Answer:
A, 4Fe 3O2 → 2Fe2O3
How many molecules are present in 98.2g of NaNO3
6.96 × 10²³ molecules NaNO₃
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
98.2 g NaNO₃
Step 2: Identify Conversions
Avogadro's Number
Molar Mass of Na - 22.99 g/mol
Molar Mass of N - 14.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of NaNO₃ - 22.99 + 14.01 + 3(16.00) = 85.00 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 98.2 \ g \ NaNO_3(\frac{1 \ mol \ NaNO_3}{85.00 \ g \ NaNO_3})(\frac{6.022 \cdot 10^{23} \ molecules \ NaNO_3}{1 \ mol \ NaNO_3})[/tex]Multiply: [tex]\displaystyle 6.95718 \cdot 10^{23} \ molecules \ NaNO_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
6.95718 × 10²³ molecules NaNO₃ ≈ 6.96 × 10²³ molecules NaNO₃
When a nitrogen atom covalently bonds to three hydrogen atoms to form ammonia, it still retains one pair of unshared electrons.
According to VSEPR theory, what is the shape of an ammonia molecule?
OA. linear triatomic
OB. tetrahedral
OC
pyramidal
OD. trigonal planar
Answer:
C. Trigonal pyramidal
Explanation:
According to the valence shell electron pair repulsion theory, the shape of ammonia is trigonal pyramidal in nature.
The bond angle is 107° and it has bond pair of 3 and lone pair of 1.
The variations in the bond angles of molecules can be explained by the VSEPR model. This model determines the total number of electron pairs surrounding the central atom of a specie.A tetrahedral is exhibited by methane
Trigonal planar is exhibited by BF₃
Lisa wants to determine which melts faster, an ice cube or a popsicle. What procedure should she follow to conduct her experiment?
A.
Set an ice cube equal in size to a popsicle at room temperature, and time how long it takes each to melt.
B.
Set an ice cube and a chocolate popsicle at room temperature, and time how long it takes each to melt.
C.
Set any ice cube and any popsicle at room temperature, and time how long it takes each to melt.
D.
Set an ice cube and an orange popsicle at room temperature, and time how long it takes each to melt.
Elephant heart cells have 56 chromosomes. Elephant egg cells have
28 chromosomes
112 chromosomes
56 chromosomes
16 chromosomes
Answer:
28 chromosomes
Explanation:
The elephant egg cells will have just half of the original number of chromosomes which is 28 chromosomes.
The other zygote which is the male sperm will also contain 28 chromosomes.
Reproductive cells the egg and the sperm contains a haploid number of cells. During fertilization the cells combine to form a complete diploid where both the male and female genetic material are replicated. This way half of the original chromosome number are taken through to the sex cells.
It snows one inch of snow. Snow is ice. There is now 1 inch of snow on your car and 1 inch of snow on your wooden deck. The sun comes out and all the snow begins to melt. Which melts first? [Assume both get equal amounts of sunlight] *
How many grams of oxygen, O2, required for the complete combustion of 36 grams of pentane, C5H12 at standard conditions?
C5H12 + 8O2 -> 5Co2 + 6 H2O
Answer:
128 grams of oxygen, O₂, is required for the complete combustion of 36 grams of pentane, C₅H₁₂ under standard conditions.
Explanation:
The balanced reaction is:
C₅H₁₂ + 8 O₂ ⇒ 5 CO₂ + 6 H₂O
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
C₅H₁₂: 1 moleO₂: 8 molesCO₂: 5 molesH₂O: 6 molesBeing the molar masses of the compounds:
C₅H₁₂: 72 g/moleO₂: 32 g/moleCO₂: 44 g/moleH₂O: 18 g/molethen, by stoichiometry, the following quantities of mass participate in the reaction:
C₅H₁₂: 1 mole* 72 g/mole= 72 gO₂: 8 moles* 32 g/mole= 256 gCO₂: 5 moles* 44 g/mole= 220 gH₂O: 6 moles* 18 g/mole= 108 gThen you can apply the following rule of three: if by stoichiometry 72 grams of pentane react with 256 grams of oxygen, then 36 grams of pentane with how much mass of oxygen does it react?
[tex]mass of oxygen=\frac{36 grams of pentane*256 grams of oxygen}{72 grams of pentane}[/tex]
mass of oxygen= 128 grams
128 grams of oxygen, O₂, is required for the complete combustion of 36 grams of pentane, C₅H₁₂ under standard conditions.
Answer:
128 grams of oxygen, O₂, is required for the complete combustion of 36 grams of pentane, C₅H₁₂ under standard conditions.
Explanation:
Did the work trust!
true it false: Liquid molecules have more room to slide past one another which ls why they can easily change shape
Answer:
[tex] \huge \boxed{TRUE}[/tex]
Explanation:
Liquid molecules have more room to slide past one another which is why they can easily change shape.
From the following list of symbols, choose two elements that would likely form a
molecular compound. Explain your choice.
Mg:
S:
K:
O:
Help plzz
Answer:
O ( Oxygen )
because oxygen atom is a non metal and highly electronegative which reacts by itself to form a di-molecular compound of Oxygen
[tex]O _{2}[/tex]
What happens to sound waves when you are moving toward the source of the
sound?
A. Wavelength increases.
B. Wave speed decreases.
C. Amplitude decreases.
D. Frequency increases.
Answer:
B
Explanation:
5.6 x 10^3 cm = ___cg
Answer:
560000 cg
Explanation:
5.6 x 10^3 = 5600
1 g = 100 cg
5600 g = 560000 cg
Density is defined as mass per unit volume, or D = m/v. Solve the density
equation for the variable v: *
v = D + m
v = D/m
v = D * m
v= m/D
Answer:
v = m/D
Explanation:
Density is defined as the mass per unit volume, or D = m/v. Solve for Density equation for the variable v:
With this we are making v Which represents volume the subject so;
[tex]d = \frac{m}{v} [/tex]
With this you multiply both sides by ;
[tex]v[/tex]
[tex]v(d) = ( \frac{m}{v})v[/tex]
And then the v will multiply the d making it
“vd” and the ‘v’ will cancel the v making it;
[tex]vd = m[/tex]
So then we divide both sides by d to make v the subject.
[tex] \frac{vd}{d} = \frac{m}{d} [/tex]
So the d cancels the d leaving;
[tex]v = \frac{m}{d} [/tex]
The diagram shows a homemade car being pushed with a force of 25 N. The force causes the car to move at a constant speed of 3 m/s2. What will happen if the force is changed to 35 N?
Answer:
The acceleration of the car will increase drastically
Explanation:
Based on newtons second law of motion, the force applied on a body is directly proportional to the product of its mass and acceleration;
Force = mass x acceleration
Since the mass of the car is constant, an increase in force will cause an increase in acceleration.
A decrease in the force will impact a lesser acceleration on the motor car.
This way, the change in velocity of the body per unit of time will increase drastically.
A scientist named J. J. Thomson developed a model of the atom in which electrons are spread throughout a cloud of positive charge. Which discovery directly caused scientists to revise this model?
Answer:
A small mass of positive charge was discovered in the center of the atom.
Explanation:
Atoms is the combination of protons, neutrons, as well as electrons particles. The particles that are in the centre of atom is Protons and neutrons, which made up the nucleus, this nucleus is surrounded by electron.
The discovery that directly caused scientists to revise this model of the atom is that A small mass of positive charge known as proton, and a positive charge particle was discovered by Ernest Rutherford, in the center of the atom in the year 1900. Ernest Rutherford through his research resulted to splitting of the atom during nuclear reaction and proton was discovered.
similar scientific themes are seen in what areas of science?
A. only in areas dealing with living things
B. in all areas of science
C. only in areas dealing with tinny particles
D. only in areas dealing with things on Earth
Answer:B
Explanation:
What action is the best example of a direct observation
Answer:
The best example of direct observation is when the researcher of animal behavior directly observe how animal lives in a reservation.
the relative atomic mass of hydrogen is Ar (H) = 1008.Calculate the absolute mass of a hydrogen atom
Answer:
im good but mark brainliest
Explanation:
Answer:
i don think thats what she ment
Explanation:
Which of the following is a characteristic of reliable scientific study? (5
points)
Answer:I need the options
Explanation:
1. The forks shown are made of silver (Ag). Some of the silver forks
shown have lost their luster—they have become tarnished. This is an
example of Type here.
Pleasee help
Answer:
Corrosion
Explanation:
Silver is known as a noble metal. Noble metals are those metals that are resistant to corrosion.
However, we can not say that silver is completely resistant to corrosion because silver can corrode when exposed to air and sulphur.
Exposure to air and sulphur leads to the coating of the silver with a sulphide layer thereby making the metal to become tarnished and loose its metallic luster.
25 cm3 of 0.2 mol / dm3 sodium hydroxide (NaOH) neutralises 10 cm3 of dilute sulfuric
acid (H2SO4). What is the concentration of the sulfuric acid?
Answer:
too simple question i don't have book pen now otherwise solved it
Select the correct answer. Which statement best describes how chemical equations demonstrate conservation of mass? OA The number of reactants is the same as the number of products. B. The compounds are the same on each side of the reaction. OC. The number of atoms of each element is the same on each side of the equation. OD. The state of matter is the same on each side of the equation.
Answer: C. The number of atoms of each element is the same on each side of the equation.
Explanation:
The Law of Conservation of Matter shows that it is not possible for matter to either be created nor for it to be destroyed so the number of atoms of each element on the reactant side of the equation must equal the number of atoms in each element on the product side of the equation.
This is why the following equation is incomplete:
H₂ + O₂ ⇒ H₂O
The oxygen atoms are not the same on either side.
Equation will therefor have to be balanced which will make it:
2H₂ + O₂ ⇒ 2H₂O
Notice now that atoms are the same on both sides.
Why are bubbles and color changes not always chemical change?
What is indicated by a letter in parentheses after a chemical
formula, such as (s)?
a) whether the reaction is fast or slow
b) the purity of the substance
c) the physical state of the substance
d) that the substance is a catalyst
The letter in parentheses after a chemical formula indicates c) the physical state of the substance.
The letters can be:
→ (s) for solid.
→ (l) for liquid.
→ (g) for gazeous.
→ (aq) for an aqueous solution (like NaCl (aq) - NaCl is dissolved in water)
True or false. The center of gravity and center of mass of an object need to be in the same spot?
Answer:
True................
Answer:
true
Explanation:
Which element has 7 valence electrons and 3 electron shells?
Chemistry Conversion: Convert 3.0099 dumps to wigs. 6375.23 dumps = 1 wig Round your answer to 5 sig figs. dumps and wigs is not a real unit just used for example.
Answer:
There are 0.00047212 wig in 3.0099 dumps.
Explanation:
In this problem, we need to convert 3.0099 dumps to wigs.
6375.23 dumps = 1 wig (given)
1 dump = (1/6375.23) wig
To convert 3.0099 dumps to wigs, multiply 3.0099 by (1/6375.23).
3.0099 dumps = [tex]\dfrac{1}{6375.23}\cdot3.0099[/tex]
= 0.00047 wig
Hence, there are 0.00047212 wig in 3.0099 dumps.
15 grams of hydrogen and 7.5 grams of oxygen were placed in a beaker. An explosion happened inside the baker that produced water. The beaker was never opened. How many grams of water were produced?
Answer:
16.8768 g
Explanation:
The reaction that takes place is:
2H₂ + O₂ → 2H₂OFirst we convert the mass of hydrogen and oxygen into moles, using their respective molar masses:
H ⇒ 15 g ÷ 1 g/mol = 15 mol HO ⇒ 7.5 g ÷ 16 g/mol = 0.4688 mol OThere are significantly less oxygen moles than hydrogen moles, so oxygen is the limiting reactant.
We calculate the produced moles of water, using the moles of the limiting reactant:
0.4688 mol O * [tex]\frac{2molH_2O}{1molO_2}[/tex] = 0.9376 mol H₂OFinally we convert water moles into grams, using its molar mass:
0.9376 mol H₂O * 18 g/mol = 16.8768 gBesides surface area
and rock composition,
what is the third main
factor in determining
how rock is affected
by weathering?
A weight
B. color
C Climate
D. density
Answer:
A
Explanation:
Besides surface area and rock composition, the climate is the third main factor in determining how rock is affected by weathering. Therefore, option (C) is correct.
What is weathering?Weathering can be described as the deterioration of rocks, soils, and minerals through contact with water, gases, and biological organisms. Weathering takes place in situ and is distinct from erosion, which includes the transport of rocks and minerals by agents such as snow, water, ice, wind, waves, and gravity.
Weathering is divided into physical weathering and chemical weathering. Physical weathering includes the breakdown of rocks and soils through the mechanical effects of ice, heat, water, or other agents.
Chemical weathering includes the chemical reaction of water, gases, and biologically formed chemicals with rocks and soils. The materials left after the rock breaks combine with organic matter to form soil.
Many landforms and landscapes on the surface of the earth are the results of weathering processes.
Learn more about weathering, here:
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what is the realationship between chemicals and cancer
Answer:
Explanation:
"An early link between cancer and a chemical was found in the late 1700s. An English physician noted that a large number of chimney sweeps had cancer of the scrotum due to exposure to soot, which contains chemicals known as polycyclic aromatic hydrocarbons. Since then, many more chemicals have been identified as known or suspected causes of cancer. "
Answer:
Chemical cause cancer
Explanation:
The overall force acting on an object after all the forces are combined is _________
force?
Answer:
Hi... Your answer is total force
Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of cyanic acid (HCNO) and 0.80 mole of sodium cyanate (NaCNO) in enough water to make 1.0 liter of solution.
Ka(HCNO) = 2.0 x 10^-4
The pH of a buffer solution : 4.3
Further explanationGiven
0.2 mole HCNO
0.8 mole NaCNO
1 L solution
Required
pH buffer
Solution
Acid buffer solutions consist of weak acids HCNO and their salts NaCNO.
[tex]\tt \displaystyle [H^+]=Ka\times\frac{mole\:weak\:acid}{mole\:salt\times valence}[/tex]
valence according to the amount of salt anion
Input the value :
[tex]\tt \displaystyle [H^+]=2.10^{-4}\times\frac{0.2}{0.8\times 1}\\\\(H^+]=5\times 10^{-5}\\\\pH=5-log~5\\\\pH=4.3[/tex]