Answer:
To convert from moles to atoms, multiply the molar amount by Avogadro's number. To convert from atoms to moles, divide the atom amount by Avogadro's number (or multiply by its reciprocal).
Explanation:
Calculate the molarity of a solution made by dissolving 4.0 g of calcium bromide, CaBr2, in enough water to give 200 mL of solution.
Answer:
0.1 M
Explanation:
Molarity = number of moles / litres of solution.
4 g of calcium bromide = 0.02 mol
(found by dividing 4 g by the atomic mass of CaBr2, which is 199.886)
200 mL of solution = 0.2 litres
Molarity = 0.02 mol / 0.2 L = 0.1 M
Taking into account the definition of molarity, the molarity of the solution is 0.1 [tex]\frac{moles}{L}[/tex].
In first place, you have to know that molarity is a measure of the concentration of that substance and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{L}[/tex].
In this case you know that 4.0 g of calcium bromide, CaBr₂, dissolves in enough water. Then, the molar mass of calcium bromide being 199.8 g/mole, (that is, the mass of one mole of the compound), the number of moles that 4.0 g of the compound contain is calculated as:
amount of moles=4.0 g × [tex]\frac{1 mole}{199.8g}[/tex]
amount of moles= 0.02 moles
And being the volume 200 mL = 0.2 L (being 1000 mL= 1 L), and replacing the values in the definition of molarity, you obtain:
[tex]Molarity=\frac{0.02 moles}{0.2 L}[/tex]
Solving:
Molarity= 0.1 [tex]\frac{moles}{L}[/tex]
In summary, the molarity of the solution is 0.1 [tex]\frac{moles}{L}[/tex].
Learn more about molarity with this example: brainly.com/question/15406534?referrer=searchResults
Why is agar medium used in Petri dishes?
A.It makes bacteria appear larger.
B.It sterilizes the petri dish.
C.It helps microorganisms grow.
D.It makes cells glow.
Answer:
C is the correct answer.
Explanation:
Agar provides a solid growth surface for the bacteria, upon which bacteria reproduce until the distinctive lumps of cells.
The agar medium is used in Petri dishes because it helps microorganisms grow. option C is correct.
What is a microorganism?A microorganism is a microscopic body that cannot be seen with the normal human eyes on anything it can be a virus or bacteria or both. Viruses are disease-causing mostly but there are some good bacteria too.
The use of agar medium is the source of food for the microorganism as all the micronutrients and macronutrients with essential amino acids are present into it.
Therefore, option C is the correct agar medium used in Petri dishes because it helps microorganisms grow.
Learn more about microorganism, here:
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#SPJ2
what is a balanced chemical formula
what is it and how do i do it
Which of these would be called results
Counting fruit flies
Number of fruit flies
Seeing fruit flies on an apple
Wondering why fruit flies are on Apple
(30 POINTS)
Which of the following increases the concentration of OH- ions?
Acid
Base
Water
Salt
Answer:
Acid btw I am new in Brainly
A teacher is instructing students about the states of matter. He wants to compare the
numbers of elements that exist as solids, gases, and liquids at room temperature.
Which kind of illustration should the teacher use to present this information?
The teacher can present this information using a bar chart.
In science, charts are commonly used to present information where comparison is necessary.
Bar charts are especially useful when we intend to show large changes.
In the periodic table, elements exists in various states of matter;
SolidLiquidGasSometimes, as a teacher, you may need to compare the number of elements that exist as solids, gases, and liquids at room temperature.
This comparison is easily brought out using a bar chart since the changes involve large numbers.
Learn more; https://brainly.com/question/18092827
Water molecules tend to be ________ because they are held together by __________ bonds.
cohesive; sulphur
repelant; ionic
adhesive; covalent
cohesive; hydrogen
Suppose a person uses a microscope to look at a cell from the leaf of a tree.
Which structure would they see that would not be found in a cell from a fingernail?
O cilia
O chloroplasts
O ribosomes
O mitochondria
Answer:
Coloroplasts I hope it's right ❤️
How many cg in 173g???
How would you prepare 2.00 L of .100 M K2CrO4
When we are adding water (or solvent) to a solution to decrease its concentration, we are diluting the solution. When dealing with dilution we will use the following equation:
M1 V1 = M2V2
M1 = initial concentration
V1 = initial volume
M2 = final concentration
V2 = final volume
Calculate the volume of the 1.75 M K2CrO4 stock solution needed
M1 = 0.100 M
V1 = 2.00 L
M2 = 1.75 M
V2 = ?
Remember the equation that I said
M1 V1 = M2 V2
[tex]\frac{M1 V1}{M2} = \frac{M2 V2}{M2}[/tex]
V2 = [tex]\frac{M1 V1}{M2}[/tex]
V2 = 0.100*2/1.75
0.114 L
We would prepare 2.00 L of 0.100 M K2CrO4 from 1.75 M K2CrO4 stock solution by diluting 0.114 L of stock solution to the desired volume of 2.00 L
Good Luck!
How many elements are in “H2”
The trachea connects the mouth to the stomach.
True or False?
HEEEEEELLLLLPPPPPPPPPPPPP MEEEEEEEEEEE :(
Answer:
false because trachea connects to the lungs and oesophagus connects from the mouth to the stomach
Answer:
false
Explanation:
It starts with the mouth. The esophagus is a long tube that connects the mouth to the stomach, which is within the ribcage. The stomach is a muscular bag-like structure and forms a J-shaped pouch and is located under the ribcage. The stomach connects to the small intestine.
A material that resists changes in shape and volume would be
A. solid
B. liquid
C. gas
D. plasma
Answer:
solids
Explanation:
solids aren't very malleable of prone to change shape and/or volume so...
A _____ movement tries to improve a part of society, usually through legal methods. a. Reactionary c. Conservative b. Revisionary d. Revolutionary Please select the best answer from the choices provided A B C D
Answer:
B.Revisionary
Explanation:
Revisionary movement usually use legal channels to seek change
A movement that tries to improve a part of society, usually through legal methods is a revisionary movement.
A revisionary movement always target the revision or improvement of the whole or part of the society. Many revisionary movements across the world are calling for different types of social changes such as gender equality and equal access to education.
Hence, a movement that tries to improve a part of society, usually through legal methods is a revisionary movement.
Learn more: https://brainly.com/question/1411414
What process must occur to cause sediment to stick together when forming sedimentary rock?
cooling
cementation
Compaction
weathering
Answer:
Compaction and Cementation
Dissolved minerals in the ground water precipitate (crystallize) from water in the pore spaces forming mineral crusts on the sedimentary grains, gradually cementing the sediments, thus forming a rock
Which of the models shown below best represents the modern understanding of the structure of the atom?
Model B
Model A
Model A
Model C
Photos by Phood and Furman
Model B
ОО
Model C
Answer:
The answer may be A because that's what I believe
Results when a few drops of acidified aqueous potassium manganate are added to potassium iodide
sorry for points ....
hope I helped
need help with 22 and 24
Answer:
22:
Formular:
[tex]atomic \: mass = \frac{ \sum(isotopic \: mass \times \%abundance)}{100} \\ [/tex]
substitute:
[tex]atomic \: mass = \frac{(23.985 \times 78.70) + (24.986 \times 10.13) + (25.983 \times 11.17)}{100} \\ \\ = \frac{(1887.620) + (253.108) + (290.230)}{100} \\ \\ = \frac{2430.958}{100} \\ \\ { \boxed{ \boxed{average \: atomic \: mass = 24.3 \: amu}}}[/tex]
23:
Same element is represented by same number of protons.
Answer:
6 protons. 6 protons
7 neutrons. 8 neutrons
6 electrons. 6 electrons
Note: Atoms with same proton number but different mass number are called isotopes
What happens to elements when they combine together chemically ?
Answer:
When two distinct elements are chemically combined—i.e., chemical bonds form between their atoms—the result is called a chemical compound. Most elements on Earth bond with other elements to form chemical compounds, such as sodium (Na) and Chloride (Cl), which combine to form table salt (NaCl).
which element is more likely to have a strong chemical reaction, magnesium or chlorine?
Answer:
chemical chlorine will have more reaction
What is the scientific notification of 266
A block of metal has a volume of 13.4 in^3 and weighs 5.36 lb.
What is its density in grams per cubic centimeter?
Express the density in grams per cubic centimeter to three significant figures.
Answer:
2.5
Explanation:
13.4 by 5.36
Mass by volume
Answer:
11.1 grams per cubic cm
Explanation:
Volume = 13.4 in^3 = 219.587 cm^3
Mass = 5.36 lb = 2431.255 gram
[tex]density = \frac{mass}{volume} \\ = \frac{2431.255}{219.587} \\ = 11.0719441 \\ \approx \: 11.1 \: grams \: per \: {cm}^{3} [/tex]
Iron can form three different oxides, FeO,Fe2O3 and Fe3O4. A sample of iron oxide was analyzed and was found to contain 69.943% iron with the rest of the mass from oxygen. Determine the empirical formula to determine the identity of the iron oxide
The empirical formula of the iron oxide is [tex]Fe_2O_3[/tex].
And the empirical formula is in an agreement with [tex]Fe_2O_3[/tex] that is iron(III) oxide.
Given:
A sample of iron oxide with 69.943 % of iron and rest with of the mass from oxygen.
To find:
The empirical formula of iron oxide & to identify the type of iron oxide.
Solution:
Consider in 100 grams iron oxide has 69.943 % of iron.
Percentage of oxygen in 100 grams of iron oxide :
= 100% - 69.943%=30.054%
Mass of iron in 100 grams sample =[tex]100g\times \frac{69.943 }{100}=69.943 g[/tex]Mass of oxygen in 100 grams = [tex]100 g\times \frac{30.054}{100}=30.054 g[/tex]Moles of iron = [tex]\frac{69.943 g}{55.845 g/mol}=1.2524mol[/tex]Moles of oxygen = [tex]\frac{30.054 g}{15.999 g/mol}=1.8785 mol[/tex]Let the empirical formula of iron oxide be [tex]Fe_xO_y[/tex]
For empirical formula divide all moles of elements with the least value of moles of an element in the compound:
[tex]x=\frac{1.2524mol}{1.2524mol}=1\\\\y=\frac{1.8785 mol}{1.2524mol}=1.5\\\\Fe_xO_y=Fe_1O_{1.5}\\\\=Fe_{10}O_{15}=Fe_2O_3[/tex]
The empirical formula of the iron oxide is [tex]Fe_2O_3[/tex].
And the empirical formula is in an agreement with [tex]Fe_2O_3[/tex] that is iron(III) oxide.
Learn more about the empirical formula:
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The beaker and the graduated cylinder are both holding liquids. The beaker has lemonade and the cylinder has grapefruit juice. What statement best compares the two liquids?
a tall narrow cylinder and a short wide beaker with one hundred milliliters of yellow liquid in them
A. The mass of the liquid does not change if the volume of the liquid changes.
B. The volumes of the two liquids are exactly the same.
C. The volume of the liquid in the beaker is greater because it is short and round.
D. The volume of the liquid in the graduated cylinder is greater because it is taller and narrower.
Answer:
B
Explanation:
Same amount of liquid and take up same amount of liquid but they are in different containers
If a person weighs 125 lbs, 8 oz., how many mg does s/he weigh?
explanation
Answer:
56925842
Explanation:
its right
Plant Cell
5
F
G
20 points
Which parts are only found in plant cells?
D
А
С
-A
E
m
G
LL
D
B
С
Answer:
it's the chloroplast but I'm not sure which on is it it might be the F.
Please help me!! Really important
Answer:
Lanthanum and Lutetium
I hope this will help you
The boiling point of ethanol is 78.40 c. A student conducts an experiment and finds a boiling point at 75.70 c. What was the percent error? (Please show work I have no idea how to do this cause we haven't learned it yet)
Answer:
[tex]\% \: error = | \frac{origina - expirimental}{original} | \times 100 \\ | \frac{78.40 - 75.70}{78.40} | \times 100 \\ = \frac{2.7}{78.4} \times 100 \\ =3.44 \\ thank \: you[/tex]
When a substance is in the process of changing phases states of matter what happens to the temperature
Answer:
Temperature stays constant.
Explanation:
During a phase change, the temperature does not change. Temperature will only change when a phase change is completed.
what's is half life
