Explanation:
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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
. FAST PLEASE HELP Which of the following is true about ALL energy transformations?
Energy never changes forms, only the amount of energy changes
The end product of all energy transformations is chemical energy
The end product of all energy transformations is electrical energy
Energy is never lost, it just changes from one form to another
Answer:
Energy is never lost, it just changes from one form to another
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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Explain the 2 main differences between ionic and covalent bonds and identify if the compound CaF2
will have an ionic or covalent bond and why.
Answer:
yes. because look at the equation it will have an ionic bond
Explanation:
What Celsius temperature, T2, is required to change the volume of the gas sample in Part A (T1 = 42 ∘C , V1= 1.10×103 L ) to a volume of 2.20×103 L ? Assume no change in pressure or the amount of gas in the balloon.
Answer:
The temperature that is required is 357 C.
Explanation:
Charles's Law consists of the relationship that exists between the volume and the temperature of a certain quantity of ideal gas, which is maintained at a constant pressure, by means of a constant of proportionality that is applied directly. For a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement of the gas molecules. .
In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the ratio between the volume and the temperature will always have the same value:
[tex]\frac{V}{T} =k[/tex]
Now it is possible to assume that you have a certain volume of gas V1 that is at a temperature T1 at the beginning of the experiment. If you vary the volume of gas to a new value V2, then the temperature will change to T2, and it will be true:
[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]
In this case:
V1= 1.10*10³ LT1= 42 C= 315 K (being 0 C=273 K)V2= 2.20*10³ LT2= ?Replacing:
[tex]\frac{1.10*10^{3}L }{315 K} =\frac{2.20*10^{3}L }{T2}[/tex]
Solving:
[tex]T2=\frac{2.20*10^{3}L }{ \frac{1.10*10^{3}L }{315 K} }[/tex]
T2=630 K= 357 C
The temperature that is required is 357 C.
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.
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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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:
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.
Sulfuric acid, H 2 S O 4 , is an important industrial chemical, typically synthesized in a multi-step process. What is the percent yield if a batch of H 2 SO 4 has a theoretical yield of 3.4 kg, and 2.7 kg are obtained at the end of the process
Answer:
79.4 %
Explanation:
From the question given above, the following data were obtained:
Theoretical yield = 3.4 kg
Actual yield = 2.7 kg
Percentage yield =?
Percentage yield is simply defined as the ratio of the actual yield to that of the theoretical yield multiplied by 100 i.e
Percentage yield = Actual yield/Theoretical yield × 100
With the above formula, we can obtain the percentage yield as follow:
Theoretical yield = 3.4 kg
Actual yield = 2.7 kg
Percentage yield =?
Percentage yield = Actual yield/Theoretical yield × 100
Percentage yield = 2.7/3.4 × 100
Percentage yield = 79.4 %
Thus the percentage yield is 79.4 %
The percent yield is 79.4%
Percentage yieldFrom the question,
We are to determine the percent yield.
Percent yield is given by the formula,
[tex]Percent\ yield = \frac{Actual\ yield}{Theoretical yield } \times 100\% [/tex]
From the given information,
Actual yield = 2.7 kg
Theoretical yield = 3.4 kg
Putting the parameters into the formula,
[tex]Percent\ yield = \frac{2.7}{3.4} \times 100\% [/tex]
Then,
[tex]Percent\ yield = 0.7941176\times 100\% [/tex]
[tex]Percent\ yield = 79.4\% [/tex]
Hence, the percent yield is 79.4%
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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:
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:
Steve wants to investigate the expansion and contraction of gases at different temperatures. He knows that at higher temperatures, gas particles move faster. His hypothesis is that at higher temperatures the faster particle motion causes gas to expand. He fills three balloons with the same amount of gas and heats the gas in each balloon to different temperatures. The test (independent) variable is the temperature of the gas. Which statement describes how the outcome (dependent) variable changes as a result of the changes made to the tested (independent) variable?
Answer: C. Gas particles move faster and farther apart at higher temperatures.
Explanation:
The options include:
A. the number of gas particles increases at higher temperatures
B. the number of gas particles decreases at higher temperatures
C. gas particles move faster and farther apart at higher temperatures
D. gas particles move more slowly and get closer together at higher temperatures
The statement that describes how the outcome (dependent) variable changes as a result of the changes made to the tested (independent) variable is that gas particles move faster and farther apart at higher temperatures.
It should be noted that the particles in the gases will collide more frequently with one another because of the shorter space that is between them.
The increase in the temperature will bring about a faster movement of the particles which in turn, brings about a rise in the diffusion rate and also the collision rate.
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 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
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
50 pts
With 11 electrons how many electron shells does sodium have?
3
4
2
1
Answer: 3
Explanation:
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
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
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 %
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.
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?!!!!
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.
I’m trying to answer this question
Answer:
her speed is constant as she runs, and her av. speed is 3 m/sec
Explanation:
av speed is total distance divided by total time, so 150/50=3
Why are marine mammals so important
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]
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.
Complete the mechanism for the electrophilic addition when the alkene is treated with water in acid.
Answer:
CH₃CH == CH₂ + H₂O → H⁺ → CH₃CH(OH)CH₃ + H⁺
The reaction of propene and water in acidic medium produces isopropyl alcohol.
Explanation:
Let's propose the following reaction:
Propene + H₂O in H⁺ medium → Alcohol
CH₃CH == CH₂ + H⁺ → CH₃C⁺CH₂
Electrons from the double bond attack the proton. So the double bond is broken and you form a carbocation.
Carbocation will be attacked by the electrons from the oxygen on the molecule of water.
CH₃C⁺CH₂ + H₂O: : → CH₃ _CH _ CH₃
|
⁺OHH
It is called electrophilic addition cause the proton which is the electrophile is added to the sp₂ carbon in the alkene (where many H are bonded), and the nucleophile, water is added to the other sp₂ carbon.
This last attack is so fast that the carbocation is combined with any nucleophile which it collides first. In the hydration reaction, there are two nucleophiles: water and the anion from the acid (let's think Cl⁻, cause our medium can be HCl). The product of this collision is a protonated alcohol. Since we know that protonated alcohols are very strong acids, this protonated alcohol loses a proton, and the end product of the addition reaction is an alcohol.
In the first step, a proton adds to the alkene, but is returned to the reaction mixture during the final step, when the alcohol is deprotonated.
CH₃ _CH _ CH₃ → CH₃ _CH _ CH₃ + H⁺
| |
⁺OHH OH
Use the following balanced equation to answer the following questions:
CH4 + 2 O2 → CO2 + 2 H2O
For every 10 g of CH4 reacted, how many grams of CO2 is produced?
NEED ASAP
Answer:
27.5 gram
Explanation:
16 gram CH⁴ gives 44 gram CO²
1 gram CH⁴ gives 44/16 gram CO²
10 gram CH⁴ gives (44/16)×10 gram CO²=27.5 gram Co²
2. How can where you live affect the amount of available water to use?
Answer:
Water is life, as the saying goes. We rely on water for our food, our health, our livelihoods, and for fun and leisure. But water can also take away life, and the absence of water can be even worse. Currently, 700 million people live in water-stressed areas. By 2025, this number is expected to grow 1.8 billion — about 25% of the world population.
As Number 6 on the UN’s Sustainable Development Goals, “Clean Water and Sanitation For All” is currently struggling. The UN suggests that, if we want to meet this goal by the deadline of 2030, we’ll need to double our current rate of progress to ensure that there’s universal access to safe and affordable drinking water, adequate sanitation and hygiene resources, improved water quality, and restored water-related ecosystems. Here are 5 ways that water affects our lives — and what we’re doing to help make them happen.
Explanation:
Many of the towns we live in were built near water sources. Oceans, rivers, streams and lakes make up some of our geographical boundaries. They also allow for water transportation and commerce and provide food and other resources.