Answer:
Sodium hydroxide is deliquescent (absorbs moisture from the atmosphere) solid. It cannot be weighed accurately. Therefore, it is not possible to prepare a standard solution of sodium hydroxide of accurately known concentration by weighing NaOH.
Scientists often look at how much isotopes of ______
have decayed to help estimate the age
of a fossil or once-living material.
Answer:
If im correct it’s radioisotope
Explanation:
Scientists often look at how much of isotopes of : Carbon-14 have decayed
To determine the age of fossils archeologist make use of the carbon-14 dating ( i.e. making use of naturally occurring radioisotope ¹⁴C ) which is used to determine the age of fossils or material that were once in living on earth.
Carbon has about three (3) isotopes ( Carbon-12, Carbon-13 and Carbon-14 ) .but Carbon-14 isotope is most useful in determining the age of fossils and once-living things
Hence we can conclude that scientists often look at how much of isotopes of Carbon-14 have decayed to help estimate the age of fossils.
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"Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation."
Which statements correctly defend or dispute his conclusion?
A.)He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
B.)He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
D.)He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
Answer:
C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
Explanation:
From the analogy of the problem presented, we can see that Henry is grossly incorrect. His conclusion from the process of the experiment he carried out is completely wrong.
Physical changes are changes that alters the physical properties of matter particularly the form and state.
Chemical changes leads to the formation of a new kind of matter.
We can see that since the salt was obtained back after evaporation, no change has occurred to it.
Therefore, evaporation in itself is a physical change process.
Answer:
c on ed
Explanation:
Oxygen gas is at a temperature of 145 K when it occupies a volume of
1.45 Liters. To what temperature should it be raised to occupy a volume of 6.50
Liters? Show your work. (Express your answer in Kelvin)
Answer:650K
Explanation:
Answer: 650K (1.45/145 = 6.50/x)
Explanation:
What is the volume of 4.78g of O2 gas at STP?
Answer:
Explanation:
The trick here is to realize that if you know the volume of a gas at STP, you can use the fact that
1
mole of any ideal gas occupies
22.7 L
under STP conditions to calculate how many moles of gas you have in your sample.
Under STP conditions:
1 mole of an ideal gas = 22.7 L
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
In your case, you know that your sample of gas occupies
2.28 L
under STP conditions, which are currently defined as a pressure of
100 kPa
and a temperature of
0
∘
C
.
This means that your sample will contain
2.28
L
⋅
molar volume of a gas at STP
1 mole gas
22.7
L
=
0.10044 moles gas
Now, the molar mass of the gas is the mass of exactly
1
mole of the gas. In your case, you know that you get
3.78 g
for every
0.10044
moles, which means that you have
1
mole
⋅
3.78 g
0.10044
moles
=
37.6 g
Since this is the mass of
1
mole of gas, you can say that the molar mass of the gas is
molar mass = 37.6 g mol
−
1
−−−−−−−−−−−−−−−−−−−−−−−
Which of the following is true for an excess reactant?
A) It is the reactant whose atoms remain unbalanced in the equation.
B) It is the reactant that produces a smaller amount of a product.
C) It is the reactant that is left over after the reaction stops.
D) It is the reactant that produces one mole of a product.
Answer:
C) It is the reactant that is left over after the reaction stops.
Explanation:
The excess reactant is the reactant that is left over after the reaction stops. The extent of the reaction is not determined by this reactant.
A limiting reactant is a reactant that is in short supply within a given reaction.
Such reactants determines the extent of chemical reaction.
Limiting reactants are used up in a chemical reaction. The excess reactants remains unchanged after the reaction.Answer: C) It is the reactant that is left over after the reaction stops.
Explanation:
Write your explanation on how plants
nake their own food?
imnortont bynroduct of
Answer:
photosynthesis are ligt water and carbon dioxide
Explanation:
Plants make their own food out of inorganic compounds through a process called photosynthesis that takes place in the leaves. The ingredients necessary for photosynthesis are light, water and carbon dioxide.
You put two pots of water on the stove to boil. Both pots are the same size and are on the same size burner at the same heat setting, and one pot has twice as much
water as the other. Which one will boil faster? Why do you think that is?
Answer:
The emptiest one.
Explanation:
The more water, the more heat molucules have to turn to boil.
Have a great day!
Hope I helped and it would be greatly appreciated if you could be considerate and give brainliest.
80g of calcium reacts with water to form 114g of calcium hydroxide and 2g of
hydrogen.
2 Ca + 2 H0+2CaOH + H,
What mass of water was used in this reaction?
Answer:
31g
Explanation:
80g(Ca)+m(H2O)=114g(CaOH)+2g(H2)
the total mass of the prodicts doesn't change throughout the process
80g+m(H20)=116g
m(H20)=31g
At the end of which era did the dinosaurs became extinct?
Cenozoic
Jurassic
Mesozoic
Paleozoic
Answer:
Cretaceous Period
Explanation:
Dinosaurs went extinct about 65 million years ago (at the end of the Cretaceous Period), after living on Earth for about 165 million years.
How many mols are in 6.73 x 1024 particles of Cu? A. 6.02 x 1023 mols of Cu B. 11.18 mols of Cu C. 1.12 mols of Cu D. 10 mols of Cu\
Answer:
B. 11.18 mols of Cu
Explanation:
Given parameters:
Number of particles in Cu = 6.73 x 10²⁴ particles
Unknown:
Number of moles = ?
Solution:
A mole of a substance is known to contain the Avogadro's number of particles. To solve this problem;
6.02 x 10²³ particles is contained in 1 mole of a substance
6.73 x 10²⁴ particles will be contained in [tex]\frac{6.73 x 10^{24} }{6.02 x 10^{23} }[/tex] = 11.18moles of Cu
Explanation:
Purpose and Theory: A tablet of vitamin C contains the active ingredient called ascorbic acid (HC,H,0.).
Ascorbic acid is an organic acid which is a white power and is soluble in water.
In the following microtitration lab you will be grinding up a vitamin C tablet
, and using a 0.10 g sample of the
vitamin C powder, which will be dissolved in 20-40 mL of water. This solution will be used to determine the
quantity of ascorbic acid in a commercial vitamin C tablet.
Groups
Lab 2
# of Drops 1 or Drops 2 of Drops 3
96
91
94
Hadia
Data & Analysis:
Complete the missing information in the following data table [24]
1
2
3
Trial
Volume of NaOH (drops)
0 05mL drop
(NaOH (O 0050mol/L)
Volume of NaOH (ML)
Average Volume of NaOH (ml)
T I
O 0050
00050
00050
The balanced chemical reaction between ascorbic acid and sodium hydroxide is:
HC,H,O + NaOH NaC,H,Oye H,O,
1. Stoichiometrically calculate the mass (in grams) of ascorbic acid in the powdered sample.
6.900x10^10 ÷ 4.000x10^8
Answer:
1.725e+18
Explanation:
900 mL of water is added to 100 mL of a 0.1 M solution. What is the new concentration?
0.1M
0.001M
0.0001M
0.01M
Answer:
The new concentration of the solution is;
0.01 M
Explanation:
The question relates to concentration of solution and proportion of mixtures
The given parameters are;
The volume of water added to the 0.1 M solution = 900 mL
The initial volume of the solution to which water was added = 100 mL
Therefore, the total final volume of the solution = 100 mL + 900 mL = 1000 mL = 1 L
The concentration of the solution = 0.1 M
The number of moles present in the solution, 'n', is given as follows;
n = 100 mL/(1000 mL) × 0.1 M = 0.01 moles
Given that no more concentrated solution was added, we have;
The number of moles in the 100 mL solution = The number of moles in the 1,000 mL solution
Therefore, the number of moles in the 1,000 mL (1 L) solution = 0.01 moles
Therefore;
The new concentration of the 1,000 mL (1 L) solution = 0.01 moles/(1,000 mL) = 0.01 moles/(1 L) = 0.01 M (By definition of the molarity of a solution)
The new concentration of the 1,000 mL (1 L) solution = 0.01 M.
D. 0.01 M
Given:
The volume of water added to the 0.1 M solution = 900 mL
The initial volume of the solution to which water was added = 100 mL
So,
The total final volume of the solution = 100 mL + 900 mL = 1000 mL = 1 L
The concentration of the solution = 0.1 M
Firstly we need to find the number of moles which is represented by 'n':
[tex]n = \frac{100mL}{1000mL}* 0.1 M\\\\n = 0.01 \text{moles}[/tex]
The number of moles in the 100 mL solution = The number of moles in the 1,000 mL solution
Thus,
The number of moles in the 1,000 mL (1 L) solution = 0.01 moles
For calculation of new concentration:
Using Molarity formula:
The new concentration of the 1,000 mL (1 L) solution [tex]= \frac{0.01\text{ moles}}{1000mL} = \frac{0.01\text{ moles}}{1L} = 0.01 M[/tex]
The new concentration of the 1,000 mL (1 L) solution = 0.01 M.
Thus, the correct option is D.
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help me please asap ...........................................
Which among the following will make lime water look milky?Immersive Reader
(1 Point)
O₂
CaCO₃
Ca(OH)₂
Which among the following will make lime water look milky
option C) Ca(OH)₂
when an ecosystem changes the results are (positive negative both or none) explain
This is science!
Answer:
C. Both
Explanation:
When an Ecosystem changes the effects can be both positive and negative. It all really just depends on what the change is.
!!!!!PLZZZZ HELP!!!!! I'LL GIVE YOU 5 STARS AND A LIKE AND I'LL GIVE YOU POINTS JUST HELP ME ANSWER
Moles|Grams|Liters
1.2 mol N2=__ L
3 mol H2=__ L
0.5 mol CO2=__ L
10.3 L NO2=__ moles
67.2 L SO2=__ moles
89.6 L NO=__ moles
44.8 L NO2=__ grams
201.6 L H2=__ grams
65 grams CO=__ L
152 grams F2=__ L
Answer:
1.2 mol N2 = 26.88 L
3 mol H2 = 67.2 L
0.5 mol CO2 = 11.2 L
10.3 L NO2 = 0.46 moles
67.2 L SO2 = 67.2 / 22.4 = 3 moles
89.6 L NO = 89.6 /22.4 = 4 moles
44.8 L NO2 = 92 grams
201.6 L H2 = 18 g
65 grams CO = 51.9 L
152 grams F2 = 89.6 L
Explanation:
1 mole of a gas occupies a volume of 22.4 L
(N = 14, O = 16, C = 12, H = 1, F = 19)
1.2 mol N2= 1.2 * 22.4 L = 26.88 L
3 mol H2 = 3 * 22.4 L = 67.2 L
0.5 mol CO2 = 0.5 * 22.4 L = 11.2 L
10.3 L NO2 = 10.3 / 22.4 L = 0.46 moles
67.2 L SO2 = 67.2 / 22.4 = 3 moles
89.6 L NO = 89.6 /22.4 = 4 moles
1 mole or 22.4 L of NO₂ has a mass of 46 g
44.8 L NO2 = (44.8 /22.4) * 46 grams = 92 grams
1 mole or 22.4 L of H₂ has a mass of 2 g
201.6 L H2 = (201.6 / 22.4) * 2 grams = 18 g
1 mole or 22.4 L of CO has a mass of 28 g
65 grams CO = 65/28 * 22.4 L = 51.9 L
1 mole of F₂ has a mass of 38 grams
152 grams F2 = 152/38 * 22.4 L = 89.6 L
what is ore of iron
Iron ore are rock rocks
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PLEASE ANSWER 80 POINTS
Which response includes all of the following Z1) LiO2 + CO2 → Li2CO3 Z2) Cl2 + 2 NaBr → Br2 + 2 NaCl Z3) HNO3 + KOH → KNO3 + H2O Z4) SO3 + H2O → H2SO4 that are combination reactions, and none that are not combination reactions? 1. Z1 and Z4 only 2. Another reaction or another combination 3. Z1, Z3 and Z4 only 4. Z1 and Z2 only 5. Z1, Z2 and Z4 only
Answer:
z3 xCo2 + 75 = s01 + h20 = Z2
Explanation:
The study of chemicals is called chemistry.
The correct answer is A.
A combination reaction is defined as the joining of two different elements to form a new compound is called a combination reaction. A new compound is always formed in the reaction.
According to the question, in option A the [tex]Li_2Co_3[/tex] is formed and in reaction 4 [tex]H_2So_4[/tex] is formed.
Hence, the correct option is A that is Z1 and Z4.
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If you could repeat the lab and make it better, what would you do differently and why?
There are always ways that labs can be improved. Now that you are a veteran of this lab and have experience with the procedure, offer some advice to the next scientist about what you suggest and why. Your answer should be at least two to three sentences in length.
Hello, 3Coli Here!
Your Answer is Here:
I would recheck, redo, and revise my answers, if necessary. Also, I can look at the lesson again, if I forgot something. So that's what I would do.
Hopefully, this helps!
Ask your question below!
Answer:
I will just revise and check my answer, or I can redo the lesson.
Explanation:
Have a good day! :D
true or false:
1. chemical bonds have only one form.
2. All compounds are neutral.
3. covalent bonds do not exhibit any sort of preferential charge between atoms.
4. a covalent bond can only involve one shared electron.
How many atoms are in 4.1 grams of zinc?
Answer:
1 mole of zinc has 6.023 x 1023 atoms
So, 4.1 moles will have 4.1 x 6.023 x 1023 atoms = 24.694 x 1023 atoms
Explanation:
Is a cell wall found in a plant cell?
Answer:
A plant cell has a cell wall but an animal cell dosnt have one
Explanation:
Brainliest plz
Explanation:
the cell wall surrounds the plasma membrane of the plant and provides tensile strength and protection against mechanical
As stars get older, before they collapse, they throw off dust, heavy atoms and other materials an form a new
A. Constellation
B. Star
C. Rain cloud
D. Nebula
Answer:
B or D
Explanation:
.....I'm pretty sure I earned on some kids tv show
Can someone help me please but on those two questions
Answer:
In first mcq correct option is "solid" while in 2nd correct is "gas"
Explanation:
Mixtures can be separated by physical processes.
A sequence of physical processes can be used to separate common salt (sodium chloride)
from a mixture containing sand and common salt only.
Give the order and the correct scientific term for the physical processes used to separate the
common salt from the mixture.
don't know sorry.........
how do i caculate the trmperature change that 725 grams of aluminum will undergo when 2.35x10^4 Joules of thermal energy are added to it?
Answer:
36°C
Explanation:
Given parameters:
Mass of aluminum = 725g
Quantity of heat = 2.35 x 10⁴J
Unknown:
Temperature change = ?
Solution:
To solve this problem, we simply use the expression below:
The quantity of energy is given as:
Q = m C Δt
Q is the quantity of energy
m is the mass
C is the specific heat capacity of aluminum = 0.9J/g°C
Δt is the change in temperature
The unknown is Δt;
Δt = [tex]\frac{Q}{mc}[/tex] = [tex]\frac{2.35 x 10^{4} }{725 x 0.9}[/tex] = 36°C
How can you figure out how much energy your body gets from the food you eat and drink in a day?
Answer: So to figure out your energy balance you need to gather some important information. That is, you eat more calories than your body uses. A kilojoule is a calorie) is a measure of energy in food. On average, people eat and drink around 8700 kilojoules a day.
Explanation: I hope that helped- Please mark me as brainliest!
3. A sample of neon gas has a volume of 1.2 L at 28.5°C. What will the volume be at 125°C it the
pressure remains constant?
Answer:
1.58L
Explanation:
Given parameters:
Initial volume = 1.2L
Initial temperature = 28.5°C = 28.5 + 273 = 301.5K
Final temperature = 125°C = 125 + 273 = 398K
Unknown:
New volume = ?
Solution:
Volume and temperature relationship is resolved using the Charles's law.
The law states that "the volume of a fixed mass of a gas varies directly as its absolute temperature if the the pressure is constant".
So;
[tex]\frac{V1}{T1}[/tex] = [tex]\frac{V2}{T2}[/tex]
V1 is the initial volume
T1 is the initial temperature
V2 is the new volume
T2 is the new temperature
[tex]\frac{1.2}{301.5}[/tex] = [tex]\frac{V2}{398}[/tex]
301.5V2 = 477.6
V2 = 1.58L
Balance the following equations:C(s) +CO2(g)- CO(g)
Answer:
C(s)+CO₂(g)→2CO(g)
Explanation:
Basically you’re adding the compounds until they’re equal on both sides
0.385g of 17Cl is how many atoms?
Answer:
(Click here to get an answer to your question ✍️ 0.385g of 17Cl is how many atoms?).
Explanation: