The second statment is true and right. Hope this helps!!
Answer: Option (b) is the correct answer.
Explanation:
Freezing point is defined as the point at which liquid state of a substance changes into solid state.
So, in the given table it is shown that at temperature [tex]18^{o}C[/tex] the substance is changing into solid state. Whereas at [tex]23^{o}C[/tex] the substance is in liquid state.
Hence, [tex]18^{o}C[/tex] will be the freezing point of the substance.
Thus, we can conclude that the statement its freezing point is [tex]18^{o}C[/tex], is correct about the unknown substance.
Andrea is performing an experiment in which she needs to know when a strong acid is present. She is not sure which indicator to use, so she looks up the following table in her science textbook.
Indicator pH range
thymol Blue 1.2 - 2.8
phenol Red 6.4 - 8.0
phenolphthalein 8.0 - 10.0
trinitrobenzoic acid 12.0 - 13.4
According to the textbook, which indicator should Andrea use?
Hint: Neutral substances have a pH of 7. Acids have a pH that is less than 7, and bases have a pH that is greater than 7.
A.
phenolphthalein
B.
phenol Red
C.
thymol Blue
D.
trinitrobenzoic acid
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Answer:
c- thymol blue
Explanation:
study island
According to the textbook, the indicator that should Andrea use is thymol blue. Thus, the correct option for this question is C.
What is Strong acid?Strong acid may be defined as a type of acid that is completely dissociated or ionized in an aqueous solution. It is a type of chemical species that typically have the ability to lose a proton, H+. Examples of strong acids include sulphuric acid, hydrochloric acid, nitric acid, etc.
Acids range the pH lower than 7. While exactly 7 is a neutral compound. In the experiment, Andrea was required to know when a strong acid is present, so she utilizes an indicator. For this, she used the indicator that has the pH of strong acid.
Among the options given above, the indicator thymol blue demonstrates the same qualities and characteristics.
Therefore, the indicator that should Andrea use is thymol blue. Thus, the correct option for this question is C.
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There are many methods used to obtain energy for use in our daily lives. Some of these methods have possible environmental consequences to rivers, groundwater, and organisms. One type of pollution involves excess carbon dioxide being released into the air. Some of the carbon dioxide reacts with water to form acid rain. Which energy sources can release carbon dioxide and carbon monoxide waste into the atmosphere?
A) wind and solar
B) wind and nuclear
C) solar and nuclear
D) coal and petroleum
What is the consumption of dietary supplememts considered risky
Hello there!
Sometimes it is good to go on a diet for us. Other times, (we may not realize it), but it can be risky for our health and bodies. While getting more vitamins can be healthy and good for us, too much of the same vitamins in our body can be unhealthy, and even cause scary side effects. Do not be misled, the title “vitamin”, does not mean “use generously”. Just as we are to limit our eating of unhealthy foods, we need to limit our use of just vitamins as well.
For example, while vitamin A can be beneficial for our bodies in some ways, too much of it can liver damage, headaches, reduce bone strength, and in very serious cases even birth defects to children, or one conceiving a child. Yes, we need just enough to keep us healthy an active. There can only be so many problems with the human body, and using too many dietary supplements should not be one of them.
Hope this helps!
~DL
What’s the IUPAC name for CH2=C(CH2CH3)2?
The IUPAC name for the compound CH2=C(CH2CH3)2 is 2,3-diethylbut-1-ene, with the double bond starting at the first carbon of the four-carbon main chain.
Explanation:The student is asking for the IUPAC name of the chemical compound with the molecular formula CH2=C(CH2CH3)2. This compound is an alkene with two ethyl groups attached to the carbon-carbon double bond. The longest carbon chain that includes the double bond has four carbon atoms. Therefore, the base name is butene. Since there are two identical substituents (ethyl groups), the correct IUPAC name is 2,3-diethylbut-1-ene. In naming the compound, the ethyl groups are listed in alphabetical order and the number 1 indicates the position of the double bond.
How are elements arranged in the Periodic Table? A. by their properties B. alphabetically C. by how much they are worth D. in the order they were discovered 2. (10 pt) Which is the correct symbol for the element silicon? A. SI B. S C. Si D. Sil 3. (10 pt) All atoms of an element are ________ . A. flammable B. visible under a microscope C. alike D. different 4. (10 pt) Elements that are usually shiny and good conductors of heat and electricity are known as ________________. A. gases B. metals C. solids D. nonmetals 5. (10 pt) The most recent model of an atom is the _______________. A. Bohr model B. Einstein model C. Nucleus model D. Electron Cloud model 6. (10 pt) Elements that are usually dull, brittle, and do not conduct electricity are known as A. gases B. metals C. solids D. nonmetals 7. (10 pt) Elements join together to form A. compounds B. ions C. protons D. atomic masses 8. (10 pt) Which picture best shows an atom? A. B. C. D. 9. (10 pt) In order for a chemical reaction to take place, a certain amount of _______________ must be present. A. heat B. friction C. chemicals D. energy 10. (10 pt) Enzymes are ____________ in the body that speed up chemical reactions. A. catalysts B. cells C. concentrations D. chloroplasts
Answer:
In the modern periodic table, the elements are listed in order of increasing atomic number. The atomic number is the number of protons in the nucleus of an atom. ... In a periodic table arranged in order of increasing atomic number, elements having similar chemical properties naturally line up in the same column
Explanation:
I hope this helps
Final answer:
The Periodic Table is arranged by their properties, with elements grouped according to similar chemical and physical characteristics. Silicon is represented by the symbol Si, and all atoms of an element are alike. Metals are shiny and good conductors, while nonmetals are dull and poor conductors.
Explanation:
1. Elements in the Periodic Table are arranged by their properties, therefore, the correct answer is A. by their properties.
2. The correct symbol for the element silicon is C. Si.
3. All atoms of an element are alike, meaning the correct answer is C. alike.
4. Elements that are usually shiny and good conductors of heat and electricity are known as B. metals.
5. The most recent model of an atom is the D. Electron Cloud model.
6. Elements that are usually dull, brittle, and do not conduct electricity are D. nonmetals.
7. Elements join together to form A. compounds.
8. For the picture that best shows an atom, since images can't be displayed here, one should typically look for a depiction that includes a nucleus surrounded by electrons, which represents the Electron Cloud model.
9. In order for a chemical reaction to take place, a certain amount of D. energy must be present.
10. Enzymes are A. catalysts in the body that speed up chemical reactions.
Select all that apply.
How may the concentration of chloroform be increased as Cl2 gas reacts with CH2Cl2?
increase [HCl]
remove HCl from the product
increase [Cl2]
the rate of reaction cannot be changed
Answer:
increase [Cl₂]
remove HCl from the product
Explanation:
Odyssey ware
Which object in the diagram represents earths moon
This is Stoichiometry and I need part 2 and 3
Answer:
did u get it
Explanation:
Someone help me please!
Na2SO4 is dissolved in water to make 450 mL of a 0.250 M solution. What is the molar mass of Na2SO4, and how many moles are needed?
Name at least two Benefits of using models in science
Answer:
Models make concepts more tangible. They also make it possible to notice patterns, develop or revise representations, and predict or explain events or relationships.
Explanation:
Trust me it's the answer okay
Infer if the mineral Talc would be a good choice when building a statue outside. Justify your answer with your knowledge of minerals and acid/bases. According to your data, would there be a better mineral to use? If so, which one and why?
You are given the percent by mass of the elements in a compound and wish to determine the empirical formula. Label each of the following statements as true or false and explain your answers.
a. You must assume exactly 100.0 g of the
compound.
b. You must convert percent by mass to relative
numbers of atoms.
c. You must divide all of the percent by mass
numbers by the smallest percent by mass.
d. You cannot solve for the emp
How does the radioactive isotope C-14 differ from its stable counterpart C-12?
Isotope is defined as atom of same element with same atomic number but different mass number.
Here, atomic number for C-14 and C-12 is 6 but mass number is 14 and 12 respectively.
Atomic number is equal to number of protons and electrons in an atom and mass number is equal to sum of number of protons and neutrons in nucleus of an atom.
[tex]A=n_{p}+n_{n}[/tex]
Since, both have same atomic number, the number of protons will be 6 for both but they have different number of neutrons.
Number of neutrons in C-12:
[tex]n_{n}=12-n_{p}=12-6=6[/tex]
Number of neutrons in C-14:
[tex]n_{n}=14-n_{p}=14-6=8[/tex]
The number of neutrons in C-12 is 6 and that in C-14 is 8. Therefore, isotope C-14 differ from the stable C-12 in number of neutrons.
_______ reaches the Earth's surface through _______, then turns into _______.
Answer:
Magma, Volcano, Lava
Explanation:
During the time of convergence of two plates, the subduction zone is created due to the sinking of the heavier plate below the lighter one. The long, narrow depression, commonly known as trench forms above this zone of subduction.
As the heavier plate goes down, it melts and mixes with the magma. This magma then rises upward due to the force exerted by the large convection currents, which eventually reaches the earth's surface towards the over-riding plate, giving rise to the formation of volcanoes.
When the uplifting of magma is large and rapid, then it erupts on the surface, and undergoes solidification, forming lava.
Thus, the magma reaches the surface of the earth through the formation of volcano and solidifies as lava.
What is the difference between creep and a landslide?
A creep is a slow downhill movement of weathered rock material.
A landslide is a sudden movement of rock and soil down a slope.
Basically, creeps are slower than landslides.
a sample of methane gas having a volume of 2.8 L at 25°C and 1.65 atm was mixed with a sample of oxygen gas having a volume of 35L at 31°C and 1.25 atm. The mixture was ignited to form carbon dioxide and water. Calculate the volume of carbon dioxide formed at a pressure of 2.5 atm and a temperature of 125°C
[tex]\left[\begin{array}{cccc}&Volume(L)&Pressure(atm)&Temperature(K)\\Methane&2.8&1.65&298\\Oxygen&35&1.25&304\end{array}\right][/tex]
note: K = C° + 273 (Temperature conversion, Celsius to Kelvin)
Find moles of methane and oxygen:note: [tex]Ideal \ Gas \ Law: \ PV=nRT \ \ \ (R = 0.082 \ \frac{L \times atm }{K \times mol} )[/tex]
Formula to find moles is: [tex]n=\frac{PV}{RT}[/tex]
[tex]\space \\CH_{4} \ : \ n = \frac{1.65 \times 2.8}{298 \times 0.082} = 0.19\ mol \ (limiting \ reactant)[/tex]
[tex]O_{2} \ : \ n = \frac{1.25 \times 35}{304 \times 0.082} = 1.75\ mol \ (2 \times 0.19 = 0.38 \ mol \ is \ enough)[/tex]
note: moles of CO₂ is the same as of CH₄, as can be seen from the chemical equation above, which is 0.19 mol.
Find volume of CO₂:[tex]\left[\begin{array}{ccccc}&Volume(L)&Pressure(atm)&Temperature(K)&Moles(mol)\\CO_{2} &?&2.5&398&0.19\end{array}\right][/tex]
Formula to find Volume is: [tex]V=\frac{nRT}{P}[/tex]
[tex]CO_{2} \ : \ V = \frac{0.19 \times 0.082 \times 398}{2.5} = 2.48 \ L[/tex]
So, the answer is: 2.48 Lhow many moles of barium hydroxide, Ba(OH2), would be required to react with 117 g hydrogen bromide, HBr?
The correct calculation yields 0.724 moles of Ba(OH)₂, not 2.93, indicating a mistake in the given answer's stoichiometry interpretation.
To react completely with 117 g of hydrogen bromide (HBr), 2.93 moles of barium hydroxide (Ba(OH)2) would be required.
First, we need to write the balanced chemical equation for the reaction between barium hydroxide and hydrogen bromide:
[tex]\[ \text{Ba(OH)}_2 + 2\text{HBr} \rightarrow \text{BaBr}_2 + 2\text{H}_2\text{O} \][/tex]
From the balanced equation, we can see that 1 mole of barium hydroxide reacts with 2 moles of hydrogen bromide.
Next, we need to calculate the number of moles of hydrogen bromide (HBr) present in 117 g. The molar mass of HBr is 80.91 g/mol (1.008 g/mol for H and 79.90 g/mol for Br).
[tex]\[ \text{moles of HBr} = \frac{\text{mass of HBr}}{\text{molar mass of HBr}} \][/tex]
[tex]\[ \text{moles of HBr} = \frac{117 \text{ g}}{80.91 \text{ g/mol}} \][/tex]
[tex]\[ \text{moles of HBr} =1.448 \text{ moles} \][/tex]
Now, using the stoichiometry of the balanced equation, we can find the moles of barium hydroxide required:
[tex]\[ \text{moles of Ba(OH)}_2 = \frac{1}{2} \times \text{moles of HBr} \][/tex]
[tex]\[ \text{moles of Ba(OH)}_2 = \frac{1}{2} \times 1.448 \text{ moles} \][/tex]
[tex]\[ \text{moles of Ba(OH)}_2 =0.724 \text{ moles} \][/tex]
However, the given answer is 2.93 moles, which suggests that there might be a mistake in the calculation. Let's re-evaluate the moles of HBr:
[tex]\[ \text{moles of HBr} = \frac{117 \text{ g}}{80.91 \text{ g/mol}} \][/tex]
[tex]\[ \text{moles of HBr} =1.448 \text{ moles} \][/tex]
Since the stoichiometry of the reaction is 1 mole of Ba(OH)2 to 2 moles of HBr, the correct calculation for the moles of Ba(OH)2 required should be:
[tex]\[ \text{moles of Ba(OH)}_2 = 1.448 \text{ moles HBr} \times \frac{1 \text{ mole Ba(OH)}_2}{2 \text{ moles HBr}} \][/tex]
[tex]\[ \text{moles of Ba(OH)}_2 = 0.724 \text{ moles} \][/tex]
It appears that the provided answer of 2.93 moles of Ba(OH)₂ is incorrect based on the stoichiometry of the reaction and the calculations performed. The correct answer should be 0.724 moles of Ba(OH)₂. There seems to be a discrepancy between the provided answer and the calculated result. The correct answer, based on the calculations, is 0.724 moles of barium hydroxide, not 2.93 moles.
5.
The diagram illustrates part of the carbon cycle.
Which best describes the diagram?
A consumer is obtaining carbon by breathing it in from the atmosphere.
A consumer is obtaining carbon by absorbing it from the soil.
A consumer is obtaining carbon by eating carbon-based molecules stored in a producer.
A consumer is obtaining carbon by eating carbon-based molecules stored in a decomposer.
Answer:
The correct answer is "A consumer is obtaining carbon by eating carbon-based molecules stored in a producer".
Explanation:
The animal is consuming the carbon present in the molecules stored in the grass. Plants process the carbon present in the soil along with other minerals. The animal, when it feeds on these plants, is consuming the carbon they obtained from the soil. Grasslands are defined largely by their use for grazing, which includes between 10 and 30 percent of soil carbon worldwide.
Have a nice day!
Answer:
C
Explanation:
it was right on (edge nuity)
What is an abiotic factor in a squirrel's habitat that could be harmful if the factor changed
the rows on the periodic table correspond to
Which information is represented by a line on this map?
A. points with the same elevation
B. the location of a road
C. a direction north or south
D. a direction east or west
what is the molarity of a solution of calcium chloride which contains 33500mg of solute in total volume of 0.352L?
what is the simplest alkane
Answer: C. Methane
Explanation:
How are the sparks from a sparkler that strike your skin akin to tiny droplets o boiling water striking your skin?
Final answer:
The sparks from a sparkler and tiny droplets of boiling water both have high thermal energy, transferring this energy to the skin upon contact, causing a burn. A static electricity spark from a doorknob is too brief to harm you. Steam burns are worse than boiling water because of the release of latent heat.
Explanation:
When a sparkler comes into contact with your skin, the hot sparks cause a sensation similar to tiny droplets of boiling water hitting your skin. Both the sparks and the boiling water droplets have a high amount of thermal energy. When they come into contact with your skin, they transfer some of this energy to your skin cells, causing a burn. The transfer of energy in both cases is rapid and occurs over a very small area of contact, leading to a high concentration of energy which can be quite painful.
In the case of a static electricity spark from a doorknob, which can carry a few hundred watts of power, the reason you're not injured is that the spark is very brief. It doesn't last long enough to transfer a significant amount of energy to cause harm. The situation is unlike with a sustained contact with something hot, where energy transfer is more prolonged.
Similarly, when steam condenses on your skin, it releases latent heat, which causes a burn. The latent heat is the energy that was used to break the hydrogen bonds when turning water into steam. When steam condenses back to water on your skin, it releases this energy, causing a more severe burn than boiling water would at the same temperature.
how many grams are there in 0.250 moles of sodium hydroxide
Answer: The mass of sodium hydroxide is 10 grams.
Explanation:
To calculate the mass of a substance, we use the equation to calculate the number of moles, we get:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
We are given:
Moles of sodium hydroxide = 0.25 mol
Molar mass of sodium hydroxide = 40 g/mol
Putting values in above equation, we get:
[tex]0.25=\frac{\text{Mass of sodium hydroxide}}{40g/mol}\\\\\text{Mass of sodium hydroxide}=10g[/tex]
Hence, the mass of sodium hydroxide is 10 grams.
Explain how the law of conservation of mass allows you to predict the total Mr of the products.
Mass is never lost or gained in chemical reactions. So we can say that mass is always conserved. In other words, the total mass of products at the end of the reaction is equal to the total mass of the reactants at the beginning.
This fact allows you to work out the mass of one substance in a reaction if the masses of the other substances are known.
A scientist did an investigation on the growth of koi fish. He selected forty newly hatched koi from the same clutch of eggs. He separated the koi into four groups and placed each group in a different sized pond. None of the ponds had any predators that would eat the koi fish. The amount of food available to the koi and the water quality of each pond differed based on the size of the pond. Larger ponds had more food available and better water quality as the fish grew.
After 15 months, the scientist measured the length of each koi fish. Using these measurements, he came up with an average koi size for each pond.
Effect of Pond Size on Koi Fish Growth
Size of Pond Average Length of Koi
500 gallons 18.2 centimeters
1000 gallons 25.6 centimeters
2500 gallons 30.8 centimeters
5000 gallons 35.3 centimeters
Based on the scientist's results, which of the following is true?
A.
Koi fish grow fastest in ponds with poor water quality.
B.
Koi fish grow fastest in ponds with a high population density.
C.
The growth of koi fish is determined entirely by genetics.
D.
The growth of koi fish is affected by the environment of the fish.
Answer:
d
Explanation:
just did it
From the results, it is clear that, the growth of the koi fish is depending on the environment in which it grows. This include, the size of pond, food available, water quality, presence of predators etc. Hence, option D is correct.
What are environmental factors affecting fish growth ?The condition of the water in which fish are grown directly affects their health and eventual growth. In general, physical, chemical/biochemical, or a combination of these components can be used to categories factors impacting fish growth and productivity in freshwater aquatic systems.
Temperature and suspended and settleable particles concentrations are significant physical water characteristics for the development and growth of fish; crucial chemical water characteristics include pH, alkalinity, hardness, and metal concentrations.
The adequate size of pond let the fish free to move more and make it more energetic with the surroundings. Hence, the growth of koi fish is affected by the environment of the fish.
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.817g of an unknowm gas occupies 1.25L at 27.0°C and a pressure of 765 mmhg. is the gas most likely methane(CH4), ethane(C2H6), propane(C3H8), or butane(C4H10)? please show work.
What energy transformations occur between the microwave oven and the meal? *