Answer:
Ionic compounds generally form between elements that are metals and elements that are nonmetals. For example, the metal calcium (Ca) and the nonmetal chlorine (Cl) form the ionic compound calcium chloride (CaCl2). In this compound, there are two negative chloride ions for each positive calcium ion
Please help with at least one of these questions! I have about 15-20 mins left :(
1. Name 2 examples of a physical change and tell why they are physical changes and not chemical changes.
2. Name 2 examples of a chemical change and tell why they are chemical changes and not physical changes.
3. Gold and pyrite (fool's gold) cannot easily be distinguished by color? What other physical property/properties can be used to tell the 2 metals apart from one another?
Answer:
1. Melting ice does not change the composition of the water or ice, as the ice is only changing its state from solid to liquid. Boiling water also does not change the composition of the water or gas, as the water is only changing its state from liquid to gas.
2. Burning paper turns the paper fibres to ashes. Making yoghurt from milk is making something new out from milk, where there is fermentation going on to turn the lactose into an acid, resulting in a chemical change and not a physical change.
Explanation:
A chemical change is when a new substance is formed from the old thing due to a chemical process such as burning where energy is given off or absorbed, while a physical change is basically changing the state of a substance but its composition does not change, unlike a chemical change.
50 pts
With 11 electrons how many electron shells does sodium have?
3
4
2
1
Answer: 3
Explanation:
What is the tightly stretched membrane that forms the entrance to the middle ear called?
Answer:
I'm so happy to help you with this question!! The answer is tympanic.
Explanation:
The middle ear is separated from the outer ear by the eardrum, or tympanic membrane, a thin piece of tissue stretched tight across the ear canal. Sounds hit the eardrum, making it move.
I really hope this helps you!! :)
How would you put this word equation into a balanced chemical equation: Aluminum nitrate reacts with potassium sulfate to produce aluminum sulfate and potassium nitrate.
Answer:
2Al(NO_{3} )_{3} + 3K_{2}SO_{4} ----> Al_{2}(SO_{4})_{3} + 6KNO_{3}
Explanation:
[tex]2Al(NO_{3} )_{3} + 3K_{2}SO_{4} ----> Al_{2}(SO_{4})_{3} + 6KNO_{3}[/tex]
The elements in Groups 1 and 2 get more reactive as you go down the group.
This means that _______________ is more reactive than lithium and ____________________ is more reactive than beryllium.
Answer:
Sodium and Magnesium
Explanation:
The elements in Groups 1 and 2 get more reactive as you go down the group.
This means that Sodium is more reactive than lithium and Magnesium is more reactive than beryllium.
On the periodic table, as you go down the group, the reactivity of an element increases. Especially with metals in group 1 and 2. Now Lithium is a metal of group 1, followed by Sodium, while Beryllium is a metal in group 2, followed by magnesium. That's how I picked the answers
In contact freezing _____ are used for _____ freezing of foods
immersion -- cryogenic liquids
refrigerants -- immersion
immersion -- refrigerants
cryogenic -- immersion
Answer:
In contact freezing refrigerants are used for immersion freezing foods.
Explanation:
3) What is the mass of a sample consisting of 1.00 X 1022 formula units of MgSO.?(
number of moles = 1.00 X 10^22 ÷ 6.022 × 10^23
= 0.0166 moles
mass = number of moles × molar mass
= 0.0166 × 120.37 = 2.00 g
What property of water enables ice wedging to break rock?
A.
Water is a polar molecule.
B.
Water contains oxygen.
C.
Frozen water takes up more space than liquid water.
D.
Each water molecule contains 18 electrons.
Answer:
c
Explanation:
hope I helped
hope im corrext
Ice wedging can be defined as the property of frozen water to take more space than liquid water. Thus, option C is correct.
The ice has been the solid state of water. The liquid molecules bond together for the resulting solid molecule.
Ice wedging can be defined as the mechanical weathering of the rock by the effect of ice. The rocks have consisted of cracks that accumulated water in them.
With the decrease in the temperature, the water has been expanded and has been converted to ice. The expansion of water in the cracks results in the breaking of the rocks.
Thus, ice wedging can be defined as the property of frozen water to take more space than liquid water. Thus, option C is correct.
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What is true about uranium atoms
Answer:
They have the same number of protons. Scientists are working wit a liquid that is made of only one type of atom.
GOOD LESSONS ♡
What is the mole fraction of NaOH in
an aqueous solution that contains
15.0% NaOH (weight/weight %)?
Molar Mass
NaOH: 39.998 g/mol
H2O: 18.016 g/mol
Answer:
The more fraction NaoH is 39.998g/mol
Answer:
.0735 is correct
Explanation:
The accepted value is 29.35. Which correctly describes this student's experimental data?
Answer:
- Both accurate and precise.
Explanation:
The experimental data is characterized as the data that is generated through a specific test or measurement with the purpose of analysis or evaluation. As per the question, the minuteness of the given data(29.27, 29.32, and 29. 27)most aptly describes that the experimental data collected by the student possesses 'accuracy and precision' apt and specific. It would yield the most worthy and reliable conclusion.
Explain how the ability of dilute sulphuric (vi) acid to conduct an electric current compares with that of concentrated sulphuric (vi) acid
Answer:
Explanation:
Hnsnsnsnsnqnananana
How many Joules of heat will be given off by 55.0g of water as it cools from 87.3°C to 25.0°C?
Answer:
Q = -14322.77 J
Explanation:
Given data:
Mass of water = 55.0 g
Initial temperature = 87.3°C
Final temperature = 25.0 °C
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.0 °C - 87.3°C
ΔT = - 62.3 °C
Q = 55.0 g×4.18 J/g.°C × - 62.3 °C
Q = -14322.77 J
A rotameter calibration curve (flow rate versus float position) obtained using a liquid is mistakenly used to measure a gas flow rate. Would you expect the gas rate determined in this manner to be too high or too low?
Answer:
I would expect the gas rate determined in this manner to be too low
Explanation:
A Rotameter can be designed to respond to the sensitivity of density, velocity, to measure the flow rate of liquid or gas enclosed in a tube. Liquids are denser than gas, and since the gas rate to be determined needed to respond to the velocity head alone of the rotameter so as to bring the forces in the tube equilibrium. Knowing if there is no flow, then the float would remain at the bottom, so gas has to flow at a higher rate compared to the liquid so the float would be in a similar position making it easier to measure the flowrate. This leaves the gas rate to be determined too low.
what the formula of bisethylenediphosphinecobalt(lll)-meu-imido-meu-
hydroxobisbipyridinecobalt(lll) ion.
Calculate the mass in grams of each of the followinga. 5.94 x 10^20 H2O2 moleculesb. 2.8 x 10^22 SO2 moleculesc. 4.5 x 10^25 O3 moleculesd. 9.85 x 10^19 CH4 molecules
Answer:
[tex]0.0335\ \text{g}[/tex]
[tex]2.978\ \text{g}[/tex]
[tex]3586.84\ \text{g}[/tex]
[tex]0.0026\ \text{g}[/tex]
Explanation:
Mass in grams is given by
[tex]m=\dfrac{nM}{N_A}[/tex]
where
n = Number of molecules
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}\ \text{mol}^{-1}[/tex]
M = Molar mass of molecule
Molar mass of [tex]H_2O_2[/tex] = 34.0147 g/mol
[tex]n=5.94\times 10^{20}[/tex]
[tex]m=\dfrac{5.94\times 10^{20}\times 34.0147}{6.022\times 10^{23}}\\\Rightarrow m=0.0335\ \text{g}[/tex]
Mass of [tex]H_2O_2=0.0335\ \text{g}[/tex]
Molar mass of [tex]SO_2[/tex] = 64.066 g/mol
[tex]n=2.8\times 10^{22}[/tex]
[tex]m=\dfrac{2.8\times 10^{22}\times 64.066}{6.022\times 10^{23}}\\\Rightarrow m=2.978\ \text{g}[/tex]
Mass of [tex]SO_2=2.978\ \text{g}[/tex]
Molar mass of [tex]O_3[/tex] = 48 g/mol
[tex]n=4.5\times 10^{25}[/tex]
[tex]m=\dfrac{4.5\times 10^{25}\times 48}{6.022\times 10^{23}}\\\Rightarrow m=3586.84\ \text{g}[/tex]
Mass of [tex]O_3=3586.84\ \text{g}[/tex]
Molar mass of [tex]CH_4[/tex] = 16.04 g/mol
[tex]n= 9.85\times 10^{19}[/tex]
[tex]m=\dfrac{9.85\times 10^{19}\times 16.04}{6.022\times 10^{23}}\\\Rightarrow m=0.0026\ \text{g}[/tex]
Mass of [tex]CH_4=0.0026\ \text{g}[/tex]
what are the harmful effects of water pollution
Answer:
- Reduced biodiversity
- Health problems from drinking the water
- Diseases
There are various types of pollution like air pollution, water pollution , noise pollution etc. Therefore, in below given ways we can see harmful effects of water pollution.
What is pollution?The introduction of hazardous elements into the environment is pollution. Pollutants are the name for these dangerous substances. They can also be brought by by human activities, such as factory runoff or waste.
Following are a few harmful outcomes of water pollution: The health and existence of humans, animals, and plants are all negatively impacted by water pollution. Because it harms crops and soil fertility, polluted water is also bad for agriculture. Ocean life suffers as a result of ocean water pollution.
Therefore, in above ways we can see harmful effects of water pollution.
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An imaginary planet was just discovered that has a similar environment to our planet Earth. All the chemistry is similar except for the values of bond energies. Use the planet's given bond energies to calculate the enthalpy of reaction for the combustion of 1 mole of pentane.
Enter a number to O decimal places in kJ/mol
Bond Energy (kJ/mol)
H-H 585
C-H 257
H-O 478
C-C 370
C C 779
CC 992
0-0 490
C-0 251
C-0 740
Answer: [tex]\Delta H_{rxn}=-4652[/tex] kJ/mol
Explanation: In a reaction, a bond of a molecule can break or rearrange itself. When it happens, it absorb or release energy.
Bond Energy is the energy necessary to break or to make a particular bond, producing gaseous fragments at atmospheric temperature. This type of energy can be used to show how stable a compound is or how easy a bond can break.
Enthalpy of Reaction is the energy absorption or release at a constant temperature resulting from a chemical reaction.
To calculate the Enthalpy using bond energy, you have:
1) Write the balanced equation with all the all the reactants and products in gaseous form:
[tex]C_{5}H_{12}_{(g)}+8O_{2}_{(g)}[/tex] ⇒ [tex]5CO_{2}_{(g)}+6H_{2}O_{(g)}[/tex]
2) Count each bond of each molecule from both sides, including double or triple bonding, if they exists:
Reactants:
[tex]C_{5}H_{12}[/tex] : 12 C-H
4 C-C
O₂ : 1 O=O
Products:
CO₂ : 2 C=O
H₂O : 2 H-O
3) From the balanced reaction, we there are 8 moles of oxygen gas, 5 moles of carbon dioxide and 6 moles of water, which has to be included when adding each side.
[tex]\Sigma H_{reactants}=[/tex] 12.257 + 4.370 + 8.490 = 8484
[tex]\Sigma H_{products}=[/tex] 5.2.740 + 6.2.478 = 13136
4) Calculate Enthalpy of Reaction by:
[tex]\Delta H_{rxn}= \Sigma H_{reactants}-\Sigma H_{products}[/tex]
[tex]\Delta H_{rxn}=8484-13136[/tex]
[tex]\Delta H_{rxn}=-4652[/tex]
The enthalpy of reaction for the combustion of 1 mole of pentane on a just discovered imaginary planet is an exothermic process of magnitude [tex]\Delta H_{rxn}=[/tex] - 4652kJ/mol
Using the planet's given bond energies to calculate the enthalpy of reaction, the combustion of 1 mole of pentane is -4652 kJ.
The balanced chemical reaction for the combustion of pentane is well represented as:
[tex]\mathbf{C_5H_{12}+8O_2 \to 5CO_2+6H_2O}[/tex]
From the above reaction, the bonds broken are 12 Carbon-Hydrogen bonds, 4 Carbon-Carbon bonds, and 8 oxygen-oxygen bonds.
Similarly, the bonds formed are 10 Carbon-Oxygen bonds and 12 Oxygen-hydrogen bonds.
Hence, the energy absorbed when bonds are broken are:
= 12(C-H) + 4(C-C) + 8(O-O)
= 12(257 kJ) + 4(370 kJ) + 8(490 kJ)
= 3084 kJ + 1480 kJ+ 3920 kJ
= 8484 kJ
Also, the energy released as a result of the formation of bond is:
= 10 (C=O) + 12 (O-H)
= 10 (740 kJ) + 12 (478 kJ)
= 7400 kJ + 5736 kJ
= 13136 kJ
From above, we can notice that the energy released during the formation of bonds is greater than the energy absorbed while breaking bonds.
Thus, the enthalpy of the combustion reaction is the difference in energy.
i.e.
The enthalpy of the combustion reaction = 8484 kJ - 13136 kJ
= -4652 kJ
Therefore, we can conclude that the enthalpy of reaction from the combustion of 1 mole of pentane is -4652 kJ. The negative sign indicates that more energy is released compared to the amount of energy absorbed.
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A sample of water has a mass of 193 g. Salt is added to the water, and the final solution weighs 238 g. How much salt was added? Please help no rush needed but this is due today but no rush..........Thank you so much.
Answer:
45 g of salt was added
Explanation:
238g-193g=45g
PLEASE HELP !!!! How many grams of lithium sulfate
(Li2SO4) are required to dissolve in
459 g of water to make a 1.23 m
solution?
[?]g Li2SO4
Molar mass of Li2SO4: 109.94 g/mol
Answer:
I think you need to dissolve 62.116 (or 62.12g) of Li2SO4 .
The mass of lithium sulfate needed is 62g
What is Molality?Molality is also known as molal concentration. It is a measure of solute concentration in a solution. The solution is composed of two components; solute and solvent.
It is defined as the moles of the solute present in 1kg of the solvent. It is denoted by 'm'.
This term is useful in understanding the concentration of a solution because its formula is independent of temperature and pressure. Thus, the colligative properties are dependent on molality.
Given,
Molality of solution = 1.23m
Mass of solvent ( water) = 459g
Molality = number of moles of solute ÷ mass of solvent in kg
number of moles of solute = molality × mass of solvent in kg
= 1.23 × 0.459
= 0.564 moles
moles = mass / molar mass
mass= 0.564 × 109.94
= 62 g
Therefore, the mass of lithium sulfate needed is 62g
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Which of the following most readily undergoes an E2 reaction with sodium ethoxide (NaOCH2CH3)?A) (CH3)CF.
B) (CH3)CCl.
C) (CH3)CBr.
D) (CH3)CI.
Answer:
(CH3)CI
Explanation:
As we move down the group, the halogen atoms become more easily polarizable and the C-X bond is more easily broken.
Recall that E2 mechanism has to do with synchronous proton abstraction and loss of the halogen.
These occur faster with (CH3)CI than when the C-X bond involves other halogens.
Assume that a film includes repeated scenes showing the trademark Voom on the sports shoes of its attractive adolescent protagonists. Althoughthe film is successful among young audiences, no increase occurs in the sale of Voom shoes. Which of the following hypotheses about this outcome is the most plausible on the basis of the studies cited?
A) Audiences feel uncomfortable because Voom is an unfamiliar brand.
B) Most members of the audience already own a pair of Voom shoes.
C) Audiences are worried by the social implications of these scenes.
D) Audiences are too engrossed in the story to notice the shoes.
Answer: D
Explanation: Even if the audiance did not have a pair of shoes felt uncomfortable or worried not a lot of people would have noticed. If anyone noticed it would only be about 5% of people so that is how I came to the conclision of D.
The graph models the amount remaining, in milligrams, of a radioactive substance as a function of time, in years. Explain the meaning of the point (3100) shown on the graph. Answer in complete sentences.
Answer:
Where is the grahppppp?!!!!
What makes a compound
polar?
Answer:
Polar molecules occur when two atoms do not share electrons equally in a covalent bond. ... If the electronegativity difference between the atoms is greater than 2.0, the bond is ionic. Ionic compounds are extremely polar molecules.
Explanation:
what is the formula for calculating heat energy when there is a change in temperature.
Answer:
Q = m.c. ΔT
Explanation:
When temperature is changed the heat evolved or absorbed are calculating by following formula.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
When temperature is decreased heat is evolved and negative sign is added into Q value.
When temperature is increased heat is absorbed by system and positive sign is added with Q value.
PLEASE HURRY FAST MY TEACHER SAID SHE WILL BE GRADING THIS AND IF WE DON'T DO IT WE WILL FAIL AND I AM ONE OF THE PEOPLE WHO DID NOT DO IT YET. Question: it says look at the table of some properties of three substances. Here are the three substance: X, Y, or Z. Color: light brown, light brown, dark brown. Texture: smooth ,rough, spongy. Smell: strong odor, strong odor, odor. NOW IT SAY. You are given a substance listed in this table. What is the best way to identify the substance as X, Y, or Z PLEASE HELP ME PLEASE. AND HERE ARE THE ANSWERS THEY GAVE US: A. feel it, b. look at the color, c. smell it, d. Find mass
Answer:
C. Smell it
Explanation:
Yolo it and if im right then i deserve a 5 star :)
Answer:
honestly If I were that person I would go with feeling to figure out the texture because thats the most distinctive thing but I could be wrong. Good Luck.
Explanation:
Explain the law of conservation of energy. Give a specific example using kinetic and potential energy that shows how energy is conserved.
Answer:
Law of conservation of energy states that energy can neither be created nor can be destroyed but can be changed from one form to another
example:I am quite confused Sorry....❤plz follow me
What is the percent composition of carbon in K2CO3?
Answer:
8,68%
Explanation:
12g/mol de C divided by 138,2 g/mol de K2CO3
0.0868 x 100 = 8.68 %
If I tripled the number molecules of Ag2 SO4 from 1 to 3 how would this effect this compound ?
Answer:
AgCl(s)
dissolution
⇌
precipitation Ag+(aq)+Cl−(aq)
Explanation:
dynamic; some of the solid AgCl continues to dissolve, but at the same time, Ag+ and Cl– ions in the solution combine to produce an equal amount of the solid. At equilibrium, the opposing processes have equal rates.
Liquid boils faster at mountain region than in terai region. why?
Answer:
are you silly your question is opposite silly
Answer:
beacuse this reason has lower atmospheric pressure due to a thinner blanket of air above. ... As atmospheric pressure decreases, liquid boils at lower temperatures. due to which it takes less time than terai region