Answer:
Modern periodic law
Explanation:
There are many ways of stating the modern periodic law. Generally, the modern periodic law states that the properties of elements are a periodic function of their atomic numbers. That means, similar properties recur periodically when elements are arranged according to increasing atomic number.
Two scientists were largely responsible for our present day understanding of the modern periodic law, they are, Mendeleev and Moseley. Their work laid the foundation for the periodic table in its current form.
Balance the equations by inserting coefficients as needed.
equation 1:
CaCO3 + HCl -> CaCl2 + CO2 + H2O
CaCO3+HCl⟶CaCl2+CO2+H2O
equation 2:
C6H12O2 + O2 -> CO2 + H2O
C6H12O2+O2⟶CO2+H2O
Answer:
1. CaCO3 + 2HCl → CaCl2 + H2O + CO2
2. C6H12O2 + 8O2 → 6CO2 + 6H2O
Explanation:
The balanced chemical equation is (i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
What is balanced chemical equation?An equation with equal amounts of every atom of an element on both endpoints of the arrow was called a balanced equation.
Given chemical equation is:
(i) CaCO3+HCl⟶CaCl2+CO2+H2O
It can be seen that in left side of the chemical equation count of chlorine atom is one while right side of the chemical equation it is two. So, by multiplying 2 as a coefficient in the right side of the equation. Balanced chemical equation will be
CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+O2⟶CO2+H2O
It can be seen that, there are 12 hydrogen in the left side of the reaction while it is two hydrogen in the right side of the reaction. By multiplying 6 as a coefficient of hydrogen. Hence, the balanced chemical equation will be
C6H12O2+ 8O2⟶CO2+6H2O
The balanced chemical equation is
(i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
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What is the mass in grams of 2.4 x 10-2 mol K2SO4
All good experiments should be...
What is the approximate vapor pressure when the liquid water boils at about 50°C?
380 mmHg
760 mmHg
100 mmHg
5 mmHg
Answer:
380
Explanation:
If an atom has a neutral charge, it must have
Answer:
Proton or electron. I think, not sure.
Explanation:
A proton and an electron have an equal amount but an opposite type of charge. Thus, if an atom contains equal numbers of protons and electrons, the atom is described as being electrically neutral.
eletrons I'm pretty sure
How many grams of NO2 would be formed from 1.0 mole of NO and excess of O2?
Answer:
Mass = 46 g
Explanation:
Given data:
Number of moles of NO = 1.0 mol
Amount of O₂ = excess
Mass of NO₂ formed = ?
Solution:
Chemical equation:
2NO + O₂ → 2NO₂
Now we will compare the moles of No with NO₂.
NO : NO₂
2 : 2
1 : 1
Mass of NO₂ in gram:
Mass = number of moles × molar mass
Mass = 1 mol ×46 g/mol
Mass = 46 g
When nitrogen, oxygen, fluorine, sodium, magnesium and aluminum ionize, they all will have:
a. different electron configuration from each other.
b. an unchanged electron configuration.
c. the same charge.
d. the same electron configuration (isoelectronic) as neon.
[Definition: The word isoelectronic means that when you write out the electron configuration they are the same. An exam would be He and Li whereby both of them have 2 electrons and therefore they are both are 1s2 in their electron configurations.]
Answer:
the same electron configuration (isoelectronic) as neon.
Explanation:
The electron configuration refers to the distribution of electrons of an atom or molecule in atomic or molecular orbitals. Electronic configuration is also known as an electronic structure.
When nitrogen, oxygen, fluorine, sodium, magnesium and aluminum ionize, they all will have the same electron configuration (isoelectronic) as neon.
A sample of propane, C3H8, contains 13.8 moles of carbon atoms. How many total moles of atoms does the sample contain
Answer:
[tex]Total = 50.6\ moles[/tex]
Explanation:
Given
[tex]Propane = C_3H_8[/tex]
Represent Carbon with C and Hydrogen with H
[tex]C = 13.8[/tex]
Required
Determine the total moles
First, we need to represent propane as a ratio
[tex]C_3H_8[/tex] implies
[tex]C:H = 3:8[/tex]
So, we're to first solve for H when [tex]C = 13.8[/tex]
Substitute 13.8 for C
[tex]13.8 : H = 3 : 8[/tex]
Convert to fraction
[tex]\frac{13.8}{H} = \frac{3}{8}[/tex]
Cross Multiply
[tex]3 * H = 13.8 * 8[/tex]
[tex]3 H = 110.4[/tex]
Solve for H
[tex]H = 110.4/3[/tex]
[tex]H = 36.8[/tex]
So, when
[tex]C = 13.8[/tex]
[tex]H = 36.8[/tex]
[tex]Total = C + H[/tex]
[tex]Total = 13.8 + 36.8[/tex]
[tex]Total = 50.6\ moles[/tex]
How do weathering and deposition differ? (4 points)
оа
Weathering breaks down rocks; deposition leaves them in new places.
Ob
Weathering has to do with air; deposition has to do with plants.
Ос
Weathering occurs only in summer; deposition occurs year-round.
Od
Weathering can be chemical or physical; deposition is only chemical.
Answer:
Oa. Weathering breaks down rocks; deposition leaves them in new places.
Explanation:
Did test and got it right.
Using charge to describe an atom
Answer:
this atom has nine electrons
An element that reacts with oxygen to form XO2 compounds and with chlorine to form XCI4 compounds???
Answer:
An element X reacts with oxygen to form XO
and with chlorine to form XCl
. XO
is a white solid that melts at high temperatures (above 1000 degrees C). Under usual conditions, XCl
is a colorless liquid with a boiling point of 58 degrees C.
Explanation:
PLEASE HELP!!
There are 5.5 L of a gas present at -38.0 C. What is the temperature if the volume of the gas has changed to 1.30 L?
Answer:
The answer is 55.54 KExplanation:
In order to find out the final temperature we use the formula for Charles's law which is
[tex] \frac{V_1}{T_1} = \frac{V_2}{T_2} \\ [/tex]
where
V1 is the initial volume
T1 is the initial temperature in Kelvin
V2 is the final volume
T2 is the final temperature in Kelvin
Since we are finding the final temperature
[tex]T_2 = \frac{V_2T_1}{V_1} \\ [/tex]
rom the question
V1 = 5.5 L
T1 = -38°C = -38 + 273 = 235 K
V2 = 1.30 L
We have
[tex]T_2 = \frac{1.30 \times 235}{5.5} = \frac{305.5}{5.5} \\ = 55.545454...[/tex]
We have the final answer as
55.54 KHope this helps you
The equilibrium constant for A + 2B → 3C is 2.1 * 10^-6
Determine the equilibrium constant for 2A + 4B → 6C.
a- 4.2 * 10^-6
b- 4.4 * 10^-12
c- 2.3 *10^11
d- 1.8 *10^-11
e- None of these
Answer:
b- 4.4 * 10^-12.
Explanation:
Hello.
In this case, as the reaction:
A + 2B → 3C
Has an equilibrium expression of:
[tex]K_1=\frac{[C]^3}{[A][B]^2}=2.1x10^{-6}[/tex]
If we analyze the reaction:
2A + 4B → 6C
Which is twice the initial one, the equilibrium expression is:
[tex]K_2=\frac{[C]^6}{[A]^2[B]^4}[/tex]
It means that the equilibrium constant of the second reaction is equal to the equilibrium constant of the first reaction powered to second power:
[tex]K_2=K_1^2[/tex]
Thus, the equilibrium constant of the second reaction turns out:
[tex]K_2=(2.1 * 10^{-6})^2\\\\K_2=4.4x10^{-12}[/tex]
Therefore, the answer is b- 4.4 * 10^-12.
Best regards.
how many moles of h2 can be made from the complete reaction of 3.5 moles of al?
Given: 2Al+6HCL 2Alcl3+3h2
Answer:
From the given equation, we can see that for every 2 moles of Al, we get 3 moles of H2
So, we can say the the number of moles of H2 is 3/2 times the number of moles of Al
We are given the number of moles of Al and we have to find the number of moles of H2
We have deduced the relationship:
Moles of Al * 3 / 2 = Moles of H2
Replacing the variables with given values
3.5 * 3 / 2 = Moles of H2
Moles of H2 = 5.25 moles
Draw molecules that satisfy the following prompts:
1. All molecules must have a minimum of 12 Carbon atoms and exactly 3 heteroatoms (not carbon or hydrogen atoms).
2. You may not use the same molecule twice for any parts of this question.
4. You do not need to look up solubility information, but the answers must be reasonable (supported by the concepts that we have discussed). Also, the structures must be reasonable (improper structures, e.g. carbon with 5 bonds or oxygen with one bond and no charge, will not receive any credit).
a. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M HCl(aq) and dichloromethane.
b. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M NaOH(aq) and dichloromethane.
c. Draw two non-charged molecules that will be separated using neutral water and dichloromethane and in a separatory funnel.
Answer:
see images attached
Explanation:
Here we are trying to perform solvent extraction. In solvent extraction, there must be an aqueous phase and an organic phase.
One of the species to be separated is extracted in greater concentration in the aqueous phase while the other is extracted in greater concentration in the organic phase.
The phase into which each specie is extracted depends on the nature of the specie.
Two structures are shown in the images attached that will be separated by the methods shown in (a) (b) (c) in the question
where in water is being converted into a gaseous form?
evaporation
condensation
transportation
precipitation
Answer:
It's called Evaporation.
Why are noble gases nonreactive?
A
Their melting points are too high to react.
B
They have 8 valence electrons making them inert, so they do not react.
C
They have 8 valence electrons, making them too dense to react.
D
They have 18 valence electrons, making them over expanded, so they cannot react.
Answer:
B
Explanation:
Answer:
B
Explanation:
Which of these is the best definition of biotechnology??
A) The study of chemical processes in living things
B) the use and application of living things and science
C) the application of engineering principles to solve medical problems
D) the study of forces
Why can we hear different radio stations?
Your radio picks up those radio waves and channels them into electric circuits in your radio that convert them into sounds you can hear.
How many milliliters of 10.7 M perchloric acid solution should be used to prepare 5.50 L of 0.200 M
Answer:
102.8 mL.
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M1) = 10.7 M
Molarity of diluted solution (M2) = 0.2 M
Volume of diluted solution (V2) = 5.5 L
Volume of stock solution needed (V1) =.?
The volume of the stock solution needed can be obtained by using the following formula:
M1V1 = M2V2
10.7 × V2 = 0.2 × 5.5
10.7 × V2 = 1.1
Divide both side by 10.7
V2 = 1.1 / 10.7
V2 = 0.1028 L
Finally, we shall convert 0.1028 L to millilitres (mL) in order to obtain the desired result. This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.1028 L = 0.1028 L × 1000 mL / 1 L
0.1028 L = 102.8 mL
Therefore, 0.1028 L is equivalent to 102.8 mL.
Thus, 102.8 mL of the stock solution (i.e perchloric acid) is needed.
an atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom
Answer:
Atomic mass =70
Explanation:
Mass number is total protons +total neutrons
A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
Answer:
The correct answer is 146 g/mol
Explanation:
Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
Therefore, the molar mass of the compound is 146 g/mol
Calculate the volume of the gas, in liters, if 1.75 mol has a pressure of 1.28 atm at a temperature of -7 ∘C
Answer:
A sample of an ideal gas has a volume of 2.21 L at 279 K and 1.01 atm. Calculate the pressure when the volume is 1.23 L and the temperature is 299 K.
You need to apply the ideal gas law PV=nRT
You have the pressure, P=1.01 atm
you have the volume, V = 2.21 L
The ideal gas constant R= 0.08205 L. atm/ mole.K at 273 K
find n = PV/RT = (1.01 atm x 2.21 L / 0.08205 L.atm/ mole.K x 273 K)
n= 0.1 mole, Now find the pressure for n=0.1 mole, T= 299K and
L=1.23 L
P=nRT/V= 0.1mole x 0.08205 (L.atm/ mole.K x 299 k)/ 1.23 L
= 1.994 atm
Explanation:
Answer each of the following questions with increases, decreases, or does not change.
a) If the intermolecular forces in a liquid increase, the normal boiling point of the liquid increases .
b) If the intermolecular forces in a liquid increase, the vapor pressure of the liquid does not change .
c) If the surface area of a liquid increases, the vapor pressure increases .
d) If the temperature of a liquid decreases, the equilibrium vapor pressure increases .
Drag and drop your selection from the following list to complete the answer:
does not change decreases increases
Answer:
a) increases
b) decreases
c) does not change
d) increases
Explanation:
The vapour pressure of a liquid is dependent on;
I) the magnitude of intermolecular forces
II) the temperature of the liquid
Hence, when any of these increases, the vapour pressure increases likewise.
Similarly, the boiling point of a liquid depends on the magnitude of intermolecular forces present because as intermolecular forces increases, more energy is required to break intermolecular bonds.
Lastly, increase in surface area of a liquid does not really affect it's vapour pressure.
Help plzzzzzzzzzzzzzzz
Answer:
um wheres thepassage?
Explanation:
Use the periodic table to identify the chemical symbol or name for each element below.
zirconium:
zr
rhenium:
re
: As
: K
tin:
yttrium:
: Yb
Answer:
zirconium is Zr
rhenium is Re
As is arsenic
K is potassium
tin is Sn
yttrium is Y
ytterbium is Yb
Explanation:
With the help of the periodic table, the identification of the chemical symbol or name for each element is represented as follows:
Zirconium: Zr. Rhenium: Re. Arsenic: As.Potassium: K.Tin: Sn. Yttrium: Y. Ytterbium: Yb. What are the chemical elements?Chemical elements may be defined as any type of substance that cannot be further decomposed into simpler substances through the utilization of other ordinary chemical processes or external factors. These elements possess specific physical as well as chemical properties distinctly.
In the modern periodic table, each element is arranged on the basis of its increasing atomic number. Each element possesses its unique symbol, atomic mass, and physical properties like boiling points, melting points, density, etc.
Therefore, with the help of the periodic table, the identification of the chemical symbol or name for each element is well represented above.
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4.5 tons → lbs
4.5 tons equals how many pounds
Answer:
9000 pounds
Explanation:
9000 pounds
Answer: 9000 lbs.
Explanation: 4.5 tons = 9000 pounds.
Solid calcium chlorate decomposes to form solid calcium chloride and oxygen gas.
Write the balanced chemical equation for the reaction described. Phases are optional.
equation:
Answer:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Explanation:
Chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Balance chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Step 1:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 2
Step 2:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 6
Which of the following are mole ratios from the balanced chemical equation below? Select all that
apply.
FeCl3 + 3HF - FeF3 + 3HCI
1 mole HF/1 mole HCI
3 mole HF/1 mole FeF3
1 mole FeCl3/3 mnole HF
3 mnole HF/1 mole FeCl3
The mole ratio of the given reaction is 1 mole HF/1 mole HCI; option A.
What are mole ratios?Mole ratios are ratios of the moles of reactants and products in a balanced chemical equation of a reaction.
Mole ratios are obtained from balanced chemical equations.
The balanced equation of the reaction is given below:
FeCl3 + 3HF ----> FeF3 + 3HCIThe mole ratio of the given reaction is 1 mole HF/1 mole HCI.
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Why aren’t two hydrogen atoms bonded together considered a compound? Explain.
Answer:
Hydrogen gas (H2) is a molecule, but not a compound because it is made of only one element. Water (H2O) can be called a molecule or a compound because it is made of hydrogen (H) and oxygen (O) atoms. There are two main types of chemical bonds that hold atoms together: covalent and ionic/electrovalent bonds.