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
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!
Are cyclops heterotrophic or autotrophic?
Cyclops are heterotrophic
Where is type of precipitation is most likely to form during a thunderstorm
Answer:
hail, btw have a nice day
Answer:
Hail
Explanation:
I got it right on my test
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
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What element has the following electron configuration? 1s 22s 22p 63s 23p 64s 2
Answer:
answer is 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
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
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]
When mixing an acid with water, which of the following must always be done?
A.
Never mix an acid with water, it will explode.
B.
Always add the acid to the water slowly, taking a moment to stir between drops.
C.
Always heat the acid before mixing with water.
D.
Always shake both solutions before mixing.
Answer:
B
Explanation:
Answer:
B. Always add the acid to the water slowly, taking a moment to stir between drops
Which one will diffuse faster Ammonia or carbon dioxide Why?
jcp-fnoa-kzk join here
What is the definition of a community in environmental science
it is sunny today is that whether or climate this isn't chemistry but...
Answer:
weather
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:
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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.
The density of ice at its freezing point is 0.917 g/cm3. What is the mass of 2.5 cm3 of ice at this temperature?
A. 1.6 g
B. 2.3 g
C.2.7 g
D.3.4 g
Answer:
The answer is option BExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 0.917 × 2.5 = 2.2925
We have the final answer as
2.3 gHope this helps you
Answer:. 2.3 g
Explanation:
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
Strontium-90 is one of the products of the fission of uranium-235. This strontium isotope is radioactive, with a half-life of 28.1 yr. Calculate how long it will take for 0.900 g of the isotope to be reduced to 0.170 g by decay.
Answer:
67.6 years is the time the isotope take to decay from 0.900g to 0.170g
Explanation:
The radioactive decay follows first order law:
Ln [A] = -kt + ln[A]₀
Where [A] is concentration after time t,
k is decay constant:
k = ln 2 / t(1/2)
k = ln2 / 28.1 years
k = 0.02467 years⁻¹
[A]₀ = Initial concentration.
We can replace concentration and use the mass of the isotope:
Ln [A] = -kt + ln[A]₀
Ln [0.170g] = -0.02467 years⁻¹t + ln[0.900g]
-1.667 = -0.02467 years⁻¹t
t =
67.6 years is the time the isotope take to decay from 0.900g to 0.170gThe time required for the sample to reduce to 0.170 grams has been 67.75 years.
Half-life can be defined as the times required by the substance to reduce to half of its initial concentration.
The half-life can be expressed as:
Amount left = Initial amount [tex]\times[/tex] [tex]\rm \dfrac{1}{2}^\dfrac{time}{Half-life}[/tex]
From the given:
0.17 g = 0.9 [tex]\rm \times\;\dfrac{1}{2}^\dfrac{t}{28.1}[/tex]
[tex]\rm \dfrac{0.17}{0.9}[/tex] = [tex]\rm \dfrac{1}{2}^\dfrac{t}{28.1}[/tex]
0.188 = [tex]\rm (0.5)^\dfrac{t}{28.1}[/tex]
Taking log on both the sides,
log 0.188 = [tex]\rm \dfrac{t}{28.1}\;\times[/tex] log 0.5
2.411 = [tex]\rm\dfrac{t}{28.1}[/tex]
t = 2.411 [tex]\times[/tex] 28.1 years
Time = 67.75 years.
The time required for the sample to reduce to 0.170 grams has been 67.75 years.
For more information about half-life, refer to the link:
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hi can someone help me with these 2 :)
Answer:
a and d
Explanation:
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
Fill in the coefficients that will balance the following reaction:
(Note: Use 1 as coefficient where appropriate.)
_C3H7OH + _O2 → _CO2 + _H2O
Question 2 (1 point) The chemical formula for an ionic compound represents the a b number of ions in each molecule. total number of ions in the crystal lattice. number of atoms in each molecule simplest ratio of ions that results in an electrically neutral compound.
The chemical formula for an ionic compound represents the simplest ratio of ions that results in an electrically neutral compound. That is option D.
What is an ionic chemical compound?An ionic chemical compound is defined as the type of chemical compound that contains both the oppositely-charged ions of a metal and a nonmetal are attracted reacting with each other to form an ionic bond.
When represented as a chemical formula, it is the simplest ratio of ions that results in an electrically neutral compound.
Learn more about ionic compound here:
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A neutral atom of gold has the same number of electrons and what?
Marissa blows up balloons for a party. She decides how big or small to make each balloon. Why does the air she blows into each balloon take up all the space inside the balloon
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:
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!
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)
What is the independent variable when testing to see how the viscosity of a liquid affects its flow rate
Answer:
Viscosity
Explanation:
The viscosity of the liquid is the independent variable. The flow rate is the dependent variable in this hypothesis.
The statement given is called the hypothesis. It is a form of scientific guess into a phenomenon.
An independent variable is the cause. A dependent variable is the effect produced. In this hypothesis, the cause of the various flow rate of the liquid is the viscosity. It is therefore the independent variable. The flow rate is the dependent variable.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.A student used the Dumas method to determine the molar mass of a volatile material. They placed the container into the ice bath BEFORE all of the material was vaporized. What will happen to their final calculations?
A. The Molar Mass will be too low.
B. The Molar Mass will not be effected.
C. The Molar Mass will be too high.
Answer: the molar mass will be too high
Explanation: