Answer:
For all these questions, we want to find the empirical and molecular formulae of various compounds given their percent composition and molar mass. The technique used to answer one of the questions can accordingly be applied to all of them.
Approaching the first question, we treat the percentages of each element as the mass of that element in a 100 g compound (as the percentages add up to 100%). So, our 100 g compound comprises 7.74 g H and 92.26 g C.
Next, we convert these mass quantities into moles. Divide the mass of each element by its molar mass:
7.74 g H/1.00794 g/mol = 7.679 mol H
92.26 g C/12.0107 g/mol = 7.681 mol C.
Then, we look for the molar quantity that's the smallest ("smaller," in this case, since there are only two), and we divide all the molar quantities by the smallest one. Here, it's a very close call, but the number of moles of H is slightly smaller than that of C. So, we divide each molar quantity by the number of moles of H:
7.679 mol H/7.679 mol H = 1
7.681 mol C/7.679 mol H ≈ 1 C/H (the value is actually slightly larger than 1, but we can treat it as 1 for our purposes).
The quotients we calculated represent the subscripts of our compound's empirical formula, which should provide the most simplified whole number ratio of the elements. So the empirical formula of our compound is C₁H₁, or just CH.
Here, it just so happens that we obtained whole number quotients. If we end up with a quotient that isn't a whole number (e.g., 1.5), we would multiply all the quotients by a common number that would give us the most simplified whole number ratio (so, if we had gotten 1 and 1.5, we'd multiply both by 2, and the empirical formula would have subscripts 2 and 3).
To find the molecular formula (the actual formula of our compound), we use the molar mass of the compound, 78.1134 g/mol. The molar mass of our "empirical compound," CH, is 13.0186 g/mol. Since our empirical formula represents the most simplified molar ratio of the elements, the molar masses of our "empirical compound" and the actual compound should be multiples of one another. We divide 78.1134 g/mol by 13.0176 g/mol and obtain 6. The subscripts in our molecular formula are equal to the subscripts in our empirical formula multiplied by 6.
Thus, our molecular formula is C₆H₆.
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As mentioned before, all the questions here can be answered following the procedure used to answer the first question above. In any case, I've provided the empirical and molecular formulae for the remaining questions below for your reference.
2. Empirical formula: C₁₃H₁₂O; molecular formula: C₁₃H₁₂O
3. Empirical formula: CH; molecular formula: C₈H₈
4. Empirical formula: C₂HCl; molecular formula: C₆H₃Cl₃
5. Empirical formula: Cl₄K₂Pt; molecular formula: Cl₄K₂Pt
6. Empirical formula: C₂H₄Cl; molecular formula: C₄H₈Cl₂
Which change does not increase the speed of reaction between zinc and hydrochloric acid?
By adding the decreasing the temperature, the speed of the reaction will not be increased.
What is speed of the reaction ?The reaction rate, which is a measure of how quickly reactants are consumed as well as products are created, determines the speed of a reaction.
When the temperature is lowered, the molecules move more slowly and collide less. The reaction's speed is slowed as the temperature drops.
Therefore, by adding the decreasing the temperature, the speed of the reaction will not be increased.
To know more about speed of reaction.
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How many liters of CH4 gas are there in 1.20 moles of CH4 when the gas is held under standard conditions?
Please answer quickly!
Answer:
26.88 L
Explanation:
When any gas is held under standard conditions, one mol will occupy 22.4 liters.
With the above information in mind, we can calculate how many liters would 1.20 moles of CH₄ gas occupy under standard conditions:
1.20 mol * 22.4 L/mol = 26.88 L
So 1.20 moles of CH₄ would occupy 26.88 liters.
How many moles are in 1.7 x 10^50 particles of Al?
2.8 × 10²⁶ moles Al
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
MolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 1.7 × 10⁵⁰ particles Al
[Solve] moles Al
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 1.7 \cdot 10^{50} \ particles \ Al(\frac{1 \ mol \ Al}{6.022 \cdot 10^{23} \ particles \ Al})[/tex][DA] Divide [Cancel out units]: [tex]\displaystyle 2.82298 \cdot 10^{26} \ moles \ Al[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
2.82298 × 10²⁶ moles Al ≈ 2.8 × 10²⁶ moles Al
Explore: Arrange the matter
from largest to smallest.
Organ
Molecule
Organelle
. Atom
Organism
. Cells
. Tissues
Elements
Answer:
The levels, from smallest to largest, are: molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere.
Explanation:
The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
Answer:
the matter
from largest to smallest.
- organism-organ-organelle-tissue-cell-atom-elements-molecule
Emma wrote, 'My investigation was good' , as her conclusion.
Philip said this was not a scientific conclusion.
Explain why Emma's conclusion is not scientific
Answer:
Emma's conclusion is not scientific. She is stating an opinion because she thinks her investigation was good which is not necessarily scientific.
How many cubic centimeters are in the block? if the length is 1, the width is 1 and the height is 1?
Answer:
Volume = [tex]1cm^3[/tex]
Explanation:
Volume of cube = [tex]s^{3}[/tex]
Wherein,
s = length of side
Hence,
If the length of each side is 1cm,
Volume = [tex]1^3[/tex]
= 1[tex]cm^3[/tex]
will gravitational force change based on a change of mass or a change of distance between objects
Answer:
The size of the gravitational force is proportional to the masses of the objects and weakens as the distance between them increases.
4. How many liters of solution would be needed in a 4.5M solution that contains
101.1g of KNO3?
why is cardboard, paper, or ceramic a better choice for coffee mugs?
A container of hydrogen peroxide originally has a mass of 28.96 grams and then completely decomposes into water and oxygen gas. The mass of water produced is 15.33 g. What mass of oxygen gas was also produced?
Answer:
dhshrvehduvhdhehejieeiie
Step 4: Model the energy change in the reaction.
a) Create an energy graph that illustrates the energy change in the reaction.
b) Construct your graph on a blank sheet of paper. Be sure to label the axes, provide a title, and
identify the reactants and products on the graph.
Answer:
Sorry if this is hard to see, this was the best I could do, but the top line says C3H8 + O2, and the bottom line says CO2 + H20, with the heat input being -2043.96 kJ/mol
Explanation:
This is correct for me
Bright red color (R) is dominant over grey color (r) in a type of fish , what color is the fish
Chemistry: Atoms and elements. having trouble figuring out how to find out what element these atoms represent any help will be apreciated.
Answer:
Elements are types of atoms that have a unique number of protons. In fact, from left to right, the periodic table is arranged by the number of protons that each element contains. oms make up matter. An atom is the smallest unit of matter that retains all of the chemical properties of an element.
Explanation:
Which statement is true regarding nuclear power plants?
The disposal of radioactive wastes is an intended benefit.
Uranium mining is an intended benefit.
Damage caused to the environment is an unintended consequence.
The creation of large amounts of electricity is an unintended consequence.
but its c because it dealing with power
Explanation:
1. Take a look at all the elements in period 3. What do you notice? *
5 points
A. They have the same number of energy levels
B. The number of energy levels decreases as you go across the period from left to right
C. They have the same number of valence electrons
D. The number of valence electrons decreases as you go across the period from left to right
Answer:
D
Explanation:
beacause all the elements in period 3 has different valence electrons hence you look at the first element in period 3 is sodium which has a valence electron of 1 when you go across the period to the right their valence electron decreases to be negative
Answer:
D is the correct answer i hope this is correct
can someone help me figure out what the Lewis structure for NCl2−?
Answer:
Chlorine is in group 7A, so it has 7 valence electrons
The Lewis structure for the molecule NCl²⁻ with -2 charge is attached in the image below.
What are Lewis structures?Lewis structures are also called as electron dot structures and can be drawn if the molecular formula of a compound is known. It provides information regarding the nature of bond and the position of atoms .
They are also capable of exhibiting the lone pair if any present in a molecule or compound.Lewis defined a base to be an electron pair donor and an acid to be an electron pair acceptor.
They are capable of reflecting electronic structure of elements and even the pairing of electrons . In the diagram, each dot represents an electron while a pair of dots represent a bond between the atoms.It helps in understanding the bonding between the two atoms.
Learn more about Lewis structures,here:
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For the balanced equation shown below, how many moles of N2 will react with 0.3034 moles of Mg?
3 Mg + N2 Mg3N2
Round answer to 4 sig-figs.
Answer:
0.1011 moles of N₂
Explanation:
This is the reaction:
3 Mg + N₂ → Mg₃N₂
3 moles of magnesium can react to 1 mol of nitrogen in order to produce 1 mol of magnesium nitride.
We can solve this by a rule of three:
3 mol of Mg need 1 mol of N₂ for the reaction
Then, 0.3034 moles of Mg may react to (0.3034 . 1) / 3 = 0.1011 moles of nitrogen.
The stoichiometry is 3:1
The image shows sedimentary rock layers with index fossils and a fault.
Which statement accurately describes the rock layers?
Layer 8 is older than layer 1.
Layer 3 is younger than layer 6.
Layer 4 and layer 10 are the same relative age.
Layer 2 and layer 9 are the same relative age.
Answer:
Layer 2 and layer 9 is the same relative age since it is the same type of rock and has the same fossils.
Hope this helped!
a moon phase that looks like a full circle is called.
Answer:
a full moon or new moon
Explanation:
If the substance in the diagram was heated to T2, what is happening if the substance is allowed to approach T1?
1.The average kinetic energy is decreasing
2. The average kinetic energy has increased
3. The highest energy level has decreased
4. Fewer molecules would have a lower energy level
5. More molecules have a higher energy level
Answer:
b
Explanation:
What type of chemical reaction is
2Al(s) + + 3Cl2(g) – 2AlCl3(s)
Answer:
It's a redox reaction.
calculate the mass of 0.5mols of CH3COOH
Answer:
30 g
Explanation:
In order to convert from moles of CH₃COOH to grams, we need to use its molar mass:
Molar mass of CH₃COOH= (Molar Mass of C)*2 + (Molar Mass of H)*4 + (Molar Mass of O)*2 = 60 g/molNow we convert moles into grams:
0.5 mol * 60 g/mol = 30 gSo 0.5 moles of CH₃COOH have a mass of 30 grams.
Cu2(s)+O2(g)=Cu2O(g)+SO2(g)
please help urgent will give brainiest
Answer:
2 Cu2S + 3 O2 = 2 Cu2O + 2 SO2
Explanation:
2 Cu2S + 3 O2 = 2 Cu2O + 2 SO2
name three pure elements and three pure compounds
Answer:
Pure elements:
Hydrogen(H)
Nitrogen(N)
Magnesium (Mg)
Pure Compounds:
Oxygen gas(O2)
Water (H2O)
Ammonia (NH3)
Explanation:
Hope it helps.Please mark me brainliest.^-^
If one mole of nitrogen is used how many liters of hydrogen are needed
Answer:
300
Explanation:
The
of a chemical reaction is the maximum amount of product that can be produced
Answer= Maximum amount of product that could be obtained under ideal conditions from a given amount of reactants.
Explanation:
The theoretical yields is the ideal maximum amount of a product that can be produced during a chemical reaction while the limiting reactant is the reactant that determines the maximum amount of product that can be formed. mitgliedd1 and 61 more users found this answer helpful.
In a chemical reaction, the reactants (beginning elements or compounds) but have the same number and type of atoms as the products (the new substance created). This is an example of...
a) law of conservation of mass
b) law of conservation of energy
c) covalent bonding
d) product synthesis
Answer:The law of conservation of matter says that matter cannot be created or destroyed. In chemical equations, the number of atoms of each element in the reactants must be the same as the number of atoms of each element in the products. ... There are two oxygen atoms in the reactants and two atoms of oxygen in the product.
Explanation:
3. A sample of air in a syringe exerts a pressure of 1.02 atm at 22.0°C. The syringe is placed in a boiling-water bath at 100.0°C. The
pressure is increased to 1.23 atm by pushing the plunger in, which reduces the volume to 0.224ml What was the initial volume?
Answer:
0.214 mL
explanation:
Ideal Gas law is applied to the ideal gases. The initial volume of air in the syringe when applied pressure and reducing the volume to 0.2234 mL is 0.214 mL.
What is the Ideal Gas Equation ?The equation relating all the characteristics of a gas and behaving or assuming to be ideal is the ideal gas law equation.
pV = nRT
Here, p is the pressure, V is the volume, R is the universal gas constant, n is the number of moles and T is the temperature.
According to the law, the initial and final values of gas are related as
[tex]\dfrac{P_{1} V_{1} }{T_{1} } =\dfrac{P_{2} V_{2} }{T_{2} }[/tex]
The initial pressure P₁ is 1.02 atm and final pressure P₂ is 1.23 atm.
The initial temperature T₁ is (22+273)=295 K and the final temperature (100+273)=373 K
The final volume V₂ given is 0.224 mL
Placing the values into the ideal gas equation and solving, we get the value of initial volume.
V₁= 0.214 mL
The initial volume of air in the syringe when applied pressure and reducing the volume to 0.2234 mL is 0.224 mL.
Learn more about Ideal gas law equation.
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Which of the following is an oxidation-reduction reaction?
ZnS(s) + 2O2(g) Right arrow. ZnSO4(s)
CaO(s) + H2O(l) Right arrow. Ca(OH)2(s)
6Li2O(s) + P4O10(g) Right arrow. 4Li3PO4(s)
SO2(g) + H2O(l) Right arrow. H2SO3(aq)
Answer:
A: ZnS(s) + 2O2(g) --> ZnSO4(s)
Explanation:
;) good luck
Answer:
The answer is A or the first choice
Explanation:
ZnS(s) + 2O2(g) Right arrow. ZnSO4(s)
HAVE A GREAT DAY STAY SAFE
What is a characteristic of asexual reproduction?
Answer:
Sexual reproduction