Answer:
a chemical change is usually an irreversible chemical reaction. an example of this is rusting.
a physical change is usually visible while a chemical change isn't. also, a chemical change is irreversible while a physical change is.
Explanation:
Students measuring the mass of a metal block record 2.985 g, 3.051 g, 3.102
g, and 3.211 g. Which other measurement of the block's mass would be most
precise?
A. 2.804 g
B. 3.1159
C. 3.418 g
D. 3.509 g
Answer:C - 3.115 g
Explanation:Correct
A 25.00 ml solution containing 0.033 M sodium acetate is titrated with a 0.098 M solution of HCl. How mar
milliliters of HCl are required to reach the endpoint?
Answer:
[tex]8.42\ \text{mL}[/tex]
Explanation:
When the endpoint is reached the millimoles of sodium acetate and HCl will be equal.
[tex]\text{Volume of sodium acetate}=25\ \text{mL}[/tex]
[tex]\text{Molarity of sodium acetate}=0.033M[/tex]
[tex]\text{Molarity of HCl}=0.098M[/tex]
[tex]\text{Millimoles of sodium acetate}=25\times 0.033=0.825\ \text{mmol}[/tex]
Let [tex]V=\text{Volume of HCl}[/tex]
[tex]\text{Millimoles of HCl}=0.098V[/tex]
At end point the millimoles will be equal to that of sodium acetate
[tex]0.825=0.098V\\\Rightarrow V=\dfrac{0.825}{0.098}\\\Rightarrow V=8.42\ \text{mL}[/tex]
The volume of HCl required is [tex]8.42\ \text{mL}[/tex].
The volume of HCl required to required to reach endpoint is 8.42 mL
From the question,
We are to determine the volume of HCl required to reach endpoint
First, we will write a balanced chemical equation for the reaction.
The balanced chemical equation for the reaction is
CH₃COONa + HCl → CH₃COOH + NaCl
This means
1 mole of sodium acetate is required to completely neutralize 1 mole of HCl
Now, we will determine the number of moles of sodium acetate present
Using the formula
Number of moles = Concentration × Volume
Concentration of sodium acetate = 0.033 M
Volume of sodium acetate = 25.00 mL = 0.025 L
∴ Number of moles of sodium acetate present = 0.033 × 0.025
Number of moles of sodium acetate present = 0.000825 mole
Now,
Since, 1 mole of sodium acetate is required to completely neutralize 1 mole of HCl
Then,
0.000825 mole of sodium acetate would be required to completely neutralize 0.000825 mole of HCl
∴ The number of moles of HCl needed is 0.000825 mole
Now, for the volume of 0.098 M HCl required to reach endpoint
Using the formula
[tex]Volume = \frac{Number\ of\ moles}{Concentration}[/tex]
∴ Volume of HCl required to required to reach endpoint = [tex]\frac{0.000825}{0.098}[/tex]
Volume of HCl required to required to reach endpoint = 0.008418367 L
Volume of HCl required to required to reach endpoint = 8.418367 mL
Volume of HCl required to required to reach endpoint ≅ 8.42 mL
Hence, the volume of HCl required to required to reach endpoint is 8.42 mL
Learn more here: https://brainly.com/question/9698827
Whats faster light or sound? PLEASE HELPY ME
Answer:
The answer is that light is faster than sound.
Explanation:
A good example is of lightning and thunder during a thunderstorm.
mark me brainliest!
Why do we dream? Help me Please;)
Answer:
Explanation:
we dream because when our bodies are taking memories into long term, the memories from that day or the day before collide and make dreams. that is why they resemble things that have happened to us.
Answer:
One widely held theory about the purpose of dreams is that they help you store important memories and things you've learned, get rid of unimportant memories, and sort through complicated thoughts and feelings. Research shows that sleep helps store memories.
The brain is so active when we dream that it is virtually indistinguishable from a brain in the waking state. Even so, the chemistry of it is entirely rewired when we sleep. Many scientists attribute this to the reason dreams are so strange and bizarre.
Explanation:
The combination of all the organ systems working together make up a(n) _______________________.
1.organ system
2.organism
3.organ
4.cell
Answer:
2
Explanation:
Uranium-235 undergoes the following fission process after
absorbing a neutron:
235 U +in+Kr + 14 Ba + xon
What is the value of x?
x =
Your answer should be a number.
The value of x = 3
Further explanationFusion and fission reactions are reactions involving atomic nucleus reactions
Fission reaction is a nucleation division reaction by firing a particle usually neutron so that it gets smaller particles of atomic nuclei.
Fission of Uranium-235
[tex]\tt ^1_0n+^{235}_{92}U\rightarrow ^{141}_{56}Ba+^{92}_{36}Kr+3^1_0n[/tex]
In this reaction, the sum of the mass number and atomic number of the elements involved in the reaction will be equal
atomic number left : 0+92=92
atomic number right : 56+36=92
mass number left : 1+235=236
mass number right : 141+92+3=236
The value of x in the fission process of uranium has been 3.
Fission reaction has been the nuclear reaction resulting in the breaking of the element into smaller substituents. The fission of uranium has been:
n + U [tex]\rightarrow[/tex] Ba + Kr + n
In the given fission reaction, the mass number of the atoms on the right and left of the reaction has to be equal. The mass number has been;
235 + 1 = 141 + 92 + x
236 = 233 + x
x = 236 -233
x = 3
The value of x in the fission process of uranium has been 3.
For more information about the fission process, refer to the link:
https://brainly.com/question/16196953
WILL MARK BRAINLIEST-
what is the lewis dot structure of CH2OH and N2O4
Identify ALL the possible mol ratio from
this balanced equation:
Answer:
[tex]\frac{1 mole of N_{2} }{3 moles of H_{2} }[/tex]
Explanation:
The equation of the reaction:
Nitrogen gas N₂ reacts with Hydrogen as H₂ to produce ammonia NH₃;
N₂ + H₂ → NH₃
The balanced equation is ;
N₂ + 3H₂ → 2NH₃
The mole ratio is the ratio of the coefficients of the combining reactants;
1 mole of N₂ combines with 3 mole of H₂;
So;
[tex]\frac{1 mole of N_{2} }{3 moles of H_{2} }[/tex]
1. The behavior that occurs when a wave bends as it changes media is known as
a) absorption
b) refraction.
c) reflection
d) transmission
Answer:
b refraction
Explanation:
i saw on nasa's website lol
If the 50 kg object slows down to have a velocity of 1 m/s, how much kinetic energy does it have ?
Answer:25J
Explanation: KE:1/2mv^2=KE=25x1=25J
What is the oxidation number of an element? PLz help. Will give brainliest to correct answer. explanation helpful but not required. Dont answer unless you know
Answer:
its eathe a or c a 50/50 chance
Answer:
Explanation:
its B
(please mark as brainliest if it's correct)
ANSWER THIS TO BE MARKED BRAINILEST Water in a beaker measures 250 milliliters. A rock is completely submerged in the water. The water level now reads 375 milliliters. What is the volume of the rock in cubic centimeters? Explain your answer
Answer:
125 cubic meters
Explanation:
Subtract 375-250=125 cubic meters
Are cyclops heterotrophic or autotrophic?
Cyclops are heterotrophic
What is the independent variable based on the hypothesis below?
"If acid rain is in water, then fish populations will increase"
Answer:
Acid rain
Explanation:
The independent variable in the hypothesis statement is the acid rain. An independent variable is usually the cause in an experiment.
This variable give rises to the effects observed as the dependent variable.
In the presence of the acid rain, the fish population will increase.
The dependent variable is the fish population or number of fishes.
The independent variable is the acid rain as it is the cause of the effect observed on the fish population.
it is sunny today is that whether or climate this isn't chemistry but...
Answer:
weather
Explanation:
Fill in the coefficients that will balance the following reaction:
(Note: Use 1 as coefficient where appropriate.)
_C3H7OH + _O2 → _CO2 + _H2O
Group 17 is called the halogen family, and the group to its right is called the noble gases. How are these elements alike and how are they different?
Explanation:
The halogen family and noble gases are similar in just one particular way, they are groups of non-metals. All members of these two groups are categorized as non-metals.
Here are some of the differences between them;
Halogens have 7 electrons in their outermost shell whereas noble gases have 8 electrons in theirs. Halogens are highly reactive elements, noble gases are non-reactive. Halogens are made up of electronegative elements where as noble gases are neither electropositive nor electronegative.hi can someone help me with these 2 :)
Answer:
a and d
Explanation:
can someone please help me i don't know these question bc my family celebrates thanksgiving differently. plz and thank you :3
Easy: How many turkeys are consumed on Thanksgiving day in America?
Medium: How long did the first Thanksgiving Celebration last?
Hard: When was the first NFL football game on Thanksgiving?
Fun: Who was the first president to pardon a turkey?
Answer:
Easy 46 million turkeys
Medium three days
Hard: 1934
Fun: The first President on record issuing a "pardon" to his turkey was Ronald Reagan.
Explanation:
hop tis helped
What happens when the atoms of a substance are regrouped
Fill in the coefficients that will balance the following reaction:
(Note: Use 1 as coefficient where appropriate.)
CH4 +
O2 →
CO2 +
H2O
Answer:
CH4 + 2 O2 → CO2 + 2 H2O
Explanation:
There are one mole of O2 on the left side and on the right side there are three moles of O2. And to fix it you would need to make it two moles of O2 to have four molecules of O2 on the left side. Then you would make two moles of H2O to have a total of four moles of O2 on the right. Therefore, CH4 + 2 O2 → CO2 + 2 H2O is the answer.
Answer:
1,2,1,2
Explanation:
hope this helped!
This water bottle has a mass of 0.5 kg.
CU
If the net force acting on the bottle is 5 N to the right, what is the bottle's
acceleration?
(Hint: Use the formula a = =)
A. a = 10 m/s2 left
B. a = 50 m/s2 right
c. a = 10 m/s2 right
D. a = 2 m/s2 left
PLEASE ANSWER I WILL GIVE BRAINLYEST
Answer: the answer is a=10m/s^2 right
Explanation: it just make more since then the other answers .
Answer:
c 10
Explanation:
ape.x verified
A reddish layer of rust can form on old iron nails and bikes. In this chemical reaction, iron reacts slowly with oxygen in the air. The chemical name for rust is iron oxide. What are the reactant(s) and product(s) of this reaction? Write down the equation, in words, for the formation of rust.
Answer:
Iron slowly reacts with oxygen and forms rust. In this case, the reactants are iron and oxygen. The product is rust, or iron oxide. The chemical equation looks like this:
Explanation:
iron + oxygen → iron oxide
Answer:
Iron slowly reacts with oxygen and forms rust. In this case, the reactants are iron and oxygen. The product is rust, or iron oxide. The chemical equation looks like this:
iron + oxygen → iron oxide
Explanation:
This was the answer straight from Plato. I hope that this helped you, please mark me the brainiest, like and rate my answer if it did! :)
As a 7 inch candle burns down, its height decreases 1/2 inch each hour. How many hours does it take for the candle to burn completely?
Answer:
14
Explanation:
Answer:
As a 7-inch candle burns down, its height decreases 1/2 inch each hour. How many hours does it take for the candle to burn completely?
Explanation:
It would be 14 because the candle is 7 inches and it loses 1/2 inch each hour.
read the instructions and answer
Answer:
laughing this question is a joke I think at first .
Explanation:
there are many mistakes : electrons are revolving in shell or orbits around the nucleus.
first shell always has two electron
after first shell , all shells contains eight electrons
electron have negative charge
proton have positive charge
nucleus have no charge
atom is neutral becoz the + charge of proton. and - charge of electron cancel each other's effect and atom is stable and neutral
Explain how the forces involved in a car crash could lead to multiple cars coming to a complete stop. Use information from the article in order to answer this question. You should be answering in at least 2 complete sentences.
Answer:
Newton's First Law...
Explanation:
The only force that acts on the car is the sudden deceleration from v to 0 velocity in a brief period of time, due to the collision with another object. However, when viewing the total system, the collision in the situation with two cars releases twice as much energy as the collision with a wall
When the following equation is balanced, the coefficients are __________. Al(NO3)3 + Na2S → Al2S3 + Na(NO3)
The balanced coefficients in the reaction are now; 2, 3, 1, 3.
A balanced chemical reaction equation is one in which the number of atoms of each element on the right hand side of the reaction equation is equal to the number of atoms of the same element on the left hand side of the reaction equation.
For the reaction show, the balanced reaction equation is; 2Al(NO3)3 + 3Na2S → Al2S3 +3 Na(NO3). The balanced coefficients in the reaction are now; 2, 3, 1, 3.
Learn more about reaction equations: https://brainly.com/question/15939621
How do you differentiate a neutral solution like water and a strong acid solution like battery acid?
Answer:
If the pH of a solution is less than 7, the solution is called acidic; if the pH is about 7, the solution is neutral; if the pH is greater than 7, the solution is is called basic. In an acidic solution, then, the concentration of hydrogen ions is greater than the concentration of hydroxide ions.
Explanation:
Not sure about the context of the question, but you can check with a ph scale tester.
Volcanic island acres are associated with which type of plate boundary
anyone who knows the account antonio716 add me bc this is my new account
Answer:
nope
Explanation:
your not my friend yet but you still can friend me
may your day be blessed and happy