Answer:
A. When two aqueous solutions are mixed, a precipitate is formed.
Explanation:
The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.
The other three answer choices are indicative of physical changes (temperature change, phase change, color change).
When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.
Hence, option A is correct answer.
What is Chemical change ?Chemical change are those changes in which substance changes chemical composition. These changes are permanent changes. In chemical change new substances formed and in chemical change substances can not get back into its original form. It is irreversible change.
What is Physical change ?Physical changes are those changes in which substance changes physical properties only. Properties like temperature, pressure, shape, color, size, state (solid, liquid and gas). These changes are temporary in nature. In physical change no new substances formed. It is reversible change.
Now, check all the options one by one:
Option (A): When two aqueous solutions are mixed, a precipitate is formed is a chemical change. Since precipitation indicate a chemical reaction (that is double displacement reaction).
Option (B): As ammonium nitrate dissolved in water causes the temperature to decrease is a physical change because heat energy is absorbed here and it is a endothermic reaction.
Option (C): Alcohol evaporates when left in an open container is a physical change because evaporation is a physical change as it changes the state from liquid state to gas state.
Option (D): Water is added to blue copper (II) chloride solution. The resulting mixture if lighter blue in color is a physical change as properties like change in color is physical change.
Thus, from above conclusion we can say that When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.
Hence, option A is correct answer.
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What is the molar mass of PbSO4?
Answer:
=303.2g
Explanation:
molar mass of Pb = 207.2g
atomic mass of S = 32g
atomic mass of O = 16g
Solution
PbSO4
= 207.2 + 32 + 4 (16)
= 239.2 + 64
= 303.2 g
The molar mass of compound lead sulfate is 207.2 g.
Molar mass of a compound or a molecule is defined as the mass of the elements which are present in it.The molar mass is considered to be a bulk quantity not a molecular quantity. It is often an average of the of the masses at many instances.
Molar masses of an element are given as relative atomic masses while that of compounds is the sum of relative atomic masses which are present in the compound.
atomic mass of S = 32g
atomic mass of O = 16g
PbSO₄= 207.2 + 32 + 4 (16)= 239.2 + 64 = 303.2 g.
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help please i need this
What BEST describes the relation of a new population to an increase in the amount of space it occupies? a - The population will die out
b - The population will remain constant
c - The population will grow exponentially
The burning of fossil fuels, like coal, oil, and natural gas, DO NOT contribute to the presence of greenhouse gases in the atmosphere.
True
or
False
Answer:
false statements because they are all nonrenewable resources
Photosynthesis needs water and carbon dioxide to happen. These 2 ingredients are called _______.
number of molecules in lithium oxide
4li2O
Answer:
Explanation:
Lithium is in group 1 so there's 1 outermost shell electron.
Oxygen is in group 6 so there's 6 outermost shell electron.
To react lithium with oxygen, we need 2 lithium and 1 oxygen
Each lithium transfer 1 electron to the oxygen and oxygen gain 2 electrons.
[tex]Li_{2}O\\[/tex] formed.
If there's 4 lithium oxide, 4 molecules will be there.
If you mean how many ATOMS are there, there will be 3×4=12 atoms.
1) How many molecules are in 0.02 moles of beryllium iodide?
Answer:
3 grams??
Explanation:
I think this would be the answer you are looking for.
What is produced when concentrated aqueous sodium chloride is electrolysed?
A certain protein transports a sodium ion from the inside of the cell membrane to the outside using active transport. Which of the following must be true? A. There is no change in concentration before or after transport. B. The transport process did not use chemical energy. C. After transport, the concentration of protein in the cell decreases. D. After transport, the concentration of sodium is lower inside the cell.
I need help with this chem problem!
HELP ME
Elements in a vertical column on the Periodic Table have similar properties and are all members of the same
of elements.
А
molecule
B
phase
С
atom
D
group
Answer:
D group
................
What is the correct shape and polarity of a water molecule
Answer:
D
Explanation:
because both H's should be positive and O is supposed to be negative.
Copper has a specific heat of 0,900 J(g C). How much energy in kJ is needed to raise the temperature of a 700 g block of aluminum from 30.7°C to 82,1C?(show your steps)
Answer:
32.4 kJ
Explanation:
Given that:
Specific heat capacity fo copper, c = 0.9
Mass of copper, m = 700 g
Temperature change, dθ ;t2 - t1 = (82.1 - 30.7) = 51.4
Energy required, E = mcdθ
E = 700 * 0.9 * 51.4
E = 32382 J
Energy required on kJ
32382 / 1000
= 32.382 kJ
= 32.4 kJ
______ occur between molecules that have permanent intramolecular differences in elecronegativity.
A. Dipole-dipole interactions
B. Dispersion forces
C. Hydrogen bonds
Answer:
Dipole-dipole interactions
Explanation:
What is 6.25 in scientific notation?
Is the number of total molecules on the left side of a balanced equation always equal to the number of total molecules on the right side of the equation
Answer:
No
Explanation:
No, but the total mass of reactants must equal the total mass of products to be a balanced equation.
Example: Consider the following reaction ...
3H₂ + N₂ => 2NH₃ and 'amu' is atomic mass units (formula weights from periodic table)
In terms of molecules, there are 4 molecules on the left (3 molecular hydrogens (H₂) and 1 molecular nitrogen (N₂) and 2 molecules of ammonia on the right side of equation arrow. ∑reactant molecules ≠ ∑product molecules.
In terms of mass of reactants & mass of products, the 3H₂ + N₂ => 6amu + 28amu = 34amu & mass of products (2NH₃) => 2(14amu) + 6(1amu) = 34amu for sum of product masses.
∑mass reactants = ∑mass products <=> 34amu = 34amu.
The expression '∑mass reactants = ∑mass products' as applied to chemical equations is generally known as 'The Law of Mass Balance'.
When the North Pole of one magnet is next to another North Pole of the other manger they will repel. True or false
Please answer this question
Answer:
K^2O
Explanation:
I remember a question like this one and I got it right its K^2O
(aka its C)
After mixing for three hours, the product is extracted into dichloromethane and the solvent is removed to give 245 mg of an oil. Using the moles of our protected aldehyde calculated earlier (2.96) and the molecular weight of the product (102 g/mol) predict the theoretical 100% yield of the product in milligrams. Round to the tenths place.
Answer:
the theoretical 100% yield of the product in milligrams is 302920 mg
Explanation:
Given the data in the question;
245 mg of an oil
Using the moles of our protected aldehyde calculated earlier (2.96)
the molecular weight of the product (102 g/mol) = 102000 mg/mol
so, the mass of aldehyde produced (100% yield) will be;
⇒ number of moles × molar mass
⇒ 2.96 mol × 102000 mg/mol
⇒ 302920 mol.mg / mol
⇒ 302920 mg
Therefore, the theoretical 100% yield of the product in milligrams is 302920 mg
Which system is affected by the process of weathering?
the hydrosphere
the atmosphere
the biosphere
the geosphere
[tex] \huge \colorbox{pink}{Answer☟︎︎︎}[/tex]
When ice melts, liquid water performs the act of erosion by carrying away the tiny rock fragments lost in the split. This specific process (the freeze-thaw cycle) is called frost weathering or cryofracturing. Temperature changes can also contribute to mechanical weathering in a process called thermal stress.
What atom has the largest atomic radius barium calcium magnesium radium
Answer:
Radium
Explanation:
It has the highest atomic number so it would have more shells, making it larger than the others.
NEEED HELP NOW
A new drug has been released to the public and is popular among
consumers. It is effective in relieving high blood pressure. However, it has
altered some patients' personalities. Which stage of the engineering process
may address this negative side effect?
A. Evaluating test results
B. Looking for improvements
C. Screening
D. Testing
Answer: looking for improvements
Explanation:
Answer:
B. Looking for improvements
Explanation:
took the quiz and got in right on a pex
helppppppppppppppppp
Answer:
b
Explanation:
"A bicycle's brakes apply 299 N of frictional force to the wheels as the bike moves 24 m
for 3.0 s. How much WORK do the brakes do?"
Answer:
0.62 N
Explanation:
first of all: 3.0 s = 0.05 m
Let ? be the work that brakes do at 3.0s
24 m ----> 299 N
0.05 m ---->?
? = (0.05 m x 299 N)/ 24
? = (14.95)/ 24
? = 0.622 N
which property is a property of water
Answer: Polarity, Boiling and Freezing Points, Specific Heat Capacity, Density, Surface Tension, Heat of Vaporization and Vapor Pressure, Capillary Action, Solid State (Ice), Liquid State (Liquid Water), Gas State (Steam),
Explanation: Water molecules are polar, so they form hydrogen bonds. This gives water unique properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion, and density.
What is the molar mass of H2CO3?
(Molar mass of H = 1.0079 g/mol; C = 12.010 g/mol; O = 15.999 g/mol)
Answer:
molar mass of H2CO3 = 72.0228
Answer:
62.02 g/mol
Explanation:
Took the test and got it right. if you have enough faith in brainly youll choose the right answer
what is a 7 letter word that starts with f: Ancient plants and animals formed into rocks.
Answer:
Fossils?
Explanation:
What is the main gas in our atmosphere?
Answer:
Nitrogen
Explanation:
Answer:
Yes, its nitrogen. I wrote my answer earlier in the wrong spot.
Explanation:
The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.
How are fossil fuels formed from geologic processes?
Answer:
Explanation:
Fossil fuels are hydrocarbons, namely, petroleum , coal and natural gas, formed from buried combustible geologic deposits of organic and natural materials. They are created from decayed animals and plants that convert into coal, crude oil or heavy oil due to constant exposure to pressure and heart in the earth’s crust.
The compounds that make up plankton and plants convert into fossil fuels. Plankton decomposes into natural gas and oil, while plants become coal. Nowadays, humans extract these resources through coal mining and the drilling of oil.
What are fossil fuel ?The term fossil fuel is defined as they are made from decomposing plants and animals. An example of a fossil fuel is coal, as well as oil and natural gas.
Because they were generated from the petrified, buried remains of plants and animals that once lived millions of years ago, coal, crude oil, and natural gas are all referred to as fossil fuels.
Thus, The remains of these animals underwent a transformation into what we now know as fossil fuels over millions of years at great pressure and high temperature.
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An example of a suspension is:
A. blood
B. gelatin
C. muddy water
D. milk