
Help me ASAP Pls!!!!
Answer:
the answer is the second option
Explanation:
hope you have a great day though!
a local reaction is when a chemical enters the bloodstream? true or false
Answer:
true!
Explanation:
A 100kg sumo wrestler named Bob is doing his daily run. He runs at a velocity of 8m/s. After the run Bob stops for a rest, and sits at the river.
What is Bob's momentum will resting at the river?
Question 10 options:
800 kgm/s
800 kgm/s^s
0 kgm/s
12.5 kgm/s^2
Answer:
0 kgm/s
Explanation:
The momentum of Bob while resting at the river is 0 kgm/s.
This is because the momentum of any object at rest is 0.
Momentum is the quantity of motion a body contains. It is mathematically expressed as;
Momentum = m x v
m is the mass
v is the velocity
So at rest, the velocity of a body is 0m/s and therefore, the momentum is O
Eating around chemicals in the work place is considered safer because today’s chemicals are more diluted than in the past
Pleas e help I will mark brainy
Answer:
D
Explanation:
Hope this helps
Calculate the number of molecules in 895 g of H2O.
Answer:
The number of molecules in 895 g of H₂O is 4.49*10²⁵.
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression. Avogadro's number applies to any substance.
In this case, the molar mass of compound H₂O is 18 g / mol. So if 18 grams of H₂O are present in 1 mole, 895 grams will be present in how many moles of H₂O?
[tex]moles of H_{2}O=\frac{895 grams*1 mole }{18 grams}[/tex]
moles of H₂O= 74.58
Then the following rule of three can be applied: if 1 mole of the compound contains 6.023 * 10²³ molecules by definition of Avogadro's number, 74.58 moles of the compound how many molecules will it contain?
[tex]amount of molecules=\frac{74.58 moles*6.023*10^{23}molecules }{1 mole}[/tex]
amount of molecules=4.49*10²⁵
The number of molecules in 895 g of H₂O is 4.49*10²⁵.
Study this image of the process of photosynthesis. What's wrong with the image? oxygen ohlorpohyll Glucose carbon dioxide water O A Sun rays are shown on the right side of the image. ов. Carbon dioxide is shown as an input. OC. Oxygen is shown as an input. G OD Water is shown as an input.
Answer:
A
Explanation:
The following reaction shows calcium chloride reacting with silver nitrate.
CaCl2 + 2AgNO3 → 2AgCl + Ca(NO3)2
How many grams of Ca(NO3)2 are produced from 2,000.0 grams of AgNO3?
(Molar mass of Ca = 40.1 g/mol, Cl = 35.5 g/mol, O = 16.0 g/mol, Ag = 107.9 g/mol, N = 14.0 g/mol)
(Show your calculations for full credit. Correct answers will only receive partial credit.)
Grams of Ca(NO₃)₂ produced : 0.985 g
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
CaCl₂ + 2AgNO₃ → 2AgCl + Ca(NO₃)₂
MW AgNO₃ : 107.9+14+3.16=169.9
mol AgNO₃ :
[tex]\tt \dfrac{2}{169.9}=0.012[/tex]
mol ratio Ca(NO₃)₂ : AgNO₃ = 1 : 2, so mol Ca(NO₃)₂ :
[tex]\tt \dfrac{1}{2}\times 0.012=0.006[/tex]
MW Ca(NO₃)₂ : 40.1+2.14+6.16=164.1 g/mol
mass Ca(NO₃)₂ :
[tex]\tt 0.006\times 164.1=0.985[/tex]
The
the surface area of the reactants, the faster the reaction rate.
A. greater
B. lesser
Show your work with good use of units, rounding, and significant figures. [Hint: it is good practice to show the value of your answer before you round off to the final answer with the correct significant figures!]
(8 points) How much heat is required to convert 10.00 g of ice at –20.00°C to water at 25°C. The specific heat of ice is 2.09J/g°C; the specific heat of water is 4.182 J/g°C; the heat of fusion is 333.0 J/g.
Group of answer choices
Heat required : 4.8 kJ
Further explanationThe heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C
[tex]\tt Q=10\times 2.09\times (0-(-20)=418~J[/tex]
2. phase change(ice to water)
[tex]\tt Q=10\times 333=3330~J[/tex]
3. heat to raise temperature from 0 °C to 25 °C
[tex]\tt Q=10\times 4.18\times (25-0)=1045~J[/tex]
[tex]\tt Q~tot=418+3330+1045=4793~J\rightarrow rounding~and~2~sig~figs=4.8~kJ[/tex]
How much energy is required to boil 65 grams of 100°C water
And then heat the steam to 150°C?
Answer:
13598 J
Explanation:
Q = m × c × ∆T
Where;
Q = amount of energy (J)
m = mass (grams)
c = specific heat capacity
∆T = change in temperature
m = 65g, specific heat capacity of water = 4.184J/g°C, initial temperature= 100°C, final temperature = 150°C
Q = 65 × 4.184 × (150 - 100)
Q = 271.96 × 50
Q = 13598 J
Hence, 13598 J of energy is required to boil 65 grams of 100°C water and then heat the steam to 150°C.
Agree or disagree
The sun and stars move around earth everyday
ILL MARK BRAINLIEST NEED HELP ASAP
THE OTHER TWO ANSWER CHOICES WERE
20
40
Which of the following characteristics is not necessary an organism to be considered living?
A. All living things grow and develop.
B. All living things move.
C. All living things reproduce.
D. All living things have DNA.
______cells have long projections that help carry electrical messages to other cells.
O striated
O nerve
O smooth
O muscle
Answer: Nerve cells!
its the nerve cell which carry electrical message to others cell.
How many grams are there in 0.75 moles of Sodium
Answer:
44g
Explanation:
What is the density of butane (C4H10) at STP?
Help please
Answer:
his means 1 mole of butane has a volume of 22.4dm3 at STP. 1 mole of butane has the same mass in grams as its relative molecular mass.
Help please and thank you so much
Answer:
A
Explanation:
there cnt be an increase photosynthesis.
surely when its cold,leaves dropped.
How many chlorine aHow many chlorine atoms are there in 4 molecules of CH2Cl2?