Answer:
All the pure substances are made up of atoms and group of atoms known as molecules. They also have weight, volume and colour white solids also have the shape and hardness or texture. Pure substances also have points at which they boil and solidify.
Answer:
Pure substances are defined as substances that are made of only one type of atom or molecule. The purity of a substance is the measure of the extent to which a given substance is pure.
Explanation:
What happens to the total mass of a substance undergoing a physical change
Answer: It stays the same
Explanation:
Answer: it stays the same (A)
Explanation:
did the test online got 100%
What can happen when tectonic plates move a few centimeters?
Answer:
whole continents can move.
When KCl dissolves in water
Answer:
They form K₂O (Potassium oxide) and HCl (Hydrochloric acid). This is because K and H are positively charged and O and Cl are negatively charged and cations only bond with anions.
Pls help me with this will mark brainliest
Answer:
Pulmonary circulation moves blood between the heart and the lungs. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body. It sends oxygenated blood out to cells and returns deoxygenated blood to the heart
Explanation:
Why does diamond not conduct electricity
Answer: no free electrons
Explanation: Diamond is very hard due to the strong covalent bonds and rigid tetrahedral 3d arrangement. It does not conduct electricity, as there are no electrons free to move and carry charge through the structure.
Photosynthesis produces (4 points)
carbon dioxide and energy
carbon dioxide and oxygen
glucose and oxygen
glucose and carbon dioxide
(I'm pretty positive it's C, but correct me if I'm wrong)
Answer:
Glucose and oxygen is produced during photosyntheis
Explanation:
Carbon dioxide and water are required for photosyntheis producing oxygen and glucose
Answer:
C.Glucose and oxygen
What is a chemical solution and what are the names of its components?
Answer:
A chemical solution is defined as a homogeneous mixture of two or more substances. There are two components of chemical solution that include solute and solvent.
Solute is the component that get dissolved in another substance and solvent is the substance that dissolve solute.
For example: carbon dioxide in water. Where carbon-dioxide is solute and water is solvent.
Name the following 3 structural formulas correctly, in order from left to right
Answer:
1. Methyl propanoate.
2. Propanol.
3. 2–pentyne
Explanation:
1. The functional group in this case is ester. We name ester by naming the group after the functional group (–COO) then followed by the parent compound with the name ending with –oate.
The group after the functional is methyl i.e —CH3.
The parent compound has 3 carbon i.e propane. The functional group replaces the –e in propane with –oate.
Therefore, the name of the compound is:
Methyl propanoate.
2. In this case the functional group is
–OH i.e alcohol.
The compound has 3 carbon i.e propane. The functional group replaces the –e in propane with –ol.
Therefore, the name of the compound is:
Propanol.
3. The triple bond represents the functional group in this case i.e alkyne. We'll give the triple bond the lowest low count by counting from the left. The triple bond is at carbon 2.
The compound has 5 carbon i.e pentyne since it contains triple.
The name of the compound is:
2–pentyne
How does the mass and height of an object affect the gravitational potential energy?
Answer: The higher up an object an is the greater it’s gravitational potential energy. This is because a tree has more mass, so it needs to be given more gravitational potential energy to reach the same height. So a change in gravitational potential energy also depends on the mass of the object that is changing height
Explanation:
The gravitational potential energy (P.E) depends on the mass of the body and the height at which it travels, the two quantities will therefore dictate the work done on the object which is eventually the same as magnitude of the gravitational potential energy P.E.
It is assumed that gravitational pull acts toward the earth surface. The more the object move upward the more the work is done on the object to pull it down.
This work done is equal to the gravitational potential energy P.E which can be expressed as:
P.E = mgh
Where
m = mass of the body
g = gravitational field strength
h = height
We can have different masses of object at different heights, but gravitational field strength will always remain constant on earth.
Since the gravitational potential energy P.E depend on the mass of the body and the height at which it travels, the two quantities will therefore dictate the work done on the object which is eventually the same as magnitude of the gravitational potential energy P.E.
Learn more here: https://brainly.com/question/12337396
C2H5OH(l)+CH3COOH(l) → CH3COOC2H5(l)+H2O(l) If the yield of ethyl ethanoate obtained when 20.00 g of ethanol is reacted with excess ethanoic acid is 30.27 g, calculate the percentage yield
Answer:
The percentage yield is 79.12%
Explanation:
The first thing we need to calculate here is the theoretical yield of ethyl ethanoate that can be obtained from 20g of ethanol.
Since the mole ratio is 1:1, then this is quite straightforward.
What we need to obtain at first here is the number of theoretical moles of ethanol reacting.
That would be mass of ethanol/molar mass of ethanol
Molar mass of ethanol is 46g/mol
Thus the number of moles is 20/46 = 0.4348 mole
Like it is indicated earlier, since the number of moles are equal from the balanced equation, it also means that 0.4348 mole of ethylethanoate is produced
Now, we need to know the mass of ethyl ethanoate produced
The mass can be calculated by multiplying the number of moles by the molar mass
The molar mass of ethyl ethanoate is 88g/mol
So the mass of it produced = 0.4348 * 88 = 38.2624 or let’s just say 38.26
Thus, the percentage yield will be;
Actual yield/Theoretical yield * 100%
From the question, our actual yield is 30.27g while our calculated theoretical yield is 38.26g
= 30.27/38.26 * 100% = 79.12%
Tyler measured the force of his grip. Which is the most likely reading?
A.
190kg
B.
190N
C.
1 lb
D.
20,000 N
E.
5 seconds
F.
18mg
Answer:
190n
Explanation:
190 190 and because it is easy to understand if you didn't understand my answer ask any man
If the atmospheric pressure in the laboratory is 1.2 atm, how many moles of gas were in each syringe? (Hint: Choose one volume and temperature pair from your data table to use in your ideal gas law calculation.)
Answer:
A: 2.525 x 10-4 mol
B: 2.583 x 10-4 mol
Explanation:
Part A:
Data Given:
. Temperature of water (H2O) = 21.3°C
Convert Temperature to Kelvin
T = °C + 273
T = 21.3 + 273 = 294.3 K
volume of (H2O) gaseous state = 5.1 mL
Convert mL to liter
1000 mL = 1L
5.1 ml = 5.1/1000 = 0.0051 L
Pressure = 1.2 atm
. no. of moles = ?
Solution
no. of moles can be calculated by using ideal gas formula
PV = nRT
Rearrange the equation for no. of moles
n=PV/RT......... (1)
where
P = pressure
V = Volume
T= Temperature
n = Number of moles
R = ideal gas constant
where
R = 0.08206 L.atm/ mol. K
Now put the value in formula (1) to calculate no. of moles of
n = 1.2 atm x 0.0051 L / 0.08206 L.atm.mol-1. K-1 x 294.3 K
n = 0.0061 atm.L / 24.162 L.atm.mol-1
n = 2.525 x 10-4 mol
no. of moles of gas (H2O) = 2.525 x 10-4 mol
Part B:
Data Given:
Temperature of water (H2) = 21.3°C
Convert Temperature to Kelvin
T = "C + 273
T= 21.3 + 273 = 294.3 K
volume of (H2) gas = 5.2 mL
Convert mL to liter
1000 mL = 1 L
5.2 ml = 5.2/1000 = 0.0052 L
Pressure = 1.2 atm
. no. of moles = ?
Solution
no. of moles can be calculated by using ideal gas formula
PV = nRT
Rearrange the equation for no. of moles
n= PV / RT......... (1)
where
P = pressure
V = Volume
T= Temperature
n = Number of moles
R = ideal gas constant
where
R = 0.08206 L.atm/mol. K
Now put the value in formula (1) to calculate no. of moles of
n = 1.2 atm x 0.0052 L/0.08206 L.atm.mol-1. K-1 x 294.3 K
n = 0.0062 atm.L/ 24.162 L.atm.mol-1
n = 2.583 x 10-4 mol
I
no. of moles of gas (H2) = 2.583 x 10-4 mol
Does the conductivity increase or decrease?
O It increases at first, then decreases.
O It continuously decreases
O It continuously increases
O lt decreases at first, then increases
Answer:
It continuously decreases.
Explanation:
the thermal motion makes the electrons to collide and disturb the free flow. Thus, conductivity is decreased.
Elements that form ionic bonds generally have how many valence electrons?
Answer:
they should have a number that can completely transfer and fill the other atom
Explanation:
example:
sodium(2.8.1)and Chlorine(2.8.7)the sodium will give chlorine the 1 valence electrobo so they both become stable(2.8)±and(2.8.8)–
magnesium(2.8.2)and oxygen(2.6)same way as above to abtain mg(2.8)±²and oxygen(2.8)–²
which accurately describes development?
Answer:
changing while growing
Explanation:
Answer: the answer is a
Please look at the photo and identify what’s in it!
Answer:
Explanation:
A battery
Answer:
Ac motor is in this images
1
Net ionic equations remove spectator ions and shows only the chemical species that are involved in the chemical reaction. Write the net ionic equation for the following acid base reaction.
Molecular Equation: 2 HCl (aq) + Mg(OH)2 (aq) → MgCl2 (aq) + 2 H2O (l)
Complete Ionic: 2 H+ (aq) + 2 Cl– (aq) + Mg2+ (aq) + 2 OH– (aq) → Mg2+ (aq) + 2 Cl– (aq) + 2 H2O (l)
Net Ionic Equation: ______________________________________________________
Answer:
The reaction of an acid and a base is called a neutralization reaction. ... However, in the reaction between HCl(aq) and Mg(OH) 2(aq), additional molecules of HCl and ... First, we will write the chemical equation with the formulas of the reactants ... The chloride ions are the only spectator ions I THINKS
Explanation:
PLSSS HELPPP MEEE WITH THIS QUESTIONNNNN NO GUESSING PLSSSS
Which process is shown in the plant cell below?
A= cell growth
B= cell reproduction
C= metamorphosis
D= photosynthesis
Answer:
B
Explanation:
Well, the cells are going through mitosis, which means that when the divide, they are going to be identical sister cells. Anyways, they are
How will you test for the gas which is liberated when hcl reacts with an active metal ?
ANSWER IT CORRECTLY PLEASE!!
The Osmotic pressure of blood is 7.65 ATM at 310 k. An aqueous solution of glucose is isotonic with blood has the percentage by volume
a.5.41%
b.3.54%
c.4.53%
d.53.4%
Answer:
Explanation:
Pv = n RT
P =7.65, T= 310K, for glucose n = moles= weight/molar mass= weight/180, R is gas constant
7.65* V =W/180 *0.0821 * 310
w/v= 7.65*180/0.0821*310 = 1377/25.45 = 54.10 =5.4%
In the lab, a student adds 4.5 g of sodium chloride (NaCl) to 100.0 g of water. Calculate the molality of the solution.
Answer:
0.77mol/Kg.
Explanation:
The following data were obtained from the question:
Mass of NaCl = 4.5g
Mass of water = 100g.
Molality =...?
Next, we shall determine the number of mole in 4.5g of NaCl. This can be obtained as follow:
Mass of NaCl = 4g.
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of mole NaCl =..?
Mole = Mass /Molar Mass
Number of mole of NaCl = 4.5/58.5
Number of mole of NaCl = 0.077 mole.
Next, we shall convert 100g of water to kilograms. This is illustrated below:
1000g = 1kg
Therefore, 100g = 100/1000 = 0.1Kg.
Finally, we can determine the molality of the solution as follow:
Molality is simply defined as the mole of solute per unit kilogram of solvent (water). Mathematically, it is represented as:
Molarity = mole of solute / kg of solvent
Mole of solute, NaCl = 0.077 mole
Kg of solvent = 0.1kg
Molality = 0.077mol/0.1kg
Molality = 0.77mol/Kg
The molarity of the solution is 0.77mol/Kg.
Calculation of the molarity of the solution:
Since
Mass of NaCl = 4.5g
Mass of water = 100g.
Here,
Mass of NaCl = 4g.
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Now
Mole = Mass /Molar Mass
= 4.5/58.5
= 0.077 mole.
Now
1000g = 1kg
So,
100g = 100/1000 = 0.1Kg.
Now
Molarity = mole of solute / kg of solvent
Mole of solute, NaCl = 0.077 mole
Kg of solvent = 0.1kg
So,
Molality = 0.077mol/0.1kg
= 0.77mol/Kg
Learn more about sodium here: https://brainly.com/question/14248836
You have nitrogen gas (N2) at a pressure of 0.5 atm, a volume of 25000 mL, and a temperature of 300 K, how many grams of nitrogen are present?
Answer:
About 7.109g
Explanation:
25000mL is the same as 25 liters.
[tex]PV=nRT \\\\0.5 (25)=n (0.0821) (300) \\\\n\approx 0.508[/tex]
Multiplying this by the molar mass of nitrogen, you get about 7.109 grams of nitrogen. Hope this helps!
Give two examples of solutions that you might find or prepare in a kitchen.
Explanation:
solid liquid
solid gas
liquid solid
What is the name of Al2(CO3)3 ?
Answer: Aluminum Carbonate
Explanation:
Answer:
Aluminum carbonate.
Explanation:
It is an aluminum salt form of carbonic acid.
The diagram shows Niels Bohr’s model of an atom.
A small green circle labeled Proton is surrounded by 4 concentric circles. The space inside the first concentric circle is labeled N = 1; the space between the first and second circle is labeled N + = 2; between the second and third N = 3, and between the third and fourth N = 4. Oblong gray shapes labeled Electron appear on the second and third concentric circles.
What happens when the electron moves from the first energy level to the second energy level?
Energy is absorbed, and an emission line is produced.
Energy is released, and an emission line is produced.
Energy is absorbed by the atom.
Energy is lost from the atom.
Answer:
Energy is absorbed by the atom.
Explanation:
Which substances are products of a fermentation reaction?
1.water and carbon dioxide
2.alcohol and carbon dioxide
3.soap and glycerol
4.ester and water
Answer:
2.alcohol and carbon dioxide
Explanation:
Fermentation is a metabolic process which is used to produce chemical changes in various organic substances. This process is used in many fields including biochemistry, where it is defined as the "extraction of energy from carbohydrates in the absence of oxygen". The main substances produced from fermentation reaction are alcohol, carbon dioxide and lactic acid.
Why are prefixes not used in naming ionic compounds?
A. Two ions can combine in only one combination.
B. The number of ions is not fixed in a compound.
C. A roman numeral is used instead of a prefix
D. A subscript follows each name instead of a prefix.
Answer:
A.
Explanation: thats what i got right on the quiz lol
Prefixes are not used in naming ionic compounds because two ions can combine in only one combination.
It is common in organic chemistry and with a few other molecular species, to name the compound using a prefix such as di, tri, tetra etc to indicate the positions of moieties in the molecule. This is important because there could be several possible combinations of atoms in a molecule.
In the case of ionic compounds, the combining ions can only have one possible arrangement.
Hence, the reason why prefixes are not used in naming ionic compounds is because two ions can combine in only one combination.
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At STP how many moles of
argon gas are present in 6.5
liters of argon gas
Answer:
0.289 molIn order to determine the number of moles of the given volume of Ar, divide the given volume by the molar volume of an ideal gas,
22.710 L/mol
Explanation:
So you have a volume of 6 .5
6.5L / 22.710 L/mol
L is eliminate .
6.5/ 22.710 L/mol = 0.286 mol
Using the older STP values of 0 ∘ C or 273.15 K , and pressure of 1 atm , molar volume is 22.414 L/mol .
6.5L /22.414 L/mol .= 0.289 mol
The pressure exerted by 0.002 moles of a gas in a 500 mL container at 25oC is:
Answer:
0.1715 atm
Explanation:
We use the Ideal gas equation to calculate this
Mathematically;
PV = nRT
rearranging, we have
P = nRT/V
from the question, we have
n = 0.002 moles
R = 0.082
T = 250 = 250 + 273 = 523 K
V = 500 ml = 500/1000 = 0.5 L
Plugging the values we have;
P = (0.002 * 0.082 * 523)/0.5
P = 0.1715 atm
Which group in the periodic table contains the three elements with the highest
electrical conductivities?
OA) Group 8
B) Group 12
C) Group 11
D) Group 7
Answer:
Group 12
Explanation:
Group 12 is also called a transition metal group. This group in the periodic table lies in between the groups or tables. These metals are classified as the transition metal in the table.
These metals are found from the group number 3 to 12. In the periodic table, These transition elements are ductile and malleable. These metal conduct heat and electricity.
These elements are generally called dense and less to react to the alkaline metal. Iron, copper-silver, gold is the most important transition metal.
Answer:
Group 11
Explanation:
Pf
