What is the density of a book with a mass of 60g and a volume of 20 cm3? *
Answer:
[tex]3 g/cm^{3}[/tex]
Explanation:
Density is a measure of a substance's mass over its volume.
d = m/v
Therefore d = 60g/20cm3 = 3 g/cm3
Use a scientific calculator to calculate [H+] for the following pH values:
7 (a neutral solution)
5.6 (unpolluted rainwater)
3.7 (first acid rain sample in North America)
How many times higher is the concentration of H+ in the Hubbard Brook sample than in unpolluted rainwater?
Answer:
pH = 7 ⇒ [H⁺] = 1.0x10⁻⁷ M
pH = 5.6 ⇒ [H⁺] = 2.5x10⁻⁶ M
pH = 3.7 ⇒ [H⁺] = 2.0x10⁻⁴ M
H⁺ concentration in the Hubbard Brook sample is 80 times higher than in unpolluted rainwater.
Explanation:
To answer this problem we need to keep in mind the definition of pH:
pH = -log[H⁺]Meaning that after isolating [H⁺] we're left with:
[H⁺] = [tex]10^{-pH}[/tex]Now we proceed to calculate [H⁺] for the given pHs:
pH = 7 ⇒ [H⁺] = [tex]10^{-7}[/tex] = 1.0x10⁻⁷ MpH = 5.6 ⇒ [H⁺] = [tex]10^{-5.6}[/tex] = 2.5x10⁻⁶ MpH = 3.7 ⇒ [H⁺] = [tex]10^{-3.7}[/tex] = 2.0x10⁻⁴ MFinally we calculate how many times higher is [H⁺] when pH = 3.7 than when pH = 5.6.
2.0x10⁻⁴ / 2.5x10⁻⁶ = 80Answer:
1. 7 (a neutral solution)
Answer: 10-7= 0.0000001 moles per liter
2. 5.6 (unpolluted rainwater)
Answer: 10-5.6 = 0.0000025 moles per liter
3. 3.7 (first acid rain sample in North America)
Answer: 10-3.7 = 0.00020 moles per liter
The concentration of H+ in the Hubbard Brook sample is 0.00020/0.0000025, which is 80 times higher than the H+ concentration in unpolluted rainwater.
Explanation: -
Which equation is correctly balanced?
A) CaO + 2H2O + Ca(OH)2
B) NH3 + 202 → HNO3 + H20
C) Ca(OH)2 + 2H3PO4 → Ca3(PO4)2 + 3H2O
D) Cu + H2SO4 → CuSO4 + H2O + SO2
CaO + 2H2O + Ca(OH)2 is a balance chemical equation. Therefore, option A is correct.
What is balance chemical equation ?A balanced chemical equation is one that has the same number of atoms of each type in the reaction on both the reactant and product sides. In a balanced chemical equation, both the mass and the change are equal.
When a chemical reaction occurs, the mass of the products should be equal to the mass of the reactants, according to the law of conservation of mass. As a result, the number of atoms in each element remains constant during the chemical reaction. As a result, the chemical equation must be corrected.
The chemical equation is said to be balanced if there are no inequalities. Every element in this example now has an equal number of atoms on both the reactant and product sides.
Thus, option A is correct.
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What is the name of this hydrocarbon?
Answer:In the given molecule the methyl group is attached at the second carbon atom of the parent chain. Therefore the name of hydrocarbon is 2-methylbutane.
Explanation:
Using the figure, angels p and w are example of
Answer :)
Answer:
D
Explanation:
we just did this in class last week haha i know my math :)
What ratio of NaCN to HCN is needed to prepare a pH 9.40 buffer? (Ka of HCN is 4.9 × 10⁻¹⁰)
Answer: The ratio of NaCN to HCN is, 1.26
Present in a state where it molecules are far apart during a change of state it's molecules slow down which change of state has most likely taken place from a gas to a liquid from a liquid to a gas from a solid to a liquid from a gas to a plasma
Answer:
The change of state that has occurred is from a gas to a liquid
Note: The question is incomplete. The complete question is given blow.
H₂O is initially present in a state where its molecules are far apart. During a change of state, its molecules slow down. Which change of state has most likely taken place?
from a gas to a liquid
from a liquid to a gas
from a solid to a liquid
from a gas to a plasma
Explanation:
Water can exists in three states: as gaseous water vapor, as liquid water, and as solid ice. Each of these states of water can be interconverted from one to another by the addition or removal of heat in a process known as change of state.
Liquid water can be converted to solid ice by the removal of heat, while solid ice ice can be converted to liquid water by the addition of heat. Also, liquid water can be converted to water vapor by the addition of heat, while water vapor can be converted to liquid water by the removal of heat.
Of the three states of water, the one in which the molecules are farthest apart is in the gaseous state. The molecules have high kinetic energy and move randomly while colliding with one another. When a heat is removed from these highly energetic molecules, the molecules slow down and lose some of their kinetic energy and a change of occurs from gaseous to liquid state.
Therefore, the change of state that occurred as described, is from gas to liquid.
please everyone do this and send me
Answer: question 2 is (a) (25+273)k=298k(b) (373+273)k=646k
question 5 is 25 degree Celsius
question 1 is
a = (293-273) =20 degree Celsius
b = (470-273)=197 degree Celsius
question 3 is
a = naphthalene ball undergo sublimation due to which it convert directly into vapour and disappear into air without leaving any solid
b = the participle of perfume diffuse rapidly into air and its smell can be felt while sitting serval metre away
question 4 isthe force of allraction between the particles increases as we go from liquid to gas so the required order is : Oxygen< water< sugar
I hope it is helpful to you
Identifying Cell Structures
Which structures are found in plant colls, but not in animal cells? Check all that apply
)
coll wall
coll membrane
chloroplasts
O lysosomes
ribosomes
vacuoles
Answer:
cell wall and chloroplasts
Explanation:
Pleseee help me pretty please ✨
Answer:
6 N.
Every thing has equal and opposite reaction.
Answer:
The answer is C I believe, I do not know for sure but I think that is the answer..
I'm sorry if I'm wrong.
Explanation:
Using the diagram , what is the intersection of plan ABCD and GC?
Answer:
C
Explanation:
When a line segment and a plane intersect, they intersect at a point. They both coincide on point C
Balancing chemical equation:
_Na+_MgF2—>_NaF+_Mg
Na= ? Na= ?
Mg= ? Mg= ?
F= ? F= ?
2Na + MgF2 → 2NaF + Mg
The Earth's early atmosphere consisted of what
A case of paper has a mass of 2000 g. A case of paper contains 10 reams of paper. One ream of paper is 500 sheets. What is the mass, in grams, of 50 sheets of paper?
Answer:
s8sooooosoossososososkdk
18.
react to cause chemical reactions
Protons
Neutrons
Electrons
__Is when water changes from a solid to a liquid
When water changes from a solid to a liquid it is called melting.
Solid ice melts and forms into a liquid: water.
If this incorrect, please, don't refrain to tell me. Thank you.
160
140
120
100
Temperature (°C)
80
60
40
20
0
0
2 4 6 8
10 12 14 16 18 20 22 24 26
Time (min)
.
At what temp will this substance freeze? 70 CV
At what temp will this substance condense? 70 C
How long will it take to release the heat of vaporization? 3 min
What is the melting point? 70 C
In what physical state did this substance end? Gas
All cooling processes, including phase changes, are Exothermic
At 90 C, what phase of matter is this substance? Liquid
Convert 75k to oC
(I’ll mark you as brainlister)
Answer:
-198.15
Explanation:
sorry if wrong form
Which statement correctly describes the relationship between air temperature and air pressure?
-Warm air rises, creating an area of low pressure.
-Cool air sinks, creating an area of low pressure.
-Warm air sinks, creating an area of low pressure.
-Cool air rises, creating an area of low pressure.
Answer:
-Warm air sinks, creating an area of low pressure.
Explanation:
Heat will weigh more, than cool air!
Give one example of
a) Homogeneous mixture of two elements
Answer:
honey
Coffee
blood
Explanation:
These components are uniformly distrubuted and these cannot be seperated unlike heterogeneous
which part of a food chain absorbs the Sun's light and heat
The plants are the part that absorb the Sun's light and heat.
The part of a food chain that absorbs the sun's light and heat is producers that are plants.
What is a food chain?A food chain is the chain that shows the transfer of energy from one part to another.
The bottom of the food chain is the producers that make their own food, then the consumers and the decomposers.
Thus, the part of a food chain that absorbs the sun's light and heat is producers that are plants.
Learn more about food chain
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What is the correct formula for the missing product from the equation below:
Na2CO3(aq)
+
CaCl2 (aq)
> NaCl +
Answer:
CaCO3 (s)
Explanation:
This equation is a double replacement equation, which means that since Na and Cl and paired, Ca and CO3 will be paired.
Then, you look at the charge of each element and balance
Ca has a 2+ charge
CO3 has a 2- charge
The 2+ charge and the 2- charge will cancel so there is no need for a subscript or to balance the equation
The complete equation will be Na2CO3 (aq) + CaCl2(aq) -> NaCl (aq) + CaCO3 (s)
I hope this helps and have a great day!
The diffusion of matter and energy in a liquid is slower than diffusion in a gas
True
O False
Which characteristic of a planet describes whether the planet has a thick or thin layer of gas?
Atmosphere
Moons
Rings
Surface composition
Answer:
Atmoshphere!
Explanation:
I took the test and got a 100%! :) Hope this helps, plz mark brainliest!
If you have 12 atoms of hydrogen before a chemical reaction, how many atoms of hydrogen will be present
Answer:
12 atoms of hydrogen will be present in the product
Explanation:
12 atoms of hydrogen will be present in the product because the law of conservation of mass states that mass is neither created nor destroyed in chemical reactions.
The law of conservation states that the mass of the element remains the same during the course of the reaction.
The law of reaction conformed by the following:-
Mass of reactant Mass of productAccording to the question, the amount of hydrogen is 12 atoms in the reactant and the amount will remain the same at the end of the reaction, which is a product that is 12 atoms
Hence, the amount remains the same in the reaction that is 12 atoms
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Why do power plants emit such a high percentage of pollutants?
They burn fossil fuels, which releases huge amounts of sulfur dioxide and nitrogen oxide that pollute the air. ... Two thirds of all sulfur dioxide and more than one third of all nitrogen oxides that pollute the air.
3) Explain why elements in the same group
similar properties
Answer:
The elements of the same group have the same number of valence electrons, that is why they have similar properties
in today's pandemic,how can you protect our ozone depletion?
Answer:
if you want to protect our ozone depletion you have aerosol products that don't contain HCFCs and CFCs as stimulus or incitement
Explanation:
why you should use aerosol because when the liquid mixture is freeded or released from the aerosol the liquid propellant becomes a gas so this can easily break up the product into a fine haze or a mist hope its helpful have a good luck
Classify the following as a chemical or physical property: Iron melts at 1535 degrees C. chemical or psychical?
Answer:
Physical property
Explanation:
Change in state is a physical property of matter.
how many mols are in 100.g of Fe?
Answer:
1.79 moles
Explanation:
1.79 moles
1.79 moles
1.79 moles
1.79 moles
Answer:1.79 moles
1.79 moles are there in 100g of iron.
Explanation:
thats the answer for it