Answer:
A = 66.98 square in.
Explanation:
The Area of a sector is given by the formula
[tex]A = \frac{\theta}{360}\times \pi r^2[/tex]
here θ is the central angle and r is the radius
given that θ = 120° and radius = 8 inches
[tex]A = \frac{120}{360}\times3.14\times 8^2[/tex]
A = 66.98 square in.
How many grams of FeCl3 are needed to make 1.5 L of a solution with a molarity of 0.450 M?
What can a nation do to improve the exchange rate of its currency?
A.
try to improve its balance of trade
B.
try to decrease its trade surplus
C.
try to lower its gross domestic product (GDP)
D.
try to export less while importing more
Answer:
A
Explanation:
balance the trades and improving them
Answer:
A:try to improve it's balance of trade
Explanation:
what is the molecular weight of a gas which diffuses 1/50 as fast as hydrogen
125 cm3 of a solution contains 0.25 moles of the solute. What is the concentration of the solution?
Answer:
Explanation:
125 cm3 -> 0.125 L
M = no. mole / volume (L)
M = 0.25 / 0.125 = 2 M
2.7 x 10^25 molecules of MnO equals how many moles?
Answer:
27 and 24 zeroes following it
Explanation:
10^25 is 100...(continues for 25 zeroes)
Now we multiply it by 2.7, making it 24 zeroes afterwards.
Avogadro's numbers are used to calculate the number of moles from molecules. There are 44.8 moles in MnO.
What are molecules?Molecules are the unit of the compound that may have the same or different atoms in it. The number of molecules is used to calculate moles from Avogadro's number.
By Avogadros number 1 mole of substance = 6.02 x 10²³ molecules
So, 2.7 x 10²⁵ molecules will have moles:
(2.7 x 10²⁵ molecules × 1 mole) ÷ (6.02 x 10²³ molecules) = 0.448 × 10² moles
Therefore, there are 44.8 moles of MnO.
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Calcule el peso de cromato sodico, Na2CrO4, necesario para preparar 200g de una disolución al 20% de Na2CrO4
Answer:
40g de cromato sódico serán necesarios
Explanation:
Una solución 20% de Na2CrO4 contiene 20g de Na2CrO4 por cada 100g de solución (Esto es, soluto + solvente). Para preparar 200g de la disolución en mención serán necesarios:
200g solucion * (20g Na2CrO4 / 100g Solución) =
40g de cromato sódico serán necesariosWhen the pH of a solution is changed from 4 to 3, the hydronium ion concentration of the
solution
A)
increases by a factor of 10
B)
decreases by a factor of 100
C)
increases by a factor of 100
D)
decreases by a factor of 10
Answer:increases by a factor of 10
Explanation: the concentration of the solution changed from 4 to 3
I para realizar un receta casera de bizcocho se necesitan 100 gramos de azúcar, calcula los moles a los que equivale y el número de moléculas de sacarosa.
The complete question is as follows: I want to make a homemade cake recipe you need 100 grams of sugar, calculate the moles to which it is equivalent and the number of molecules of sucrose.
Answer: In 100 grams of sugar there are 0.292 moles and the number of molecules of sucrose are [tex]1.76 \times 10^{23}[/tex].
Explanation:
Given: Mass = 100 g
Molar mass of sugar = 342.3 g/mol
As number of moles is the mass of substance divided by its molar mass.
Hence, moles of sucrose are calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{100 g}{342.3 g/mol}\\= 0.292 mol[/tex]
According to mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules.
Hence, the number of molecules present in 0.292 mol are calculated as follows.
[tex]0.292 mol \times 6.022 \times 10^{23}\\= 1.76 \times 10^{23}[/tex]
Thus, we can conclude that in 100 grams of sugar there are 0.292 moles and the number of molecules of sucrose are [tex]1.76 \times 10^{23}[/tex].
The diagram shows the basis for forming which of the following?
O nucleic acids
O proteins
O polysaccharides
O lipids
1. The electronic configuration of chlorine is
1. 2,7
II. 2,8,8,7
III. 2,8,7
IV. 2,7,8
Answer:
Chlorine has atomic number 17. Its electronic configuration is 2, 8, 7. It is the second-lightest of the halogens, it appears between fluorine and bromine in the periodic table.
Answer:
III
Explanation:
From the periodic table, Chlorine(Cl) has 17 protons.
And when arranging the proton of elements each shell has a number protons it can take, i.e
2,8,8,8..........
The first shell can only take a maximum of 2 protons while the second shell upwards takes a maximum of 8 protons
Now we want to arrange Chlorine;
1st shell = 2
2nd shell = 8
2 + 8 = 10
17(no. of Chlorine protons) - 10
= 7
therefore,
3rd shell = 7
Therefore,
The electronic configuration of chlorine is
2,8,7
Explain how to convert a mass of compound A to a mass of compound D in words using the following reaction:
2A + 4B = C + 3D
You don't have to just give me the answer but if you can help me understand id appreciate it greatly
Answer:
1. Convert the mass of A to moles dividing in molar mass
2. Convert the moles of A to moles of D (2mol A = 3mol D)
3. Convert the moles of D to mass multiplying by its molar mass
Explanation:
As you can see in the equation, 2moles of A produce 3 moles of D, the equation is:
2mol A = 3mol D
But in the problem you are having the mass of A and you need the mass of D. That means you require to convert the mass of A to moles. With the moles of A you can find the moles of D and, as last, you need to convert the moles of A to mass.
To convert mass to moles or vice versa you must use Molar Mass. That means, the answer is:
1. Convert the mass of A to moles dividing in molar mass2. Convert the moles of A to moles of D (2mol A = 3mol D)3. Convert the moles of D to mass multiplying by its molar mass_______ reach the surface first during an earthquake.
Rayleigh waves
P waves
Love waves
S waves
PLEASE HELP!!!!!!
The average number of drops of NaHCO3 in the titration lab was 142. Calculate the number of moles of NaCHO3 that were required to neutralize the CH3COOH in the vinegar.
- 1 mole of acetic acid was required for 2 moles of sodium bicarbonate
- 1 mole of acetic acid was required for 1 mole of sodium bicarbonate
- 2 mole of acetic acid was required for 1 mole of sodium bicarbonate
- 1 mole of acetic acid was required for 3 mole of sodium bicarbonate
Answer: The correct option is 1 mole of acetic acid was required for 2 moles of sodium bicarbonate
Explanation:
We are given:
Average number of drops of sodium bicarbonate = 142
The chemical equation for the reaction of sodium bicarbonate and acetic acid in vinegar follows:
[tex]NaHCO_3+CH_3COOH\rightarrow CH_3COONa+H_2CO_3[/tex]
From the stoichiometry of the reaction:
1 mole of sodium carbonate reacts with 1 mole of acetic acid in vinegar.
Hence, the correct option is 1 mole of acetic acid was required for 2 moles of sodium bicarbonate
What type of structure are ionic lattices?
Big structures
Small structures
Tiny structures
Giant structures
Answer:
Giant structures
Explanation:
An ionic compound is a giant structure of ions. The ions have a regular, repeating arrangement called an ionic lattice . The lattice is formed because the ions attract each other and form a regular pattern with oppositely charged ions next to each other.
How would it have been if particles of matter had no space?
Answer:
Matter is made of small particles of atoms or molecules. ... The particles in the solid are touching with very little space between them. The particles in a liquid usually are still touching but there are some spaces between them. The gas particles have big distances between them.
Which of the following emits a beta particle?
alpha particle
nucleus
hydrogen atoms
photoelectrons
PLEASE HELP : Arrange the following elements into a food chain: plants, snake, Sun, hawk, and mouse.
Answer:
Plants ➯ Mouse ➯ Snake ➯ Hawk ➯ Sun
Explanation:
In Order As A Food Chain
The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.
What is element?A substance that could not be further decomposed according to any chemical reaction is known as a chemical element.
What is food chain?
The flow of nutrients as well as energy through such an ecosystem is described by a food chain. Energy is first produced by plants at the most fundamental level, and then it is used by higher-level species like herbivores. Energy is then transmitted from one carnivore to the next when they eat the herbivores.
The elements are arranged into food chain like plants ⇒Mouse ⇒ Snake⇒ Hawk ⇒ Sun.
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Which of these is an example of a prosthesis?
A. A hearing aid
B. A textbook
C. Gloves
D. A pair of boots
Answer:
hearing aid
Explanation:
an artificial body part
A hearing aid is an example of a prosthesis. Therefore, option A is correct.
A prosthesis is an artificial device or replacement for a missing body part or function. In the case of a hearing aid, it is a device designed to assist people with hearing loss by amplifying sound. It acts as a substitute for the natural function of the ear.
A textbook is a written educational resource, gloves are protective coverings for the hands, and a pair of boots is footwear. These items do not serve as artificial replacements for missing body parts or functions.
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Sketch 10 atoms of aluminum and 6 molecules of oxygen gas in the container on the left. In the right container, sketch the contents after the reaction is complete.
Answer:
Sketch 10 atoms of aluminum and 6 molecules of oxygen gas in the container on the left. In the right container, sketch the contents after the reaction is complete.
Explanation:
The balanced chemical equation of the reaction is:
[tex]4Al + 3 O_2 -> 2Al_2O_3[/tex]
Though there are 10 atoms of Al, only four atoms will react with every three molecules of oxygen.
Hence, right side the product formed is --- Al2O3.
What is the empirical formula of a compound containing 5.03 g carbon, 0.42 g hydrogen, and 44.5 g of chlorine
Answer:
CHCl₃
Explanation:
We have the following data:
C = 5.03 g
H = 0.42 g
Cl= 44.5 g
First, we divide each mass by the molar mass (MM) of the chemical element to calculate the moles:
MM(C) = 12 g/mol
moles of C = mass/MM(C) = 5.03 g/(12 g/mol) = 0.42 mol C
MM(H) = 1 g/mol
moles of H = mass/MM(H) = 0.42 g/(1 g/mol) = 0.42 mol H
MM(Cl) = 35.4 g/mol
moles of Cl = mass/MM(Cl) = 44.5 g/(35.4 g/mol) = 1.26 mol Cl
Now, we divide the moles by the smallest number of moles (0.42):
0.42 mol C/0.42 = 1 C
0.42 mol H/0.42 = 1 H
1.26 mol Cl/0.42 = 3 Cl
Thus, the C:H:Cl ratio is 1:1:3.
Therefore, the empirical formula is CHCl₃
Answer:
CHCl₃
Explanation:
If the half life of iridium-182 is 15 years, how much of a 3 gram sample is left after 2 half-lives?
A) .57 grams
B) .70 grams
C) 2.25 grams
D) .75 grams
Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182, [tex]t_{(1/2)}[/tex] = 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;
[tex]N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}} }[/tex]
For two half lives, t = 2 × [tex]t_{(1/2)}[/tex]
∴ t = 2 × 15 = 30
[tex]\dfrac{t}{t_{(1/2)}} = \dfrac{30}{15} = 2[/tex]
[tex]\therefore N(t) = 3 \times\left (\dfrac{1}{2} \right )^2 = 0.75[/tex]
∴ The amount left, N(t) = 0.75 grams
ANSWER FAST
What is the relationship between Ka and Kb with Kw?
(a) The sum of Ka and Kb equals the auto-dissociation constant for water.
(b) The product of Ka and Kb equals the auto-dissociation constant for water.
(c) The quotient of Ka and Kb equals the auto-dissociation constant for water.
(d)The difference of Ka and Kb equals the auto-dissociation constant for water.
In a nonpolar covalent bond, electrons are
a. Located in a mobile "sea" shared by many ions
b. Transferred from one atom to another
c. Shared equally between two atoms
d. Shared UNequally between two atoms
Answer: c. Shared equally between two atoms
Electrons are shared equally because the atoms have the same electronegativity.
Which statement best describes the diagram
Explanation:
the answer will be A
The catalyst cannot be at point A since that's the reactant
Pathway B requires more energy, which makes it slower and harder for the reaction to finish
point D is the product
A few substances are arranged in the increasing order of ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement?
(a) Water, air, wind
(b) Air, sugar, oil
(c) c Oxygen, water, sugar
Answer:
A.
Explanation:
PO WATER,AIR,WIND
Is soup pure or impure?
Answer:
I think it's impure . Hope this helps you
Answer:
I think is pure but not 100% pure.
if you have 5.42 x 1024 aluminum atoms, approximately how many moles is that
Answer:
It is approximately 9 moles
Explanation:
Divide the aluminum atoms by Avogadro's number
(5.42*10^24)/(6.02*10^23)
= approx. 9 moles
PLEASEEEE HELPPPP!!!
What is a spontaneous change?
A. One that has an ordered arrangement of particles.
B. One that occurs on its own.
C. One that has a random arrangement of particles.
D. One that occurs when one specific event happens.
Answer:
B.
Explanation:
A spotaneous change is one which occurs on its own
A spontaneous change is one that occurs on its own.
What is a Spontaneous Process ?A spontaneous process is a process which has a natural tendency to occur in one direction , It has no relation with the speed , It can be fast or it can be slow but it doesn't require any external factors to happen.
such reactions might not face change in energy but it will see change in the way the matter or energy is distributed
The example of a spontaneous reaction is the decay of radioactive elements.
Example of Spontaneous Process is also water flowing downhill, it has the natural tendency to flow in that direction.
A spontaneous change is one that occurs on its own.
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Which kind of energy is stored in the chemical bonds of molecules found in
wood?
A. Mechanical energy
B. Potential energy
C. Gravitational energy
D. Kinetic energy
Answer:
B. Potential energy
Explanation:
It's not mechanical energy, because it is not doing work
It's not kinetic energy because it;s not moving
It's not gravitational energy because it is not above the ground
It is potential energy because it is stored energy
What is this picture an example of?
A. carbon cycle
B. nitrogen cycle
C. water cycle
D. ecological succession
PLEASE HELP
Sorry if the picture is bad Quality
Answer:
i think it is D
Explanation:
i dont know what you are learning but ecological succession is the change of enviroment pretty much.