Please help is for my final An example of a chemical change is-
evaporation of seawater
о
sublimation of dry ice (CO2)
melting of aluminum
burning wood reducing it to ashes
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Explanation:
Souring of milk
Baking of cake
Related Questions
12. A. 2 g of ferrous sulphate crystals 5 points
are heated in a dry boiling tube. a)
Name and define the type of reaction
that has taken place. b) Write
balanced chemical equation for the
above reaction. c) List two main
observations of this reaction. B. A
shining metal 'M'on burning gives a
dazzling white flame and changes to
a white powder ‘N’. a) Identify ‘M'and
'N'. b) Name the type of reaction
taking place and write the balanced
chemical equation.
Answers
Answer:
A) Decomposition reaction.
Decomposition reaction is defined as a chemical reaction whereby a compound is broken down into 2 or more simpler substances.
B) 2FeSO4 + Heat > Fe2O3 + SO2 + SO3
C) - Gas evolution because a gas is part of the product
- Upon heating its colour gradually changes from pale green to reddish brown which implies a change in state
Explanation:
A) Name of the reaction is; Decomposition reaction.
Decomposition reaction is defined as a chemical reaction whereby a compound is broken down into 2 or more simpler substances.
B) The balanced chemical equation is;
2FeSO4 + Heat > Fe2O3 + SO2 + SO3
C) From experience, the 2 main observations of this reaction are;
- Gas evolution because a gas is part of the product
- Upon heating its colour gradually changes from pale green to reddish brown which implies a change in state.
PLEASE HELP ME If a radioactive substance has an initial mass of 50 grams
and its mass halves every 5 years, what is the number of
grams remaining after 20 years?
Answers
Answer: [tex]3.125\ g[/tex]
Explanation:
Given
Initial mass [tex]A_o=50\ g[/tex]
half-life is [tex]T_{\frac{1}{2}}=5\ years[/tex]
At any time the left amount is given by
[tex]A=A_o2^{-\dfrac{t}{T_{\frac{1}{2}}}}\\\\\text{Insert the values}\\\\A=50\cdot 2^{-\dfrac{20}{5}}\\\\A=50\cdot 2^{-4}\\\\A=\dfrac{50}{16}\\\\A=3.125\ g[/tex]
Which of the following statements is true?
A- Chemical digestion includes the physical breakdown of chunks of food.
B- Mechanical digestion begins in the mouth, and includes the tearing and grinding of food with teeth.
C- Mechanical digestion uses teeth to grind food and saliva to moisten the food
making it easier to chew.
D- Chemical digestion includes the chemical breakdown of food and mixing of the food particles with the help of the tongue
Answers
B- Mechanical digestion begins in the mouth, and includes the tearing and grinding of food with teeth.
C- Mechanical digestion uses teeth to grind food and saliva to moisten the food
making it easier to chew.
These points are true.
Natalia dipped two feathers in oil. Then she dipped one feather in cold water and the other feather in hot water. She swirled both feathers around for 20 seconds, then removed them. Her results are in the table. Cold Water Hot Water Before Oil After Oil After Water Before Oil After Oil After Water Mass 1.2 g 4.5 g 4.2 g 1.2 g 4.4 g 3.5 g She also took a picture of each feather after swirling it in water. two feathers, each with oil and beads of water Was either the cold water or the hot water able to remove the oil? Explain your reasoning.
Answers
Answer:
The hot water was better for removing the oil.
Explanation:
You can see that because the mass went down more with the hot water. So, that means that more oil was taken out of the feather with hot water.
Answer:
The mass changed from 1.1grams to 4.5 grams. The appearance is another thing that changed when it got dipped in oil. The feather look like it lost some feathers or the feathers became transparent. The feather just looks soggy and heavier overall. I believe that if Natalia dips the feather covered in oil in cold water, the feather will remain the same. If she were to dip it in hot water, the feather will get rid of the oil mostly. Think about it, in the ocean the water is cold right? So when oil spills in the ocean it will stay there. Hot water is the best to remove the oil from the feather.
Explanation:
Hopefully this will help.
Which of the following is an acid-base neutralization reaction?
A
Mg + 2 HCl → MgCl2 + H2
B
SiCl4 → Si + 2 Cl2
C
AgNO3 + KCl → AgCl + KNO3
D
HCl + KOH → KCl + H2O
Answers
Answer:
D
Explanation:
The reaction in which an acid reacts with a base to form salt and water is called acid base reaction.
here, HCL ( strong acid) reacts with KOH (strong base) and KCL (salt) and H2O (water) is formed.
The reaction between HCl and KOH is an example of acid-base neutralization reaction. Thus, the correct option is D.
An acid-base neutralization reaction refers to the reaction between an acid and a base that react to form a corresponding salt and water.
The anion from the acid and the cation from the base combine to form the salt. In this case, chloride ions (Cl⁻) and potassium ions (K⁺) combine to form the salt potassium chloride (KCl).
Salt formation leads to neutralization of the charge in the molecule, and also, the pH of the solution gets neutralized whose extent depends upon the strength of the acid and base used.
The hydrogen ions (H⁺) from the acid and hydroxyl ions (OH⁻) from the base combine to form water.
Learn more about acid-base neutralization in:
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what is the molarity of a solution prepared dissolving 317 g of CaCl2 into enough water to make 2.50 L of solution?
Answers
Answer:
1.14 M
Explanation:
Step 1: Calculate the moles corresponding to 317 g of calcium chloride (solute)
The molar mass of calcium chloride is 110.98 g/mol.
317 g CaCl₂ × 1 mol CaCl₂/110.98 g CaCl₂ = 2.86 mol CaCl₂
Step 2: Calculate the molarity of the solution
Molarity is equal to the moles of solute divided by the liters of solution.
M = moles of solute / liters of solution
M = 2.86 mol / 2.50 L = 1.14 mol/L = 1.14 M
Which statement describes the Richter scale?
It cannot account for fault movement during an earthquake.
It measures large earthquakes far from the seismograph.
It estimates the total energy released from an earthquake.
It increases in magnitude as amount of damage increases.
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Answer:
It measures large earthquakes far from the seismograph.
Explanation:
It uses a seismograph to measure earthquakes far from the seismograph where seismic waves are used to determine the magnitude of an earthquake.
Answer: d. It increases in magnitude with an increase in size of seismic waves.
Explanation:
how many layer does the earth have?
Answers
Answer:
The earth is split into four major layers: the crust, the mantle, the outer core and the inner core
Explanation:
The equilibrium of 2H2O(g) 2H2(g) + O2(g) at 2,000 K has a Keq value of 5.31 x 10-10. What is the Keq expression for this system?
A) [H2}^2[O2} / [H2O]^2
B) [H2][O2] / [H2O]
C) [H2O]^2 / [H2]^2[O2]
D) [H2O]^2 / [H2][O2]
Answers
Answer:
B
Explanation:
I don't know how to explain this but you get it
What is the pressure of the gas if we have 3.50 moles of helium at -50.0°C
in a rigid container whose volume is 25.0 liters?
003 kPa
-58.2 kPa
259.6 kPa
0.0 kPa
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Answer:
259.6kPa
Explanation:
because it is big
Which heat source is most directly connected to the seasons?
Answers
Answer:
the solar heat source from the sun is what gives us most of the heat
Explanation:
How is entropy related to the spontaneity of a reaction? AP3X
Answers
Answer:
S>0 contributes to spontaneity.
Explanation:
i just took the test on a pex :)
According to the law of thermodynamics, the relationship between entropy and the spontaneity of a reaction is S > 0.
What is entropy?Entropy is the total amount of energy in a closed system that is present there, but there are no uses for that energy. It is the unused energy for any work.
By the second law of thermodynamics, any spontaneous process results in an increase in the universe's overall entropy. The total of the entropy produced by the spontaneous process and the change in energy brought on by the heat flow is known as the net change in entropy of the system or S.
The reaction will be spontaneous if the delta G is negative. Delta G is the Gibbs free energy. So the entropy S will be greater that the reaction.
The Gibbs free energy equation is:
△G = △H − T△S
Thus, the relation is S > 0.
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If 2.28 g C8H18 reacts with 7.00 g of Oz, predict the mass of CO, that can be produced and
identify the limiting reactant. Explain how you got your answers.
Unbalanced equation: C8H180 + 026) • CO26) + H₂O
Answers
Answer:
O₂ is limiting reactant and 6.17g CO₂ can be produced
Explanation:
Based on the balanced reaction:
C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O
1 mole of C₈H₁₈ reacts with 25/2 moles O₂.
To solve this question we must convert the mass of each reactant to moles and, using the balanced reaction, we can find limiting reactant. With moles of limiting reactant we can find the moles of CO₂ and its mass as follows:
Moles C₈H₁₈ -Molar mass: 114.23g/mol-
2.28g * (1mol / 114.23g) = 0.0200 moles C₈H₁₈
Moles O₂ -Molar mass: 32g/mol-
7.00g * (1mol / 32g) = 0.219 moles O₂
For a complete reaction of 0.0200 moles C₈H₁₈ are needed:
0.0200 moles C₈H₁₈ * (25/2moles O₂ / 1mole C₈H₁₈) = 0.250 moles of O₂ are needed.
As there are just 0.219 moles, O₂ is limiting reactant.
Moles of CO₂ that can be produced:
0.219 moles O₂ * (8moles CO₂ / 25/2moles O₂) = 0.140 moles CO₂
The mass is -Molar mass CO₂: 44.01g/mol-:
0.140 moles CO₂ * (44.01g / mol) =
6.17g CO₂ can be producedAlguien sabe como puedo saber si la bebida (gaseosa) al contener agua carbonatada, ¿esta pasa por electrolisi?, ya que el H2O, podria ser que puede ser de reaccion de sintesis, que seria H2+02------>H20? Seria hidrogeno gaseoso y pxigeno gaseoso formaria el agua carbonatada?, ayuda tengo esta duda >_
Answers
Answer:
Por formación de burbujas.
Explicación:
La presencia de burbujas en la superficie de la bebida ayuda a determinar si la bebida tiene gas carbonatado o dióxido de carbono. El gas de dióxido de carbono no se puede mezclar con agua ni disolver en agua normalmente. Se puede agregar mediante alta presión al agua para que cuando se coloquen en condiciones normales, el dióxido de carbono se libere en forma de burbujas. No, el gas hidrógeno y el gas hidrógeno no podrían formar agua carbonatada porque ambos son átomos diferentes. El agua carbonatada tiene gas dióxido de carbono, no gas hidrógeno.
Can someone help me with these answers please I’ll give Brainly !!!!
Answers
1.What's the first thought that comes to mind when you hear "nuclear"? nuclear, that's the word. well the first thing that comes into everyone's mind in nuclear and they have to think it then think of words that associate with it.
2.the most important point of something.
3.test site
4.
Write the formulas for the following compounds :
Sodium phosphate
Phosphorus triiodide
Answers
phosphorus triiodide = PI3
hope this helps. make brainliest please!
Explanation:
1.Na3PO4
2.PI3
therefore this is the formula for sodium phosphate and phosphrous triiodide
Deforestation is the act of destroying forests so the land can be used for other purposes. Do you think deforestation increases, decreases, or has no effect on the biodiversity of the forest ecosystem? Explain your answer.
Answers
Answer:
deforestation decreases biodiversity of the forest ecosystem
Explanation:
Deforestation has to do with the process of felling trees. This process destroys forest ecosystems. Deforestation is normally carried out for the purpose of development.
An ecosystem is a self supporting unit in which living and non living things interact. The different species of plants and animals found in an ecosystem is called biodiversity.
Since organisms in an ecosystem interact among each other and with their non-living environment, destruction of the trees in the forest ecosystem leads to the loss of certain species present in the ecosystem.
For instance, climbers and animals found on tree tops are normal components of a forest ecosystem. When trees are felled and the forest ecosystem is destroyed across the world, these organisms are threatened. This leads to loss of species or loss of biodiversity.
Answer:
Here’s one possible answer:
Deforestation will likely decrease the biodiversity of the forest ecosystem. It reduces the living space and food sources for some of the organisms. Scarcity of space and food may be a threat to the population of those organisms. Over time, some species may die off, leaving fewer species in the forest.
Explanation:
Describe how the Sun and Earth formed.
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Answer:
When the solar system settled into its current layout about 4.5 billion years ago, Earth formed when gravity pulled swirling gas and dust in to become the third planet from the Sun. Like its fellow terrestrial planets, Earth has a central core, a rocky mantle and a solid crust.
Which is an example of cooperation?
individual ants together make up an ants’ nest
when an organism is more successful at hunting than another
when an organism finds a new way to get itself water
when people get together to stop the killing of the hawks, skunks, and weasels
Answers
2
A chart with the densities of four metals is shown.
Metal
Density (gicm')
Titanium
4.5
Zinc
7.1
Nickel
88
Silver
10.5
Students were given a sample of an unknown metal and told to determine
its density. They measured its mass as 26.4 g and its volume as 3.0 cm?
Use the chart to determine which metal the students were given.
Answers
Answer:
mass(m)=26.4g
volume (v)=3.0cm²
we have
density =m/v=26.4/3=8.8g/cm³
since it is equal to density of nickel.
Option C nickel is a required answer.
Answer:
[tex]\huge\boxed{\fcolorbox{green}{yellow}{option \: \: c}}[/tex]
A gas has a temperature of 14 °C, and a volume of 4.5 liters. If the temperature is raised to 29
°C and the pressure is not changed, what is the new volume of the gas
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The new volume of the gas wii be 4.7 liters.
If a book has a weight of 23.2 N on Earth, what is its mass?
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Answer: Mass is 2,37 kg
Explanation: Weight G = mg, and g = 9.81 m/s² on Earth.
m = W/g = 23.2 N / 9.81 m/s²
20. Which of the following is the correct name for N205?
O nitrate oxide
O dinitrogen pentoxide
O nitrous oxide
O nitrogen dioxide
Answers
Answer:
B!
Explanation:
Di stnds for 2 (N2)
pent = 5 (05)
When 0.875 g. of magnesium was heated in air, 1.25 g. of magnesium oxide
(MgO) was produced. How much oxygen must be added?
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Answer:
1. What is the coefficient for calcium in the balanced equation?
2 Ca + 5 NaOH → 4 Na + 2 Ca(OH)2
2. The burning of 20.0 g of acetylene (C2H2) produces what mass of carbon dioxide? You must
write the equation, balance it and solve the mass-mass problem.
a. Balanced equation:
2 C2H2 + 5 O2 4 CO2 + 2 H2O
Explanation:
Is this correct??Pls help!!!
Answers
Answer:
C
Explanation:
Answer:
Yes, your answer is correct. B is correct :3
Water and oil are "immiscible", meaning they do not mix but stay
separated when combined in a glass. What is the best explanation for this?
1.both are polar molecules
2.both are nonpolar molecules
3.water is a polar molecule and oil is a nonpolar molecule
4.water and oil are both compounds
Answers
Answer:
Good luck man
Explanation:
Good luck man
How much Pb(NO3)2 would need to be added to 100 mL of water to make a saturated solution at 40°C.
Answers
Answer:
70g of Pb(NO3)2 would need to be added
Explanation:
As you can see in the solubility graph of lead nitrate, Pb(NO₃)₂, the solubility of this salt (That is, the maximum amount of the salt that can be dissolved in 100g of the solvent producing a homogeneous solution) is 70g in 100g of water = 70g of the salt in 100mL of water.
A saturated solution is also defined as solubility: The maximum amount of a solute that can be dissolved in a solvent.
That means:
70g of Pb(NO3)2 would need to be added
If the half-life of a radioactive substance is 500 million years and you have 48 atoms of it, how many half-lives will have passed by the time that 6 atoms of the substance remain?
O A. 3
O B. 2
O C. 4
O D. 5
Answers
Answer: 3
Explanation:
What is the definition of bond (in chemistry) ?
Answers
Answer:
Bond is a force that binds two atoms together.
Help please At which boundary type would mountains, such as the Himalayans, most likely form?
Question 6 options:
Divergent
Convergent
Transform
Slip Fault
Answers
Answer:
convergent is the answer