Which two observations are evidence that a chemical change is happening?
A. A yellow liquid forms as a yellow solid is slowly heated.
I B. Bubbles of gas are released when a solid is combined with a
liquid.
I c. Solid crystals form as the temperature of a liquid is lowered.
D. Light and heat are given off after a spark ignites a substance,
Hurry. NO Spam! Write the neutralization reaction that occurs between HF and LiOH.
Answer:
HF + LiOH = LiF + H2O.
Explanation:
Hydofluoric acid is a weak acid the solution would be slightly basic due to the following equilibrium (condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs.)
Hope that helps. x
Does pure water conduct electricity? If not, what can we do to make it conduct electricity?.
Pls Help Me (20 Points)
In one to two sentences, explain how to compare the strength of electrostatic forces between molecules in salt water to the strength of electrostatic forces between molecules in freshwater. Include a description of the data to be collected and how that data would allow one to draw conclusions about the relative strengths of the electrostatic forces in the two substances.
Answer:
-Salts are composed of ions that form a tightly packed and ordered network, which is called a crystal lattice, and it is held together by ionic bonds.
Explanation: salts are ionic compounds, which are composed by oppositely charged ions (cations and anions) which are bonded each other by ionic bonds, in an ordered arrangement, often a crystalline solid.
-When a salt is added to a polar solvent like water, the ions interact with the solvent molecules via ion-dipole forces, which overcome the forces originally holding the ions together.
Explanation: the molecules of a polar solvent are dipoles because they have dipolar momentum (a difference in charge due to a electronegativiy difference). When a salt is dissolved in a polar solvent, it dissociates in ions. So, the resulting interactions between these species are ion-dipole forces.
-The ions are then isolated and stabilized in solution via these interactions, and when this occurs for most of the salt compound, it is considered soluble in that solvent.
Explanation: the ions in solution are surrounded by solvent molecules which stabilizes them. A salt which is enterely dissolved in a solvent is soluble in that solvent.
-Due to the nature of the interaction between ions and solvent molecules, a concentration of ions can be dissolved higher in water than in alcohol.
Explanation: water molecules have unique properties that make water an universal solvent. Due to these properties and its polarity, water can dissolve larger quantities of salt than other polar solvents such as alcohol.
The electrostatic force in water without salt is stronger as compared to the water due to the presence of free electrons.
In water hydrogen bonding is present that is the only kind of electrostatic force present in the water. In water containing salt sodium and chloride ions are present which conduct strong electrostatic force. A static meter is ideal for measuring the of liquids. It measures the charge on the liquid. Hence, the electrostatic force in salt water is stronger as compared to the water due to the presence of free electrons.Learn more about electrostatic:
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Draw the Complete Electron Energy Level Diagram (or the Orbital Diagram) for Ru+3
Answer:
A
Explanation:
refer to textbook
predict the product 1-bromo propane is treated with sodium metal
When 1-bromo propane is reacted with sodium metal, the propane and sodium bromide are formed.
Propane and sodium bromide are produced when the 1-bromo propane is reacted with sodium metal. The Bromine which is present in the 2-bromopropane is removed through hydrogenation and combines with the sodium metal which results in the production of propane and sodium bromide.So we can conclude that propane and sodium bromide are produced when the 1-bromo propane is reacted with sodium metal.Learn more about 1-bromo propane here: https://brainly.com/question/25597694
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help i cant do this i need this ASAP
Answer:
you draw the line first to the light bulb and then you connect it to the battery then you connect it to microscope
Explanation:
hope this helped pls mark it brainlest pls and thank you:)
who is credited with developing the periodic table
Answer:
Dimitri mendleev and Albert something. I forgot his last name. I think ghorso. Albert ghorso.
Do you think the amount of fat will affect its melting point?
Can anyone help me? I will try to give brainliest.
Answer:
Looking at the table, Silver is definitely the most conductible metal there. It has the lowest electrical resistivity which means it allows for an easier flow of electrons, and it also has a higher thermal conductivity which means it would exhibit a higher conductivity. Diamond has the highest thermal conductivity, but the electrical resistivity is extremely high and due to its giant covalent/tetrahedral molecular structure (being an allotrope of Carbon), electrons can't necessarily jump around. Diamond wouldn't be a conductor at all.
The most simplest composition and structures provide a higher thermal conductivity. For example, with Diamond, we know that it is a structure made of covalent bonds of carbon, so its thermal conductivity is high.
Answer:
Q1
Copper
Explanation:
Copper is a good conductor of electricity, its resistance is high, and its chemical activity is weak
Q2
The thermal conductivity of a specific material is highly dependent on a number of factors. These include the temperature gradient, the properties of the material, and the path length that the heat follows.
Read the following chemical equations.
Reaction 1: 2KI + H2O2 2KOH + 12
Reaction 2: Cl2 + H2 → 2HCI
Which of the following statements is true for both the chemical equations?
A. I is oxidized in reaction 1 and Cl2 is oxidized in reaction 2.
B. I is reduced in reaction 1 and Cl2 is reduced in reaction 2.
C. I is oxidized in reaction 1 and Cl2 is reduced in reaction 2.
D. I is reduced in reaction 1 and Cl2 is oxidized in reaction 2.
This problem is providing two reduction-oxidation (redox) reactions in which the oxidized and reduced species can be identified by firstly setting the oxidation number of each element:
Reaction 1: 2K⁺I⁻ + H₂⁺O₂⁻ ⇒2K⁺O⁻²H⁺ + I₂⁰
Reaction 2: Cl₂⁰ + H₂⁰ ⇒ 2H⁺CI⁻
Next, we can see that iodine is being oxidized and oxygen reduced in reaction #1 and chlorine is being reduced and hydrogen oxidized in reaction #2 because the oxidized species increase the oxidation number whereas the reduced ones decrease it.
In such a way, the correct choice is C.
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(Redox reactions) https://brainly.com/question/13978139Which statement best defines kinetic energy? A. kinetic energy is highest at the highest point of structure or model.
B. kinetic energy is stored in a battery.
C. kinetic energy is energy that is stored up. D. kinetic energy is the energy of motion. help me pls!!
Answer:
The answer is D. Kinetic energy is the energy of motion.
Pls mark brainliest. Hope this helped. :D
5. Scientists always develop a plan when they try to learn something about our natural world. Which
sequence correctly shows the steps scientists follow in their plan?
A. make observations, develop an idea, obtain evidence, suggest an explanation
B. obtain evidence, suggest an explanation, develop an idea, make observations
C. suggest an explanation, obtain evidence, make observations, develop an idea
D. develop an idea, suggest an explanation, obtain evidence, make observations
Which statement describes how a substance melts?(1 point) Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other.
Answer:
Molecules in the substance gain kinetic energy and then become less tightly bound to each other.
Explanation:
According to the forces of attraction , for a substance to melt molecules in the substance gain kinetic energy and then become less tightly bound to each other.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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What is the dependent variable in this graph
Answer:
height (mm)
Explanation:
The independent variable belongs on the x-axis (horizontal line) of the graph, and the dependent variable belongs on the y-axis (vertical line).
BRAINLIEST TO FIRST RIGHT ANSWER
Use the key above to interpret the following incomplete chemical reaction.
Select the statements at apply in order to complete the model. (Choose 3)
A) The number of atoms in the products must be equal to the reactants.
B) One diatomic oxygen should be removed from the reactant side.
C) One unbonded carbon atom should be added to the product side of the equation
D) One carbon atom and two oxygen atoms are needed to balance the equation.
E) One carbon dioxide molecule should be added to the product side of the equation.
Answer:
Carbon dioxide molecule
Answer:a , d ,e
Explanation:
jusy took quiz
Which of the following is not a use of radioactive isotopes?
a) Energy generation
b) Carbon dating
c) Chemotherapy
d) Radiotherapy
Answer:
i belive the answer you are looking for is A.. hope this helps!
Explanation:
im not really 100% certain of this answer due to the fact i am a little rusty.
how would you expect the solubility of barium sulfate in pure water to compare to its solubility in 0.10 m nacl
Answer:
barium sulfate is insoluble (unable to dissolve) in water.
the general equation for the reaction between solid barium sulfate and nacl solution is this:
BaSO4 (s) + 2NaCl (aq) --> BaCl (aq) + Na2SO4 (aq)
to sum this up, to compare the solubility,
1. barium sulfate cant dissolve in pure water.
2. barium sulfate dissolves in nacl solution to give aqueous (aq) barium chloride (bacl) and aqueous sodium sulfate (na2so4), as shown in the equation above.
good luck!
The solubility of barium sulfate in pure water to zero as compare to the solubility in NaCl solution.
What is solubility?
Solubility is a property of any substance that defines how easily can be any substance will get dissolved or show dissolution.
Barium sulphate is insoluble in water beacuse it has higher lattice energy as well as higher size of cations & anions as compare to water, due to which water is not able to attract these ions towards itself affectively.Barium sulphate is soluble in the NaCl solution as this solution having ions which have more power to attract the ions of barium sulphate and show dissolution. Chemical reaction for this will be represented as:BaSO₄ (s) + 2NaCl (aq) → BaCl (aq) + Na₂SO₄ (aq)
Hence, barium sulphate is insoluble in water.
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which describes an attribute of nonrenewable resources
Answer:
atributes of nonrenewable recources are things you cant re use after 1 use like gas
Explanation:
Answer: the answer is b. Are unlimited
Explanation:
Iron reacts with oxygen and water to create rust and hydrogen gas as shown in the chemical equation. What mass of rust, to the nearest hundredth gram, is produced in this reaction?
A) 4.3 g
B) 5.8 g
C) 16.8 g
D) 29.4 g
Answer:
i think its 5.8
Explanation:
Fast pls due rn help fast pls
Answer:
Section a:
1. stratosphere
2. radio waves
3. nitrogen, oxygen
4. humidity
5. smoke, fog
Section b:
1. ozone layer
2. stratosphere
3. carbon dioxide (CO2)
4. smoke
5. tropical areas
Section c:
1. false, it is clear
Hope those help and are all correct
How do you determine the group and period of an element based on its electron configuration?
Answer:
If you are given with the atomic number of an element you can find it's period number and group number. The period number is related to the number of electron occupied shells in the element and the period number is linked to its valence electrons.
Explanation:
hope it helps luv <3
2.3g of sodium metal is burned completely in oxygen of air.
(Na =23, O =16, at STP : 32g of O2 has 22.4L)
Find mass of the obtained oxide?
Find volume of the required air?
Answer:
mass of Na2O= 3.1 grams
volume of O2= 0.56 L
Explanation:
First what you need to do is establish the balanced equation for the reaction that they're giving you. In this case would be:
4Na + O2 > 2Na2O
And then, you can read the stequiometry of the reaction:
4 moles of Na react with one mole of oxygen to produce 2 moles of sodium oxide.
So now you know that you have 2.3 grams of sodium so you have to obtain the quantity of moles that are present in 2.3 grams of sodium. The molar mass the (the grams by which you will have exactly one mole) so all you have to do is divide 2.3g ÷ 23g/mol= 0.1 mol
So here you have 0.1 mol of sodium, and you know for a fact that for each 4 moles of sodium, one mole of oxygen reacts, so you simply divide the quantity of moles of sodium you have by the 4 moles of oxygen present in the balanced equation.
0.1 moles ÷ 4 moles = 0.025.
So for each 0.1 moles of sodium that react, 0.025 moles of Oxygen react.
Now what you need to do is to find the limitant reactor (the reactor that's according to the comparison to the balanced equation is in a smaller ratio to the other element, that would be in excess.
In this case, both elements are in a ratio that respects the balanced equation so neither of them is in excess or is limitant.
Now, to determine the amount of Na2O, you simply know that one mole of oxygen react to produce to moles of sodium oxide, So all you have to do is establish the factor of conversion:
0.025 moles O2 x 2 moles Na2O/ 1 mol O2= 0.05 moles of Na2O
Then you convert that to grams by multiplying 0.05 by the molar mass of Sodium oxide and it will be:
0.05 mol Na2O x 62 g/mol= 3.1 grams of Na2O
Now what you need to do is find the volume by which O2 is reacting in the reaction so you can use the equation of the ideal gas law.
PV=nRT at standard temperature and pressure (273 K and 1 Atm)
P=Pressure
V=Volume
n=Number of atoms
R=constant of gases (0.082 Atm L/ mol K)
T=Temperature
V=nRT/P (because you need to find the volume)
V= (0.025 mol)(0.082)(273 K)/1 atm
V=0.56 L
And there you go :)
30g of glucose and 20 g common salt is dissolved in 500 mL of water to make solution. Calculate the concentration of a (a) glucose and (b) common salt in terms of mass by mass percentage of the solution. (Density of water = 1 g/mL)
Answer:
The answer of a is 5.45% and b is 3.64%
Explanation:
Density of water = 1 g/mL
∴ Mass of water (solvent) = 500 g
Mass of solute (glucose) = 30 g
Mass of solute (common salt) = 20g
Mass of solution = (30 + 20 + 500) g = 550 g
a.)Mass percentage of solution for glucose
= Mass of solute (gucose)/Mass of solution × 100
= 30/550 x 100
= 5.45 %
b.)Mass percentage of solution for common salt
= Mass of solute (common salt)/Mass of solution × 100
= 20/550 × 100
= 3.64 %
Thus, The answer of a is 5.45% and b is 3.64%
-TheUnknownScientist 72
Answer:
5.45%
and
3.64%
hope it's helpful
What are the most of the elements in the periodic table
Answer:
Most of the elements in the periodic table are metals.
Hope that helps. x
Answer:
Here is your answer,mate!
Explanation:
Metals are the most of the elements in the periodic table.
Imagine you have two beakers. Both beakers are filled with the same amount of water. The water in both beakers is the same temperature as well. You add 50 g of Substance A to the first beaker and 50 g of Substance B to the second beaker. After stirring both beakers, there is a small pile of Substance A at the bottom of the first beaker. None of Substance B is visible in the second beaker. Which of the following statements is true?
A. Substance B is not soluble in water
B. Substance A is more soluble in water than Substance B
C. Substance A is less soluble in water than Substance B
D. Substance A is not soluble in water
Substance A is less soluble in water than Substance B.
In this experiment, we can see that small amount of substance A is present at the bottom of the beaker which means that some amount of substance A does not dissolve in water.
While on the other hand, no substance B is present at the bottom of beaker which shows that all the substance B is dissolved in water so we can made a conclusion that Substance A is less soluble in water than Substance B.
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Kingdom:
Domain:
I am made of many cells. My cells have
an organized nucleus, I have two
parents and eat food.
Guess Who?
please help
Answer:
SORRY IM LATE! at least i saw it.
Explanation:
Kingdom is Eucaryota
domain is eucarya
How is the polarity of a bond different from the polarity of a molecule?
Answer:
A polar bond is one where the charge distribution between the two atoms in the bond is unequal. A polar molecule is one where the charge distribution around the molecule is not symmetric. It results from having polar bonds and also a molecular structure where the bond polarities do not cancel.
Explanation:
Which non metal is highly reactive
Answer:
element fluorineThe most reactive nonmetals reside in the upper right portion of the periodic table. Since the noble gases are a special group because of their lack of reactivity, the element fluorine is the most reactive nonmetal.can somebody please help me here ? i wanna make sure of my answer..
Answer:
[Unfortunately] Answer is A
Explanation:
You should know that 'liquid' is a state of matter and aqueous means that there is water present.
-It is mentioned that barium chloride is a solution. So you can cut off the C option.
-Barium sulfate is a salt which means it's a solid, so you can cut off the D option.
We now have A and B as the only options remaining.
-Dilute sulfuric acid is definitely not a liquid because water is present. (dilute indicates that there is a greater proportion of water)
The answer should be A.